Myths, Men, and the Minority Report: The crash of Arrow Air flight 1285
On the 12th of December 1985, a chartered DC-8 carrying United States military personnel home from a mission in the Sinai Peninsula crashed on takeoff from a fuel stop in Gander, Newfoundland, killing all 256 people on board in what remains the deadliest air accident on Canadian soil. The disaster presented an enormous challenge to Canada’s air safety investigators, who faced a vast scene of desolation and an aircraft reduced to rubble, compounded by a faulty cockpit voice recorder and a barely functional data recorder. Considering this lack of evidence, it was unfortunate but not surprising that the inquiry split along political lines, dividing into two radically divergent camps who never came to an agreement about the cause of the accident. Was Arrow Air flight 1285 brought down by ice on the wings and a miscalculated weight, or was it ripped from the sky by an in-flight explosion, either accidental, or worse, deliberate? While much remains unknown about what happened on that dark morning in 1985, the difference of opinion about the cause is not what it seems — and the two camps should hardly be presented on equal terms. In fact, the dispute over the cause may have originated well before the accident actually happened, in a smoldering disagreement within the Canadian Aviation Safety Board — one which, propelled by the disaster in Gander, burst so dramatically into the open that it led to the demise of the Safety Board itself, leaving a bitter legacy of uncertainty and misinformation.
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Founded in 1947 in Compton, California, and later based in Miami, Arrow Air was a jack-of-all-trades airline, known for using old aircraft to fill some of the airline market’s scrappier niches. For many years it operated both scheduled and charter cargo flights throughout the US and Latin America, while also carrying passengers on an eclectic and ever-changing route network that sometimes included transatlantic services, although the company primarily connected cities in the eastern US and Canada with underserved destinations in the Caribbean. And although the trips never made up a significant share of Arrow Air’s business, the company also flew passenger charters, including — briefly — for the US military.
In October of 1985, Arrow Air signed a contract with the Department of Defense in order to transport troops to and from bases in Egypt’s Sinai Peninsula as part of the United Nations-backed Multinational Force and Observers peacekeeping mission, which was intended to enforce peace between Egypt and Israel in the wake of the 1978 Camp David Accords. Soldiers of the United States Army participated in the mission, and in fact the US still has around 450 troops there to this day. Obviously, these are not the same troops who were there in 1985, or even the same ones who were there a year ago, because the military rotates them out on a regular basis — which is where Arrow Air enters the picture.
Arrow Air had already transported one rotation of troops between the United States and Egypt by the beginning of December 1985, when the second rotation began. At that time the unit being relieved was the famed 101st Airborne Division of the US Army, nicknamed the “Screaming Eagles,” whose central role in the D-Day invasion, the Battle of the Bulge, and other significant engagements have made it among the most famous units of America’s armed forces.
Arrow Air planned to carry up to 250 members of the 101st Airborne Division using its four-engine, narrow body, 1960s-era Douglas DC-8–60s, which were not capable of flying nonstop from the US to Cairo, necessitating a complex series of stopovers and crew changes. The first rotation departed from McChord Air Force Base in Washington State with a load of outbound troops, followed by fuel stops in Gander, Newfoundland and Cologne, Germany before the final leg into Cairo, where different aircraft picked up the soldiers and shuttled them to the US base in the Sinai. This process was then reversed, carrying the troops whose rotation had ended, proceeding back through Cologne and Gander before arriving at Fort Campbell, a US Army installation on the Kentucky-Tennessee border, where the 101st Airborne is based.
To operate this reverse journey, Arrow Air assigned two separate flight crews — one responsible for the Cairo-Cologne segments, both inbound and outbound; and a second crew responsible for the Cologne-Gander and Gander-Fort Campbell segments. A further segment from Fort Campbell to Oakland, California without passengers was tacked onto the end of the schedule as part of a single, mammoth duty day. These segments would be collectively known as flight 1285.
The trip from Cologne to Fort Campbell was originally supposed to carry 250 passengers, but one of them was rescheduled, and another had been denied boarding in Cairo after losing his passport, making for a final total of 248. Also on board were eight crewmembers, including three flight deck crew, consisting of 45-year-old Captain John Griffin, 45-year-old First Officer Joseph Connelly, and 48-year-old Flight Engineer Michael Fowler.
The aircraft, registration N950JW, was a Douglas DC-8–63 manufactured in 1969, and it had seen better days. The interior was reportedly quite shabby, with all sorts of faulty panels and other cosmetic damage. The airplane was not exactly flawless in mechanical terms either. It reportedly was leaking both hydraulic fluid and potable water at such a rate as to require frequent refills, but maintenance had not bothered to seek the source of the issues, nor were they being properly written up in the logs. Arrow Air pilots also knew that the №4 engine was indicating a higher than normal exhaust gas temperature, a problem that occurred again on the Cairo-Cologne leg, but company flight crews suspected that it was only an indicating issue. The flight engineer and first officer from the previous leg would also later testify that one of the thrust reverser unlock lights was flickering on and off in turbulence, but the captain denied this.
Despite these recurring defects, and a chaotic loading process in Cairo, N950JW made it to Cologne without incident, where the accident flight crew left their hotel at 2:00 on the morning of December 12th in order to pick it up. At that time they had been in Cologne, off duty, for about 15 hours, but it’s known that Captain Griffin had probably already been awake for around 7 of those hours by the time he left for the airport.
Nevertheless, the departure from Cologne and the transatlantic crossing both went off without a hitch, and at 5:34 a.m. local Newfoundland time, flight 1285 landed in Gander under conditions of pre-dawn darkness. The weather in Gander that morning was dreary but not exceptionally adverse, with overcast between 700 and 4,000 feet that occasionally spit out light snow, scattered snow grains, and sometimes very light freezing drizzle. Some aircraft that landed in Gander around the same time reported picking up ice on approach, but others didn’t. The tower weather observer noted some minor ice buildup on the airport’s ice detection system — really a piece of aircraft-grade sheet metal laid outside to collect precipitation — but not so much as to cause concern. Although de-icing services were available at Gander, the crew of flight 1285 made no request to use them.
After about an hour on the ground, during which time the crew inspected the aircraft and oversaw the loading of fuel, flight 1285 taxied back out to runway 22 for departure at 6:45. The fully loaded DC-8 was forced to take off not from the end of runway 22, but from its intersection with the crossing runway 13, because the area before the intersection hadn’t been cleared of snow. But with 9,900 feet (3,000 m) of runway available, there was still plenty of room for even a severely overladen DC-8 to become airborne safely.
As the tower controller looked on, the dark form of the aircraft sped away down the runway, its acceleration apparently normal. After some time its nose lifted up, and having covered 8,000 feet in 51 seconds, the DC-8 became airborne — at which point the sense of normality abruptly ceased. The controller and other witnesses watched with growing alarm as the jet failed to gain altitude, streaking across the end of the runway at only a few dozen feet above the ground. No distress call was made as the aircraft continued in near-level flight over the trees, at which point it began to descend, crossing over the Trans-Canada Highway, located about 900 feet (270 m) beyond the runway, at a very low altitude. Although darkness prevailed, several witnesses on the road spotted a glow as the plane passed low overhead, illuminating their vehicles in an eerie light. From the control tower, the airplane then appeared to descend below the tree line, following the down-sloping terrain toward Gander Lake, where it passed out of view.
Seconds later, Arrow Air flight 1285 impacted the tops of trees in a nose-high, right wing low attitude, some 3,000 feet beyond the runway end and 720 feet right of the runway axis. The plane carved a wide swath through the forest, slicing off hundreds of trees as it came down, like an immense scythe in the hands of a most cruel reaper. And then the DC-8 struck the ground hard; its tail section separated and the fuselage yawed sharply to the right, slewing across the rugged hillside before it slammed into a series of rock outcroppings, tearing the plane apart in an instant. The DC-8’s full fuel tanks ignited into a fireball of immense proportions, consuming the wreckage in a sea of flame that left the forest awash in an unearthly glow.
In the tower, controllers activated the crash alarm, and fire trucks immediately rushed toward the scene, whose location was marked only by the distant glow of the flames. They arrived to find a hellish field of destruction some 1,300 feet long and 130 feet wide (400 x 40 m), strewn with burning debris as far as the eye could see. Much of the DC-8 had disintegrated into unrecognizable chunks of metal, except for a few intensely burning sections of cabin. A desperate search for survivors was conducted by first responders who bravely plunged into the deadly debris field, but none were found.
Dawn broke over Gander alongside the news that all 256 people on board Arrow Air flight 1285 had perished. Hundreds of US Army families woke to the unimaginable news that their loved ones weren’t coming home, as though an irreplaceable hole had been gouged out of the heart of the 101st Airborne. And although none of the victims were Canadian, the disaster was by far the deadliest ever to occur on Canadian soil, a tragedy that would shock the country. But, as the initial shock began to fade, something more sinister started to take its place — the dark turmoil of discord.
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After airport firefighters and local emergency services, the next group of people to be notified in the immediate aftermath of an accident are air crash investigators. In the United States since 1967, such calls have gone to the National Transportation Safety Board, who were invited to assist with the Arrow Air disaster due to the involvement of a US-manufactured aircraft registered to a US airline. But the leading role in the investigation went to Canada’s equivalent agency, the Canadian Aviation Safety Board, which was considerably newer.
The CASB was created less than two years before the Arrow Air crash, in 1984, on the advice of a royal commission of inquiry into alleged mishandling of several previous investigations. Prior to that year, air crash investigations in Canada were undertaken by a team of experts belonging to an agency called the Aviation Safety Bureau, which was part of the Canadian Air Transportation Administration within the Department of Transport (now Transport Canada). Since this department was simultaneously responsible for regulating the aviation industry, promoting its development, and investigating safety mishaps, a conflict of interest existed. The CASB was an attempt to resolve this conflict by constituting a new, independent aviation investigation body.
The CASB consisted of several dozen technical experts and career accident investigators, whose job was to “kick tin” — that is, do the dirty work of gathering and interpreting evidence. These career investigators mostly came from the original Aviation Safety Bureau, because that’s where the talent was; the hope was simply that they would be able to work more freely when employed by an independent agency. They were given great leeway to gather evidence and reported only to the Director of Investigations, who was also a trained professional. The Director of Investigations in turn reported to the Board itself, whose members were political appointees. The exact role of the Board was never entirely agreed upon by its members, a problem that will be discussed in more detail later, but in general their job was to conduct administrative duties, draft probable cause statements, and put their signatures on final reports. The National Transportation Safety Board in the United States similarly has a politically appointed Board overseeing a body of professional investigators, although in practice, NTSB Board members are not appointed for their politics, and the same members are almost always reappointed from one presidential administration to the next.
The professionalism and impartiality of the NTSB have been demonstrated over the course of more than five decades of investigations, but when the Canadian CASB received the dreaded phone call on the morning of December 12th, 1985, the agency was completely untested. Its very first major case was to be nothing less than the deadliest crash on Canadian soil.
Aware of the magnitude of the challenge that faced them, a large team of technical experts and investigators assembled and deployed to the scene within 24 hours, where the painstaking process of gathering evidence began. Together with representatives of all the interested parties — the US Army, Arrow Air, McDonnell Douglas, and so on — they examined the wreckage for clues, conducted simulations, analyzed the flight recorder data, and carried out dozens of interviews. What follows is the fruit of their analysis — the story of flight 1285 that they would later submit to the Board in their draft final report.
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Judging by eyewitness accounts and the location of the wreckage, it was evident to investigators that they were dealing with what might be formally termed a “failure to gain altitude on takeoff.” Witnesses broadly agreed that the airplane never got much higher than the treetops beyond the end of the runway. Furthermore, by analyzing the pattern of trees struck by the aircraft, they were able to show that the plane impacted the forest with a 9-degree nose up pitch attitude, a 7-degree right bank, a 10-degree rightward yaw, and a downward flight path of minus 12 degrees. The fact that the plane was pitched 9 degrees up while descending on a 12-degree flight path was significant, because it meant that the airplane’s angle of attack at impact — that is, the angle between the wings and the oncoming air — was about 21 degrees, which is well above the DC-8’s stall threshold.
A stall would explain why the airplane was unable to climb after takeoff. Fundamentally, an aircraft must generate enough lift on takeoff to counteract its weight and propel it upwards. This lift comes from both airspeed and angle of attack, but if the angle of attack is too high the airplane will suffer first from excess drag, and then above a specific threshold, a stall, in which lift decreases abruptly. This process is characterized by heavy buffeting and, in swept-wing aircraft like the DC-8, a loss of directional stability. Needless to say, however, a DC-8 doesn’t stall on takeoff for no reason, because the angle of attack used for the initial climb should be well below the stall threshold as long as sufficient airspeed can be achieved.
In order to understand more about the performance of the aircraft during the DC-8’s brief flight, investigators recovered and read out the cockpit voice recorder and flight data recorder, both of which survived the accident. Unfortunately, however, they had little to work with. The cockpit voice recorder suffered an unknown malfunction that left only faint, indecipherable traces of conversation on the tape, and it was impossible to determine what was said, or whether the recording was even from flight 1285. At the same time, the flight data recorder turned out to be a primitive model, installed when the aircraft was first manufactured, which recorded airspeed, heading, altitude, vertical acceleration, and time into a rotating spool of foil. The recorder was not capable of recording any information about important factors like pitch attitude, engine power, or pilot control inputs. And to make matters worse, the vertical acceleration stylus was out of sync with the time parameter, making it difficult to pinpoint recorded acceleration changes on the timeline of events with any specificity.
In order to get anything useful out of the recorded data, investigators had to convert the stylus marks into engineering units, calibrate the results according to the recorder’s bench test history, and straighten out the vertical acceleration data to the extent possible. Careful analysis of the results yielded a few conclusions about the aircraft’s performance.
According to the data, flight 1285 lifted off the ground 51 seconds into the takeoff roll, at an airspeed of 167 knots. Airspeed continued to increase for a few seconds until it reached a maximum of 172 knots, only to begin decreasing, reaching 163 knots after ten seconds, and 140 knots at impact. Furthermore, by integrating airspeed with respect to time and accounting for wind, it was found that the DC-8 required 8,000 feet of runway in order to become airborne. Notably, this meant that liftoff occurred farther down the runway and at a higher airspeed than would be expected with the accident airplane’s recorded weight and configuration.
The load sheet for flight 1285, a copy of which was retained at the airport, indicated a gross aircraft weight of 330,625 pounds (150,000 kg). However, if the aircraft’s actual weight was considerably above this, there would have been a corresponding performance penalty, which could explain the extended takeoff roll. And as it turned out, there was plenty of reason to believe that the weight on the load sheet was a substantial underestimation.
First of all, diving into Arrow Air’s documentation, it was found that the standard empty weight of the aircraft was about 1,000 lbs (450 kg) too low because the figure failed to include removable cabin and galley equipment and the aircraft’s potable water supply. That by itself would have had no significant impact on takeoff performance, but this discrepancy was only the beginning.
Another issue that caught investigators’ eyes was the weight of the soldiers’ checked baggage. Interviews with Multinational Force and Observers (MFO) personnel who loaded the bags revealed that the passengers brought a total of 481 duffel bags and 48 foot lockers with an average weight of 70 lbs (32 kg) each, for a total of 27,950 lbs (12,680 kg). Although great effort was taken to load these bags onto the airplane during the ground stop in Cairo, not all of them were able to fit, and 41 duffel bags weighing 2,870 lbs (1,302 kg) were left behind, resulting in a total baggage weight of 25,080 lbs (11,380 kg). On top of this, 1,300 lbs (590 kg) of catering equipment and aircraft spares were also added to the cargo hold, for a gross cargo weight of 26,380 lbs (11,970 kg). However, the load sheet only indicated 25,430 lbs (11,530 kg) of cargo, an underestimate of about 1,000 lbs. That was strike two.
By far the biggest discrepancy, however, was in the weight of the passengers and their carry-on baggage. Arrow Air used an average weight of 170 lbs (77 kg) per passenger, a figure that assumed a personal weight of 165 lbs and 5 lbs of hand baggage. The airline’s weight and balance manual suggested weighing the passengers and their bags if there was any reason to believe that they might diverge significantly from this average, but the manual contained no information about how actual weights were supposed to be obtained. In this case, it was not clear that obtaining real weights would have been possible, and in fact the average weights were clearly used because the passenger and carry-on baggage weight indicated on the load sheet was 42,500 lbs (19,280 kg), which was equal to 170 pounds times 250 passengers. (The fact that two passengers did not board the airplane was apparently not accounted for.)
Investigators found that the passengers and their bags were weighed when they originally left for their deployment in the Sinai. At that time, the average personal weight of the passengers was 164 lbs (74 kg), right in line with Arrow Air’s estimate. However, each soldier carried standard-issue gear that included a gun, miscellaneous equipment, and a web belt, plus clothing, personal items, and souvenirs, with an average weight of no less than 55 lbs (24 kg) per person. Therefore, the actual weight of each passenger including carry-on baggage was 219 lbs (99 kg), not 170, and furthermore, many personnel were bringing back new souvenirs and Christmas gifts that would have raised the average even further. Thus, assuming a conservative average weight of 220 lbs per person, the real passenger and carry-on baggage weight aboard the flight should have been 54,560 lbs (24,750 kg), which was 12,000 lbs more than the amount indicated on the load sheet. Adding the 1,000 extra pounds of checked baggage and the 1,000 pounds of water and galley equipment, investigators concluded that the load sheet likely underestimated the actual weight of the airplane by about 14,000 pounds (6,350 kg), for a real gross weight of 344,450 lbs (156,240 kg).
While this discrepancy was significant, it could not by itself explain the accident. The calculated real weight of the aircraft was still under the maximum takeoff weight by a healthy margin, and the airplane should have had no trouble becoming airborne. However, if the pilots calculated their takeoff performance using a weight that was 14,000 lbs too low, then they could have used the wrong takeoff speeds, which would potentially have had some impact.
The first officer and flight engineer who flew the DC-8’s first leg from Cairo to Cologne testified that they knew the official weight was an underestimate, and that they added 10,000 lbs to their gross weight for the purposes of calculating takeoff speeds. (The captain of that flight denied this.) However, they made no remark about this decision to the accident flight crew, nor did they modify the load sheet in any way. It was therefore likely that the crew of flight 1285 were unaware of this unrecorded excess weight.
Prior to takeoff, the flight crew normally calculates several benchmark airspeeds, colloquially known as V-speeds, based on gross weight, altitude, temperature, and other parameters. For the purposes of this story, the most important V-speed is VR, or rotation speed — the speed at which the non-flying pilot will call “rotate,” prompting the flying pilot to raise the nose for liftoff.
Using the standard V-speed tables and the gross weight indicated on the load sheet, the crew would have arrived at a VR of 150 knots. However, if the calculated real weight were used, VR would have been 154 knots. When rotation is initiated too early — even as little as four knots too early — a performance penalty occurs, because at a lower speed, a higher angle of attack is needed to generate a given amount of lift. (At a higher speed, a lower angle of attack is needed, conversely.) However, the DC-8 is what’s known as “geometrically limited” — that is, it’s not possible to pitch up more than 8.6 degrees while on the ground, because the tail will strike the runway. Therefore, to become airborne at a lower speed requires a higher angle of attack, but a higher angle of attack can’t be achieved because of the aircraft’s geometric limitation. This means that liftoff will only occur once the airplane accelerates to an airspeed sufficient to generate the required lift at the fixed takeoff angle of attack,* regardless of when rotation is initiated. However, lifting the nose before sufficient speed has been achieved results in more of the fuselage being presented to the oncoming air as the plane rolls across the ground, resulting in increased drag that extends the takeoff distance and increases the speed required for liftoff.
*Note: On the ground, pitch angle is equal to AOA.
Considering the above, McDonnell Douglas calculated that if takeoff was attempted at the aircraft’s actual weight but with a VR of 150 knots, it should have taken the aircraft 47 seconds to become airborne, after consuming 6,700 feet of runway. However, flight 1285 still required 4 seconds and 1,300 feet more than this estimate.
In order to better understand this discrepancy, investigators needed to know what V-speeds the accident flight crew actually used. Without the cockpit voice recorder, the only way to do so was to determine the positions of the airspeed “bugs” on the pilots’ airspeed indicators. A “bug” is a small marker on the instrument that can be manually set to mark a desired value for further reference, including but not limited to V-speeds like VR. Examining the instruments for witness marks left by contact between the bugs and the instrument face during impact deceleration is a common “tin-kicking” technique that dates back to before the days of flight recorders.
Upon recovering the pilots’ airspeed indicators from the wreckage, investigators tentatively observed that the three bugs belonging to First Officer Connelly, who was flying the plane at the time of the accident, corresponded to values of 144, 185, and 158 knots. The latter of these, which was found on an internal bug built into the inside of the instrument, was considered the least likely to have moved during the accident, and thus the most reliable. Cross-referencing the table of V-speeds, the value of 158 knots corresponded to V2 — takeoff safety speed in the event of an engine failure — for an aircraft gross weight of 310,000 pounds (140,600 kg). Furthermore, if this weight were used, VR would have been 144 knots, which was the value shown on one of Connelly’s other bugs. This raised the possibility that the pilots used a gross weight that was almost 35,000 lbs too low, but investigators were unable to find any reason why this might have happened. Furthermore, one of Captain Griffin’s airspeed bugs was recovered with a setting close to the climb-out speed for the weight indicated on the load sheet. In the end, therefore, investigators were unable to determine whether the flight crew used the load sheet weight, or a weight that was considerably lower.
In the end, regardless of whether the crew used a VR speed of 150 or 144 knots, the evidence suggested that they probably began rotating sooner than optimal. And if they did so, then the extra drag from the higher angle of attack at liftoff would have had one more key effect: a reduced margin above the stall speed.
The stall speed is the airspeed at which the critical (or stall) angle of attack will be reached under a given set of conditions, taking into account the fact that AOA and airspeed have an inverse relationship when lift is constant. During a normal takeoff, the accident DC-8 should have achieved a climb-out speed 18 knots above the stall speed. If rotation was commenced 4 knots too early, this margin would have been reduced by about 3 knots due to the extra drag as the plane rolled across the ground with its nose in the air. And if rotation began 10 knots too early, the margin would have been reduced by about 8 knots. This should still have left plenty of margin with which to climb away safely. However, given that the airplane clearly stalled, something else must have brought the stall margin the rest of the way to zero.
One strong possibility was that the aircraft suffered some kind of mechanical failure that affected its pitch control or its ability to maintain airspeed. After all, the aging DC-8 was thought to have several major defects, including a hydraulic leak, a “ratcheting” sensation in the first officer’s control column, high temperatures in engine 4, and a flickering thrust reverser unlock light, among other items, most of which were not properly recorded in the technical log. But since the flight data recorder didn’t contain any record of system functionality, as a modern recorder would, the investigators were once again forced to gather evidence the hard way — by kicking tin.
The first and most crucial discovery, following a painstaking search of the entire flight path, was that no part of the airplane came off before the first contact with trees. It was apparent that the DC-8 was structurally intact when it hit the ground.
Next, investigators observed that the landing gear was extended at impact. Normally the pilots would retract the gear as soon as the monitoring pilot sees the altitude increasing and calls “positive rate, gear up.” The fact that this was not done reinforced the statements of witnesses, including that of the controller, who reported that the airplane gained little to no altitude after takeoff. In all likelihood, the pilots never saw a positive climb rate, never called gear up, and spent the rest of their brief flight trying to control the airplane first and foremost.
One reason why an airplane might not gain altitude is if the flaps, which increase lift, were not extended for takeoff. However, upon examining recovered portions of the flap mechanisms, investigators noted that all of them bore impact markings consistent with the flaps having been extended during the crash. That was not to say that the markings were consistent with each other: in fact, the derived flap positions on various actuators ranged anywhere between 18 and 50 degrees of extension. These included impossible contradictory readings on opposite sides of the same flap track, suggesting that the impact markings were not an especially reliable means of determining where exactly the flaps were positioned. Nevertheless, no evidence was found of any pre-impact mechanical failure of any of the flaps. Most likely, the flaps were subjected to unpredictable forces during breakup of the aircraft, causing the diverse witness marks. But in any case there was no doubt that they were extended sufficiently to enable the takeoff.
In contrast, the largest area of concern was the engines. The failure of one or more engines could explain some or all of the difference between flight 1285’s expected and actual performance.
All four of the DC-8’s engines were found badly damaged by both impact and fire, but each contained evidence of its prior condition. Most importantly, heavy torsional damage was found on the shafts of engines 1, 2, and 3, consistent with operation at high power on impact. However, the rotational damage on engine 4 was much less severe, raising the possibility that it had failed before impact and was spooling down when the plane struck the trees. Investigators calculated that the damage on the №4 engine was consistent with impact while running at between 40 and 43% of the max RPM, which is closer to idle power than takeoff thrust. Separately, however, engine manufacturer Pratt & Whitney arrived at an impact RPM only 12–14% lower than that of the other engines, which were presumed to be at takeoff power. An independent metallurgical engineer hired in part to resolve this discrepancy concluded that the №4 engine was operating at close to maximum power when it ingested parts of trees, causing it to lose thrust. However, the question of whether this engine lost thrust before impact was never fully resolved.
As for why the №4 engine could have failed, the only lead investigators found was a ruptured pressure regulator diaphragm that may or may not have burst before the crash. It was possible that this failure, if it occurred before impact, could have resulted in too much fuel being fed to the engine. This could in turn have caused a compressor stall, in which the combustion chamber pressure exceeds the pressure in the compressor section, resulting in a reversal of airflow and an explosive surge similar to backfiring. This condition can cause loss of thrust and the appearance of flames around the engine exhaust area due to incomplete combustion of fuel. This would not have been inconsistent with witness accounts of a “glow” as the aircraft passed overhead, and some observers even positioned this glow on the right side of the aircraft, where engine 4 was located. However, only one witness thought that the glow might be fire, and some of the others thought it was just the airplane’s landing lights, or the runway approach lights reflecting off its underside. Furthermore, even if the glow was fire, a compressor stall can also be caused by high angle of attack, as the indirect airflow over the engine inlet causes a drop in compressor pressure. And since the aircraft was known to have had a high impact AOA, there was a strong possibility that any compressor stall of the №4 engine was the result of angle of attack alone, and not a pre-existing failure.
Attempts to use other indications to determine the status of the engines were inconclusive. The cockpit gauges displaying the engine pressure ratio, a facsimile for thrust, showed high thrust on engines 1, 3, and 4, and low thrust on engine 2, even though the damage to this engine indicated that it was running at high power. Furthermore, the fire extinguishers for engines 1, 2, and 4 had been discharged, and the №3 extinguisher was ambiguous. However, the extinguishers are designed to discharge automatically when exposed to high temperatures, such as a post-crash fire. Additionally, even if the pilots did have some reason to activate one or more fire extinguishers, they were trained not to do so until a safe altitude had been reached, which clearly never occurred. And as if that wasn’t enough, the nature of the damage to the engine fire warning light bulbs showed that they were not lit at impact. Numerous other warning lights were, however, illuminated, even though no pattern connecting the affected systems could be established. Investigators were inclined to believe that these lights came on during the several seconds between the first tree impact and the final impact with the ground, during which multiple systems no doubt suffered severe damage.
Due to the reports of a thrust reverser unlock light having illuminated on the Cairo-Cologne flight, investigators also examined the thrust reversers, which are used to redirect engine thrust to slow the plane on landing. However, none of the reversers displayed the witness marks that would be expected if the devices were deployed at impact. The marks that were found were consistent with the reversers having been stowed.
Lastly, investigators examined the pitch controls, but found no evidence that the elevators had jammed prior to impact, and the horizontal stabilizer was found set to the correct setting for takeoff.
In the end, investigators could not find conclusive evidence of any pre-impact mechanical failure. Although they declined to rule out the possibility that the №4 engine failed before the crash, they hesitated to rule it in either. Its status was simply left as an unknown.
Investigators also studied several mechanical failures in a simulator, and found that some of them did produce flight paths similar to the accident flight. Full reverse thrust on engine 4 and a severe flap asymmetry could both have resulted in a loss of control consistent with the FDR data. However, given the lack of physical evidence for either of these scenarios, both were discarded. Also discarded was a jammed elevator, which would have produced a different flight path; and a total loss of hydraulic fluid (due to the aforementioned leak), which would not have been catastrophic. In fact, the DC-8 is fully capable of flying with no hydraulic power at all, and witnesses testified that Captain Griffin had actually taken off in the accident aircraft on two previous occasions with no hydraulic fluid in the system, only to experience few if any negative effects.
So, if the only plausible mechanical problem was an engine failure, what effect would that have had on the takeoff performance? In the end, the simulation showed that the failure of one or even two engines at the most critical point during the takeoff was still insufficient to prevent the aircraft from climbing, even in combination with the most adverse early rotation. Therefore, some part of the puzzle was still missing. And that was when investigators began to seriously consider a culprit that was no longer present at the crash site: the weather.
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Another way of looking at the data was to assume that the gap between the expected and actual performance was due to some combination of reduced lifting ability and increased drag. Using some very complicated math, McDonnell Douglas estimated that as long as normal pilot control inputs occurred, then the only solution to the airplane’s performance equation was to assume a 30% reduction in the maximum lift coefficient generated by the wings, and a 100% increase in drag. That type of performance degradation is usually a telltale sign that the aircraft was contaminated with ice.
By 1985, the deleterious effects of even very small amounts of ice on aircraft performance were already well known, having been established by several studies dating back to the 1950s. (My previous article on Comair flight 3272 goes into the history of some of this research.) In their report on the Arrow Air crash, the investigators wrote, “Surface roughness caused by ice, frost, snow, or even large accumulations of insect debris or badly chipped paint can be sufficient to cause significant decreases in lift production and increases in drag.” Being experts in their field, it was no surprise that the investigators were aware of these effects. But at that time, many pilots and other aviation professionals were not, and some common practices were not respectful of the magnitude of the danger.
According to detailed weather observations at Gander Airport on the morning of the accident, very light freezing drizzle was falling when flight 1285 landed at 5:34. Around 6:15, the drizzle turned to scattered snow grains, which continued to fall until the accident occurred at 6:45. During this time, the weather observer routinely checked the level of ice buildup on the sheet of aircraft wing skin material outside the tower. Between 5:00 and 6:00, about 30% of the sample was covered by frozen drizzle and adhered snow grains with a rough texture that he testified was similar to “medium grit sandpaper.” These observations trailed off after 6:00, although some snow grains continued to adhere to the surface after that.
But that was only half the equation — flight 1285 also could have picked up ice on approach as it descended through the clouds. In interviews with four pilots who flew into or out of Gander around the time of the accident, two stated that they didn’t encounter any noticeable icing, but two said they did. The pilot of a 737 who departed Gander 30 minutes before the accident reported moderate icing in cloud which resulted in the accumulation of 0.25 in (6.4 mm) of ice within one minute, although no control difficulties resulted. The pilot of a single-engine Piper who landed 30 seconds after the crash also reported freezing drizzle between 4,000 and 700 feet, which was sufficient to obscure the windscreen. Furthermore, a refueling technician who entered the cockpit of flight 1285 while it was on the ground said that Flight Engineer Fowler mentioned picking up a little ice on approach, and a small amount of ice was visible around the corners of the windscreen.
Using existing models of ice accumulation and weather service data about the atmospheric conditions at Gander that morning, the CASB calculated that the DC-8 likely encountered supercooled droplets that would have impacted the wing leading edges and then slid back before freezing, resulting in a chaotic distribution of ice across a large portion of the wing. This could have resulted in a maximum ice accretion of between 0.34 in (8.7 mm) and 0.20 in (5.0 mm) depending on the distance from the leading edge. This would have been reduced if the pilots had used their airframe de-icing equipment, but other Arrow Air pilots testified that it would have been unusual to turn on de-icing in conditions like those at Gander on the day of the accident. This was consistent with the prevailing wisdom of the time, which was to turn on de-icing equipment only when a significant amount of ice became visible to the naked eye. In practice, this often meant a half an inch or more.
After landing, even more ice would have built up due to the freezing drizzle that fell while the plane was on the ground. Despite this, the crew did not ask to de-ice, and in fact out of three other aircraft on the ground in Gander at that time, only one elected to do so. In all likelihood, the pilots didn’t consider the small amount of ice around their windscreen to be indicative of any particular danger, and they would hardly have been alone in this estimation. However, it was not possible to positively determine how much ice was actually present, because none of the ground personnel who worked on the plane recalled checking for ice. Furthermore, the stopover occurred under conditions of darkness, and the top of the wing was not visible, so the probability of detecting ice was not high, even if they did look. Modern regulations require that pilots or ground personnel physically touch the upper wing surface to identify nearly invisible clear ice, but this was not the practice in 1985.
The danger posed by the type of rough, sandpaper-like ice described by the weather observer is that it reduces the angle of attack at which the airplane will stall. A stall normally occurs when the AOA becomes too high for air to flow smoothly over the tops of the wings, resulting in “separation” of the airflow, accompanied by localized turbulence and heavy buffeting. But if the top of the wing isn’t smooth, this separation will occur earlier — that is, at a lower angle of attack. Only a very small amount of roughness is needed to produce this effect, especially on aircraft that lack leading edge slats, such as the DC-8. In fact, according to McDonnell Douglas, only 0.04 in (1 mm) of rough ice on the DC-8 will result in a 25% reduction in the maximum lift coefficient attainable before airflow separation occurs. Furthermore, ice also decreases the amount of lift produced at any given AOA, and therefore, for any given airspeed, a higher AOA is needed to generate the expected amount of lift. This higher AOA presents more of the fuselage to the oncoming air, resulting in greater drag in addition to the reduced lift. The drag in turn causes the aircraft to slow down, again forcing the AOA to increase further in order to maintain lift. Therefore, not only does ice reduce the stall AOA, it also reduces the ability of the aircraft to take off and climb normally without exceeding said AOA.
And as if that wasn’t bad enough, the stall warning systems on airliners are calibrated based on the expected stall AOA on a “clean” wing with no ice. The warning systems don’t “know” that the stall AOA has been reduced by ice, and as a result the warnings may activate only a split second before the stall occurs, or not at all. And on top of that, the DC-8 becomes very touchy in the pitch axis when ice contamination is present, making it easy to overcontrol the aircraft; little or no pitch up control force may be needed to result in a significant AOA increase.
All of these effects therefore combine to make the DC-8 intensely vulnerable to small amounts of wing surface roughness. And given the evidence that such ice was in fact present, investigators developed a model to determine whether the effects of that ice could explain the behavior of the accident aircraft.
The results of the simulations showed, first of all, that regardless of whether the pilots rotated early or whether any engines failed, ice contamination was necessary to produce a flight path resembling the accident. Assuming an early rotation, the scenarios that most closely matched the accident flight path were 0.02 in (0.5 mm) of contamination with the failure of engine 4, and 0.04 in (1 mm) of contamination with or without an engine failure. Both of these contamination levels were well under the maximum predicted by the weather model.
With 1 mm of ice present, a stall would occur at 11.7 degrees AOA, which was below the normal takeoff pitch attitude of 12.5 degrees. The airplane would have become airborne because it was geometrically limited to 8.6 degrees pitch up while on the ground, preventing the stall AOA from being reached prior to liftoff (again, recall that AOA = pitch attitude when on the ground). However, after liftoff the pilots would have continued rotating to 12.5 degrees pitch. Normally the AOA remains low throughout this maneuver, because the pilots only begin rotating once sufficient speed for liftoff has already been achieved, and once airborne the AOA should remain low as the airplane assumes a climbing trajectory (recall: if the plane is climbing at a similar gradient to its pitch angle, the AOA will be low). But in this case, with the presumed early rotation, the nose would have come up before the plane was ready to lift off, resulting in an increased AOA on the ground. This would have resulted in greater drag, making it harder to accelerate. Then, once in the air, the rotation to 12.5 degrees would not have produced the expected climbing flight path because the ice was reducing the amount of lift generated by the wings. If the pilots sensed that the plane was not climbing normally, they might have tried pitching up more, in the assumption that a higher AOA would generate more lift. But a higher AOA also causes more drag, requiring more thrust in order to maintain airspeed. Since the AOA was already unusually high, this further increase would have left the plane with more drag than thrust, causing airspeed to decrease. This was why the airspeed peaked at 172 knots three seconds after liftoff. Thereafter, the speed would have continued to decrease, and the AOA would have continued to increase to compensate, until the reduced stall AOA of 11.7 degrees was reached, at which point the aircraft stalled. The pilots likely would not have received any kind of stall warning.
The exact timing of the stall was uncertain, but investigators believed it occurred within 10 seconds of liftoff, during which time the aircraft gained no more than 125 feet of altitude. After that point, wild fluctuations were observed in the recorded altitude trace, well beyond the actual capabilities of the aircraft. This was likely due to fluctuations in measured air pressure caused by stall buffeting affecting the static ports. These fluctuations continued until the aircraft struck the forest, with an AOA at impact of 21 degrees. The pilots likely tried to pull up in order to avoid hitting the ground, but with the aircraft in a stalled state, this would only have increased the AOA even more, without modifying the flight path. And even if they had recognized the problem and tried to reduce the AOA instead, there was insufficient altitude to recover.
In the CASB investigators’ view, then, the evidence was not so strong as to completely preclude other possibilities, but the probability favored a combination of factors that conspired to prevent flight 1285 from climbing — first, the early rotation due to the underestimated weight, which reduced the stall margin; and second, the accumulation of ice, which reduced the stall margin further, until the angle of attack needed in order to climb became greater than the stall AOA. A failure of engine 4, if it occurred, could have exacerbated the situation still further. In either case, within seconds, recovery would have been impossible.
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Despite the above, the involvement of military personnel who had been deployed on a sensitive operation, and the possible carriage of weapons on board the plane, led investigators to take a close look at the possibility of sabotage or an accidental explosion, which was addressed in the CASB’s report.
Initial suspicions were raised in part due to a claim of responsibility by the militant group Islamic Jihad, who opposed the peace agreement between Egypt and Israel. It was unclear how the group could have sabotaged the airplane, however, so this claim was dismissed as opportunistic in the absence of evidence of their involvement.
The biggest proponents of the explosion theory were Arrow Air themselves. The company was not receptive to lines of investigation that suggested any possibility of fault, and consultants hired by the airline repeatedly sought evidence of an on-board explosion. Early in the investigation, one consultant pointed out multiple pieces of fuselage skin containing holes with outward “petaling,” which they claimed were indicative of a pressure spike within the aircraft, perhaps an explosion. However, while outward curling metal is popularly imagined to be a telltale mark of a blast, this is only true when found in conjunction with other, much more positive evidence. Such evidence was not found, as the RCMP Central Forensic Laboratory examined the specified pieces of debris and identified no foreign material or explosive residue on them. Experienced investigators were not surprised by this finding because outward curling metal debris is frequently found in plane crashes due to the myriad forces involved. Such holes in fuselage panels are usually created when an interior object is forced outward through the skin during impact.
The CASB also ruled out the possibility that munitions were carried on board. They did find plenty of weapons, including 25 pistols, 202 M16s, 24 M203s, two M60s, and one unidentified “rifle,” as well as several inert explosives training devices. None of the weapons were loaded. This corresponded well to the official manifest, which mentioned similar weapons. The only ammunition known to be on board was a single clip of .45 caliber bullets, which was not recovered. No explosives were identified in the wreckage.
The fact that no debris was found before the initial impact point was also strong evidence against the explosion theory. Nevertheless, the same consultant for Arrow Air claimed that pieces of the forward fuselage had been blown off in flight and ingested into the №3 engine, causing it to fail. This analysis was based on orange paint transfer markings on the №3 inlet guide vanes, which CASB investigators pointed out were present on all four engines and perfectly matched the color of the front-end loader used to recover the engines from the crash site.
Perhaps the most contentious point, however, was the autopsy of the victims. Witness accounts of a glow as the airplane passed overhead led to speculation about a fire in flight, which could have left evidence in the form of inhaled smoke in the victims’ tracheas. Although the flight only lasted about 20 seconds, it was theoretically possible that an explosion within the cabin, perhaps due to improperly carried ordnance, would have produced enough smoke in that time to be detectable in the victims post-mortem. And lo and behold, 39 of the victims had in fact inhaled smoke prior to death, based on soot deposits in their airways. Quite a lot more victims had detectable levels of carbon monoxide and hydrogen cyanide in their blood, but these chemicals can enter the bloodstream through open chest wounds after death, so soot in the trachea was considered a more definitive indicator of smoke inhalation.
The question, then, was whether these 39 victims inhaled smoke before or after the crash. After all, smoke was plentiful after the airplane hit the ground, but if these passengers died instantly, then the smoke could only have entered their airways prior to impact. To answer this question, investigators hired medical experts to examine the injuries sustained by each victim and make a morbid measurement not usually pursued in air crashes — that is, how long it actually took for them to die. This analysis showed that 41 victims would have died instantly; 51 would have died within 30 seconds; and 158 would have died between 30 seconds and five minutes. Of the aforementioned group of 39 victims, all but one were in the “30 seconds to five minutes” category, and none died instantly. This was consistent with the autopsy results, which showed that 31 victims died solely due to the effects of fire and smoke, and another 41 died due to both combustion products and impact injuries, proving that some people did briefly survive only to die in the fire. While this finding couldn’t prove that there wasn’t an in-flight fire, it did show that the observed evidence was consistent with the assumption that no in-flight fire occurred.
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Although debate is commonplace during investigations, it’s the investigators’ job to examine each hypothesis on its merits and choose the one that best fits the evidence, which is what the CASB did. The available evidence was scant, but it was enough to point them in the direction of what may have happened — and to rule out what did not. And so, the CASB staff wrote up a report containing all the above information and submitted it to the Board for determination of a probable cause statement. And that’s where we get to the other half of this story.
The seeds of the conflict that would come to envelop the Arrow Air investigation had their origins in 1984, when the CASB was created. At that time, the Liberal Party was in power under Pierre Trudeau, but the scandal-ridden Prime Minister resigned later that summer. In a brazen parting act, Trudeau attempted to cement his legacy by handing out hundreds of “patronage appointments” to people with party connections. Among the positions handed out were two spots on the board of the newly minted CASB, which went to Trudeau’s speechwriter William MacEachern and Liberal MP Arthur Portelance. This pair joined the four existing Board members, consisting of lawyer Bernard Deschênes (the Board Chairman), retired Air Canada pilot Roderick Stevenson, retired Brigadier General Roger Lacroix, and retired aircraft engineer Frank Thurston. Although most of these Board members didn’t have aviation experience, that’s not unusual, or even undesirable, as long as the purpose of the Board is simply to perform administrative duties and put signatures on the conclusions reached by the professional investigators.
In the United States, the National Transportation Safety Board is limited to five members, and at the time of this writing it has only three. But the CASB charter didn’t include any limit, and after Brian Mulroney’s Progressive Conservative Party won the election of 1984, he decided to “balance” the board’s political leanings by making some appointments of his own in 1985. The new appointees included former Air Force pilot and flight instructor Bruce Pultz, and aeronautical engineers Norman Bobbitt and David Mussallem. These appointments expanded the Board to nine members, with the unintended consequence that the body was now large enough to develop internal factions. And the seed for this division was planted in the CASB’s charter itself, which failed to clearly explain what, exactly, the Board members do.
According to investigative reporting by Carol Goar for the Toronto Star, a subgroup quickly developed within the Board, consisting of members Stevenson, Bobbitt, and Lacroix. Each was fueled in part by dissatisfaction with the notion that their job, as Deschênes envisioned it, was to sign off on probable cause statements, and not to “kick tin,” which is probably what they really wanted to do. Bobbitt had even applied to be a professional crash investigator, but was rejected. Stevenson, meanwhile, was disliked by the investigators for his “habit of going out to crash sites and ordering the investigators around, which they [found] irritating” (Goar, Toronto Star, 23 March 1989). Lacroix, for his part, was fueled by his envy of Chairman Deschênes, whose position he wanted, and perhaps by something more esoteric as well: “From time to time, he consults psychics about airline crashes, which unsettles his colleagues,” Goar wrote (Ibid).
These problems only continued when the CASB launched its investigation into the Arrow Air crash in December 1985. But it took one more year and another appointment to the Board before the internal conflict truly spiraled out of control.
In December 1986 or January 1987 (sources disagree), the transport minister appointed aeronautical engineer Les Filotas as the tenth member of the CASB. Filotas was a self-acknowledged patronage appointment who got his position because he was friends with the fisheries minister. Like Bobbitt, he had also tried to apply for a position as a career investigator, but was rejected.
According to Goar with the Toronto Star, Filotas made enemies straightaway when he walked into Chairman Deschênes’ office on day one of his tenure and announced that he expected to “see a lot of changes in the way the board operates” (Ibid). He strongly believed that his position on the Board should allow him to influence investigations and he was unhappy with the notion that he was to act as a “rubber stamp” on whatever the professional investigators felt was the cause of an accident. This position struck a chord with Bobbitt, Stevenson, and Lacroix, who soon joined forces behind Filotas in a concerted push to undermine the power of Chairman Deschênes and increase the Board’s investigative power. This didn’t sit well with the career investigators, who felt responsible only to Tom Hinton, the Director of Investigations, and not to the Board members. This perceived animosity from a minority of the Board severely damaged morale among the CASB personnel, prompting several senior investigators to leave the agency.
By the summer of 1987, the dispute had become so bitter that an internal review of the Board’s functioning was commissioned. This report concluded that, “A disruptive group has gone to excessive lengths to force their will on the board… The divisions are so entrenched that, if allowed to continue, the board’s effectiveness could be seriously impaired” (Goar, Toronto Star, 23 March 1989). In response, Mulroney’s government raised the possibility of scrapping the CASB altogether and replacing it with a new agency possessing a clearer mandate and a more amenable Board. This was unacceptable to the Board’s dissident clique, who responded by threatening to challenge the government in court over what was in their view the failure of the Board’s leadership to do its job by scrutinizing the work of the investigators. The Transport Minister bowed to the pressure by agreeing to allow a competing review by a lawyer from a law firm hired by the dissident group. Predictably, this new review characterized Filotas, Bobbitt, Stevenson, and Lacroix as “reformers who feel powerless to carry out their mandate” (Ibid). Deschênes was subsequently replaced as chairman by retired Air Force General Kenneth Thorneycroft in an attempt to smooth over relations, but Thorneycroft gave the dissident group no quarter either. Meanwhile, the effort to scrap the CASB went into parliamentary limbo, and the status quo persisted.
On the ground, the Arrow Air investigation dragged on. Relations between the career investigators and the dissident Board members were already poor due to their differences about how investigations should be run, and that conflict seeped into the Arrow Air inquiry. The dissident group was mistrustful of the professionals and began to feel that someone was trying to pull the wool over their eyes. Hinton, the Director of Investigations, later described these Board members’ behavior as “abusive,” citing “very close and aggressive questioning, so intensive and aggressive that it appears to challenge the integrity of the investigator being questioned” (Koring, The Globe and Mail, 14 January 1989). Member Stevenson had a very different take on the matter. “We are trying to get at the truth,” he said. “It’s not abuse when people are arrogantly defiant and willful. We have been frustrated and thwarted in our efforts to learn what’s really going on” (Ibid).
This situation highlights the dangers of mutual mistrust. In all probability, neither side was hiding anything. But the career investigators likely saw the Board members as outsiders, not experts in crash investigations, who had their own agendas and were not worth taking seriously. This dismissiveness might have been read as deceitfulness, at which point the Board dissidents would have felt that they needed to be even more aggressive in order to pry out some hidden truth that the investigators were hiding. As for what was “really going on,” it probably wasn’t anything out of the ordinary. But in a climate of hostility, everyone becomes suspect.
As 1987 drew to a close, the Arrow Air investigation neared its end, and the investigators submitted their draft report to the Board. The report concluded that the cause of the accident could not be established beyond doubt, but that ice on the wings was the most likely reason, with incorrect takeoff speeds and a possible failure of engine 4 as potentially contributing factors. Board Chairman Thorneycroft and Members MacEachern, Portelance, Pultz, and Thurston were prepared to accept this conclusion, but Members Filotas, Stevenson, Bobbitt, Musallem, and Lacroix were not. When it nevertheless became clear that the Chairman would accept the investigators’ findings over the dissidents’ protests, Lacroix resigned from the Board, while the four remaining dissenters sat down to pen what would become a shambolic minority report on the accident that has clouded the waters ever since.
The minority report is only 14 pages long, minus appendices, compared to the majority report’s healthy 95. It is light on facts, heavy on assumptions, and falls into almost every logical pitfall that real investigators are trained to avoid.
The report opens by criticizing the majority conclusion as a case of “blaming the pilots,” upon whom praise is heaped for their professionalism and diligence, while disputing a strawman claim that fatigue was responsible for the crash. The majority report found that the pilots were likely fatigued due to duty time limit violations in the days leading up to the crash, which the minority report dismisses, claiming that the pilots couldn’t have been tired because they had “only” flown 6 hours that day and had plenty of time off in November. The fact that the majority report did not actually find grounds to connect fatigue to the accident is not mentioned by the minority.
Next, the minority report dismisses the possibility that the crew used V-speeds that were too low, citing the unreliability of the post-crash positions of the pilots’ airspeed bugs. While these positions were indeed unreliable, there remains no evidence that the flight crew was aware that the plane was 14,000 pounds heavier than the load sheet. Such knowledge would have been required in order to use the correct speeds.
The minority report then attacks the idea of ice on the wings as “theoretical,” writing that the only direct attestation of ice was the flight engineer’s comment about picking up some ice on approach. The specific words used were that the ice “wasn’t too bad, there’s a tiny bit around the left window.” The report argues that this comment showed the crew were aware of the ice, were aware that there was no dangerous ice on the wings, and had used the de-icing equipment during the approach. No evidence for these massive logical leaps is provided and it’s unclear how such conclusions could be drawn from the flight engineer’s comment. Furthermore, this entire argument is contrary to the way ice is normally examined as a factor in aircraft accidents. By definition, the crew of an aircraft that crashed on takeoff due to ice contamination is unlikely to have known the real extent of the contamination beforehand, or else they wouldn’t have crashed. For that reason, the quantity and type of ice that may have been on an airplane is always derived from performance analysis and meteorological models, not witness statements. The presence of ice in this case was attested by these methods, which were in line with standard investigative practice both then and now.
After that, the minority report claims that Captain Griffin would not have taken off with ice on his wings, and that accusing him of doing so was at odds with his record of diligence. This statement completely misses the point of the majority’s conclusion, which was that the pilots would have believed the wings to be free of ice, and that the industry as a whole was underestimating the danger. Today, it’s known that the only way to reliably detect clear ice on the wings is to physically touch them, which was not the practice at the time, was not done, and would not even have occurred to this flight crew, or any flight crew. The investigators were in fact quite concerned that airplanes could be taking off with similar amounts of ice all the time without anyone knowing. The idea that this amounts to “blaming the pilot” is ludicrous.
The minority report also tries to argue against the notion that flight 1285 experienced a stall (“The Aircraft Did Not Stall,” reads the title of section 3.2). To support this position, the report states that the altitude fluctuations after takeoff were not caused by stall buffet but were actually present on every previous heavy takeoff in this aircraft. The data to support this assertion are not provided. The report also claims that the measured AOA at impact could be in error by up to 6 degrees, and that it would have been affected by the pilots’ efforts to pull up to avoid the ground. (Nevertheless, an AOA 6 degrees below that measured would still have been well above the calculated stall AOA with ice on the wings.)
Fundamentally, the minority report fails to rebut the assertion that the airplane stalled, because it doesn’t address the primary stall indicators. Investigators believed the airplane stalled because it failed to gain altitude after takeoff while simultaneously losing airspeed. These are classic symptoms of an inability to produce adequate lift, which at the end of the day is what makes a stall a stall.
The report also dismisses the lift and drag calculations, writing that it’s not believable that “minute amounts of ‘equivalent roughness’ [could] overpower all four engines at takeoff power.” In their view, the calculated drag values were much too high because the investigators extrapolated a function exponentially without sufficient experimental backing. However, the disastrous effects of tiny amounts of rough ice are well established today, and frankly they were well established at that time, too, even though many in the industry were yet to listen. Many airliners have crashed, at the cost of hundreds of lives, due to ice buildups not dissimilar to the one that likely affected flight 1285. And to that I want to add that the report’s incredulity is based on an incorrect understanding of what ice contamination does: it does not “overpower” the thrust from all four engines at takeoff power. No matter how much power the engines are producing, the airplane will stall if the AOA required to climb at the requested rate is greater than the stall AOA.
Continuing its argument, the minority report states that the only way to replicate the accident flight path following a stall in the first ten seconds after liftoff is to assume that the pilots raised the nose to 18 degrees and held it there despite decreasing airspeed and indications of a stall. No specific evidence for this claim is provided. Even if this was the case, however, the report argues that the pilots would not have done this, which is an untested and potentially dubious claim. It was unlikely that the stall warning went off until just before impact, and the airspeed would have appeared to remain well above the normal stall speed throughout the flight. Furthermore, raising the nose can be an instinctive reaction in response to the failure to climb immediately following liftoff, as has been demonstrated repeatedly in numerous accidents. It would also have been easy to overcontrol due to the sensitivity of the DC-8’s pitch controls when the wings are contaminated with ice, and the pilots would have experienced an intense reluctance to pitch down given their proximity to the ground. To state these facts hardly besmirches the crew’s reputation; in fact, I think most flight crews in their position would have done the same.
Instead of acknowledging these facts, however, the minority report claims that the best fit for the accident flight path is a simultaneous failure of all four engines shortly after liftoff, which prompted the flight crew to lower the nose in a futile effort to maintain airspeed. This is obviously a huge claim requiring solid evidence. The report makes some attempt to provide evidence that the engines were not running above idle power at impact, although this evidence is far from convincing — for example, it relies in part on the assertion that the trees ingested by the engines during the crash weren’t big enough to cause the observed damage, which makes one wonder whether the dissenters had ever seen what happens when a jet engine sucks in a tree. The report also highlights two witnesses who said they didn’t hear any engine noise as the plane passed overhead, even though witness accounts of engine sounds are notoriously unreliable.
Probably the most interesting point made by the report is that the discrepancy between the manufacturer’s estimate of the №4 engine’s speed at impact (12–14% below the other engines) and the CASB’s estimate (40–43% of max thrust) could be reconciled if one assumed all the engines were operating at low power. However, the physical evidence didn’t provide any strong evidence in favor of this theory.
The report then argues that the possibility that 0.03 or 0.04 in of ice on the wing would cause such a massive deceleration can be dismissed as relatively improbable when the possibility of a quadruple engine failure also exists. This makes no sense to anyone with even a passing knowledge of how rough ice affects aircraft performance. Ice contamination has caused many crashes with similar profiles to Arrow Air. Meanwhile, a quadruple engine failure on a four-engine jet is an incredibly rare event that has only happened a handful of times in the history of powered flight, almost all of them due to either fuel starvation or ingestion of volcanic ash. Obviously, neither of those was a factor here, so it should have been incumbent upon the dissenters to provide truly remarkable evidence that such an unprecedented event actually occurred. Needless to say, they did not.
Instead, the report provides an equally improbable scenario to explain its improbable conclusion. Specifically, the dissent argues that the impact witness marks on all four thrust reversers are consistent with the reversers having been deployed at impact, although the argument mainly consists of an attempt to dismiss the majority’s evidence that the reversers weren’t deployed. The report also does not attempt to explain what mechanism would cause all four reversers to deploy simultaneously, even though this event is incredibly improbable, given that each reverser is independent of the others.
The dissent’s obsession with improbable mechanical failures only continues from there. Their report argues that unreliable systems information derived from the wreckage, like the contradictory flap positions, engine instrument indications, and warning lights, shouldn’t be written off as the result of post-impact damage in a “complex accident” potentially involving “multiple failures.” As evidence of these “multiple failures,” the report points to the extended landing gear, which they claim is evidence of a hydraulic system malfunction. The basis for this claim is that the flight crew, being experienced and diligent pilots, would not have failed to retract the landing gear when faced with declining airspeed. This is a basic investigative fallacy that trained investigators would never have made. A pilot’s supposed experience and professionalism are not by themselves cause to assume that evidence of imperfect behavior must point to a malfunction. This has never been the case, it never will be the case, and any self-respecting crash investigator who presents such an argument in a final report today should probably be sacked. In this case, the far more likely explanation is that the occurrence of an emergency before the “gear up” call resulted in the omission to raise the gear, which has happened in many accidents involving pilots at all experience levels.
After spending several pages arguing for some kind of quadruple engine failure, the report then abruptly pivots back to its original argument in favor of an on-board explosion. The report discusses witness accounts at length, contradicting the majority report’s claim that only one witness reported seeing fire on the aircraft. However, anyone who has worked in the field of crash investigation should know that witnesses report fire on a stricken aircraft in many cases, regardless of whether fire was actually present. In fact, “the aircraft was on fire when it went down” is probably the single most common spurious witness report after any type of plane crash.
The ignorance of the dissenters with regards to witness reliability is again put on display only a paragraph later, when they cite witness testimony of a flash that lit up the sky several seconds before the fireball associated with impact. The report claims that this is evidence of an explosion before the plane hit the ground, but this is actually a normal observation when a plane crashes in trees. The ignition of the fire upon impact is not directly visible to observers because it’s obscured by the forest, but under conditions of darkness, the ignition will produce a flash that reflects off the clouds overhead. The fireball will then curl up above the forest several seconds later. This delayed fireball can be seen in several famous videos of crashes in forests, such as Air France flight 296 in 1988.
The report then goes on to dismiss the claim that the victims who inhaled soot could have survived the crash, wryly commenting that some of them were decapitated — without providing any evidence. Instead, the report argues that the passengers clearly inhaled smoke from a fire in the cabin before impact, which could have been caused by an explosion. The fact that none of the passengers were found to have injuries consistent with exposure to such an explosion was no matter, they wrote, because such injuries could be indistinguishable from impact injuries.
As for the source of the explosion, the report suggests a terrorist attack, claiming that lax security in Cairo could have been responsible. The report describes a chaotic and disorganized baggage loading process during which the ramp was repeatedly left in darkness, with only a single Egyptian soldier standing guard, even as fights broke out between baggage handlers. The report also points to the claim of responsibility by Islamic Jihad, despite the fact that this organization has a history of claiming attacks that they didn’t commit. The dissenters appear unaware of this, citing the 1983 Beirut barracks bombing as evidence of Islamic Jihad’s capabilities, even though a court inquiry concluded that the group wasn’t responsible for that attack either.
The report also raises the possibility that the explosion was accidental, perhaps due to munitions carried aboard the plane by soldiers as illicit souvenirs. Allegedly, there had been two previous incidents in which military charters were found to have carried ordnance in this manner. The report states that a device such as a magnesium trip-flare could have exploded, starting a fast-moving fire that would have quickly escaped the forward baggage compartment due to missing sections of the fireproof cargo liner, which were mentioned in the plane’s maintenance history. The report claims that this could have produced a glow with no visible flames, consistent with witness observations, while causing numerous malfunctions. No evidence is provided that would suggest a magnesium trip-flare was actually on board the aircraft.
Continuing its half-hearted rebuttal of the majority’s conclusions in this area, the report states that evidence of an in-flight fire could have been uncovered if a full reconstruction of the airframe had been performed. (Doing this would have made sense to those who believed that an in-flight fire was a real possibility, but the professional investigators didn’t think that was the case.) The report then dismisses the RCMP’s forensic findings, writing that the absence of explosive residue was “expected” due to the “extensive weathering” of the debris prior to testing, citing no evidence. The dissenters also claim that the outward-crumpled holes in the fuselage couldn’t have been produced by the impact without causing secondary damage that was not found, again citing no evidence. The report then mentions explosions amid the wreckage that were observed by firefighters, but does not explain why, if these explosions were caused by illegal ordnance, no such ordnance was found.
In its concluding thesis, the report claims that the evidence points to a catastrophic explosion in the underside of the aircraft that caused numerous secondary failures of the flight controls, flaps, thrust reversers, engines, and so on, resulting in widespread and unpredictable damage that rendered the aircraft uncontrollable. An argument is made that these myriad discrepancies must point to a catastrophic common event affecting many independent systems, and that an explosion is the most likely possibility. The report avoids much discussion of a well-attested common catastrophic event that definitely affected all aircraft systems, which was ground impact.
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In accordance with international best practices, the above minority report was appended to the majority report, and both were published together in November of 1988. Needless to say, the release of a split report did little to settle the Arrow Air case, and away from the crash scene the drama continued.
Before we discuss that, however, I want to step back and point out that while the minority report was clearly the brainchild of dissatisfied Board members who lacked crash investigation experience, it’s still entirely possible that its authors believed what they wrote. It has sometimes been suggested that the dissenting report was a cynical ploy intended to advance Les Filotas’s career, but I think he was a true believer. He was headstrong, self-assured, and confident in his ideas, even against overwhelming opposition. And the mutual bad blood between his clique and the career investigators would have made it all but impossible for him to trust their findings, so it’s no surprise that he settled for what he saw as the next best answer.
In comments to the media following the publication of the report, Filotas laid out his vision of what he thought went wrong with the investigation. “You must remember that there was complete chaos and devastation at the site,” he told the Toronto Star. “It was like Dante’s Inferno. And here we have investigators, who are competent men, but they’ve never been at anything like this before. And frankly, I don’t think we had our first team on this. They’re wondering, ‘what are we going to do with the bodies? Should we leave them there? And what about the weapons?’ Then along comes Major General John Crosbie of the American Armed Forces. And we get the representatives of McDonnell Douglas. And senior engineers. All these people who are there to act as devils’ advocates, all there for their own particular reasons. And everyone’s sitting around in a motel room speculating about what could have caused the crash. Could it have been the engine? Nah, no way. How about ice on the wings then? Yeah, that’s clever. Ice on the wings” (DiManno, Toronto Star, 25 March 1989).
It has to be noted, first of all, that Filotas wasn’t even appointed to the Board until a year into the Arrow Air investigation, so he was not present for these opening phases. And second, his characterization of the events is insultingly dismissive of the sweeping effort that the CASB investigators put into solving the mystery. The evidence for ice on the wings was far more convincing than the hodgepodge of dubious gotchas that his group managed to put together. For his part, Tom Hinton, the Director of Investigations, responded to Filotas’s claims with incredulity: “This was one of the most comprehensive, thorough investigations ever conducted in Canada. It was exhaustive and it was done in accordance with strict Canadian standards,” he said. “We had 31 investigators working on the crash for three years, some of them exclusively. People with an international reputation. All the evidence that could be found was examined in great detail. And I know of no new evidence that has been brought forth since” (ibid).
In order to back up his claims, Filotas deployed a charm offensive in lieu of evidence. The dissenting Board members organized a media blitz, taking advantage of the fact that the professional investigators were forbidden from speaking publicly. At a press conference in front of many of North America’s leading journalists, the dissenters characterized the majority report as a cover-up that blamed pilot error for the crash by suggesting that “a tired crew disregarded ice on the wings” (Koring, The Globe and Mail, 3 December 1988), which was a purposefully disingenuous description of the findings. The majority Board members in turn accused the dissenters of “meddling and trying to conduct their own investigation without the required engineering and technical expertise” (ibid), but by then they had lost control of the narrative. Within days, opposition Liberal Party MPs were calling for a new inquiry.
Despite this, support for a new inquiry was lukewarm at best. Arrow Air stated that it saw no need for a new investigation given that all the relevant issues had been aired in the two reports. Transport Minister Benoit Bouchard was also opposed, telling the press that he had full confidence in the findings of the CASB staff. However, just days later he was publicly embarrassed when the Department of Transport released an internal report concluding that there was insufficient evidence to back up the majority’s findings. Calls for his resignation began to mount.
However, the biggest proponents of a new inquiry unfortunately were the victims’ families. Although the US NTSB has been responsible for victim outreach since the mid-1990s, it was certainly not expected that CASB Board members in the 1980s would attempt to sway grieving family members, but the dissenting members did exactly that. In 1988 Filotas penned a letter to Captain Griffin’s widow suggesting that the majority wanted to blame her husband, and other family members were contacted as well. The next of kin were not in a position to weigh the facts, and his arguments convinced many of them. Chairman Thorneycroft was forced to go against his best instincts in order to write competing letters, but the damage was done. Soon, family members were vocally supporting all kinds of “alternative” theories suggesting that the airplane was sabotaged by Egyptian or Libyan terrorists. American politicians got involved with their own outlandish theories too, like a US Congressman who dramatically presented a handwritten claim of responsibility supposedly received at the embassy in Mauritius from a group no one had ever heard of. Some journalists made the mistake of treating these “theories” seriously.
The humiliation that the career investigators suffered as a result of this circus was immeasurable. Speaking anonymously to the Globe and Mail, one CASB investigator said, “What you don’t expect is to be fried alive in the media, over a fire provided by an unidentified politico, while having both your arms tied behind you.” Another said of the dissenters, “If I went public with that kind of information, I’d end up in jail. …[The dissenters] want to go out and kick metal. The NTSB does that, but I can guarantee you the NTSB chairman himself wouldn’t go around asking ‘Did you check this? Did you check that?’ He wouldn’t dare; those guys know what the hell they’re doing” (French, The Globe and Mail, 7 May 1988).
Unfortunately, there was little they could do to restore the CASB’s honor. The president of the Canadian Air Line Pilots Association told the media that the CASB had lost all credibility, correctly (if tragically) suggesting that the agency should be disbanded because “even if their reports are accurate, no one is going to believe them anyway” (Windsor Star, 20 March 1989). The proposal to scrap the CASB was soon resurrected in parliament.
At the same time, the government ordered a judicial review of the Arrow Air investigation, which released its report in July 1989. The report concluded that neither camp had enough evidence to determine the cause of the crash to an adequate standard of proof. This finding was criticized, and rightly so, by both the majority and the dissent, who felt that the judge behind the review was setting an “unachievable precedent for the proof required to establish the cause of an accident” (Koring, the Globe and Mail, 26 July 1989). The judge appeared not to understand that the entire aviation industry runs on finding “possible” or “probable” causes of accidents, without necessarily being able to establish the level of certainty required for a conviction in criminal court. Filotas himself correctly pointed out that “there are crashes where there remains reasonable doubt but there is still a probable cause” (Ibid). Chairman Thorneycroft agreed, writing that the search for the most probable cause even in the absence of definitive proof is critical to aviation safety because it allows the identification of potential deficiencies even when evidence is scant. An official with the International Civil Aviation Organization further added, “The legal profession wants to have it in black and white… [but] aviation investigation is about the preponderance of evidence and good common sense” (Ibid).
As a direct result of the Arrow Air debacle, in June 1989 Canada’s parliament passed legislation disbanding the CASB, and in March 1990, the Transportation Safety Board of Canada was born. Like the NTSB, the TSB Board is limited to five members with clearly defined duties that don’t include accident investigation. The dissident members of the outgoing Board strongly protested the proposed organization of the TSB, lamenting that the new Board would have “no power.” Member Bobbitt told the media that he wanted a Board that would have the power to take an “active role” in investigations (Koring, The Globe and Mail, 14 January 1989). Personally, I find this position appalling. In no universe is it desirable to have a Board consisting of political appointees with no minimum qualifications who have the power to actively influence crash investigations. The outcome of the Arrow Air investigation is the clearest possible warning about the dangers of such an approach.
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Even after the CASB was dead and buried, the legacy of Arrow Air flight 1285 remained a story of strife and frustration. The dissenting Board members never stopped pushing their alternative theories, and Les Filotas even wrote a widely read book elaborating on his belief that the flight was brought down by a bomb and that the US and Canada conspired to cover it up. Filotas is the only living member of the dissent as of this writing, but he has continued to grant regular interviews well into his old age. Some readers might have seem him on “Mayday,” where his theories were given equal weight with those of the majority, despite the obvious inadequacies of the minority report. And to this day, in retrospective reports it’s still common to hear the dissidents’ ideas repeated as fact, or at least as credible possibilities, which they were not. Such is the lingering impact of the dissent’s underhanded media triumph.
In reality, what happened to the Arrow Air investigation was a travesty, a miscarriage of science, a victory for mystical thinking and misinformation. The crash that spawned this maelstrom of discord wasn’t especially unusual on its own merits — it was, at its heart, a classic takeoff accident, like countless others. What made it special was the conflict that it generated. The blame for that outcome lies only partially with the lack of hard evidence. The other part of the blame must lie with the men who instigated it, who in their pursuit of uncertain aims waded too deep into the waters of distrust, leaving behind a bitter wake that has failed to fade with the passage of time. And despite it all, on some riven hillside, 256 souls still lie in wait for a Christmas that never came.
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Special thanks to Leo Ortega, who assisted in finding archival press reports about the CASB.
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Don’t forget to listen to Controlled Pod Into Terrain, my podcast (with slides!), where I discuss aerospace disasters with my cohosts Ariadne and J! Check out our channel here, and listen to our latest episode, in which we join forces with an Airbus captain to discuss Air France flight 447. Alternatively, download audio-only versions via RSS.com, or look us up on Spotify!
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Note: this accident was previously featured in episode 65 of the plane crash series on December 1st, 2018, prior to the series’ arrival on Medium. This article is written without reference to and supersedes the original.
