Failures of Technique: The crash of Air New Zealand DC-8 ZK-NZB
On the 4th of July 1966, a then state-of-the-art Air New Zealand DC-8 cartwheeled and crashed on takeoff from Auckland during a training flight, killing two crewmembers and seriously injuring another three. Shocked New Zealanders feared that a disaster involving passengers had been narrowly avoided, but as it turned out, the cause of the crash was unique to the nature of training flights in particular — a fascinating fault that reared its head during a high-stakes takeoff. Investigators discovered that when the training captain attempted to simulate the failure of engine 4 just moments before liftoff, the engine actually went into reverse, dragging the plane back to earth before it had a chance to gain speed and altitude. At question were both the instructor’s technique and the design of the DC-8’s power levers, which interacted in just the right way to give the trainee pilot a much more serious emergency than he bargained for. The findings revealed a previously unknown design flaw and represented an early investigative foray into the field of cockpit ergonomics — but the story of Air New Zealand’s forgotten first disaster also provides an interesting opportunity to discuss some of the ways that aircraft design and operation have dramatically changed in the nearly six decades since.
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Prior to the advent of the jet age, it wasn’t particularly easy for most of the world to fly to New Zealand. Any traveler willing to undertake the journey would have braved multiple days aboard slow, noisy piston liners before boarding a pre-war era flying boat for the final trip across the Tasman Sea. In fact, the airline now called Air New Zealand, then known as Tasman Empire Airways Limited, didn’t acquire its first airplane with wheels until 1954, long after the age of the flying boat had come to an end nearly everywhere else. Flying boat services from New Zealand to Tahiti continued as late as 1960, by which time airlines in nearby Australia had already taken delivery of their first passenger jets.
The isolation of New Zealand finally began to crumble in 1965, when TEAL placed an order for three Douglas DC-8 jets, with which it planned to inaugurate the country’s first regular services to the United States and East Asia. Concurrent with its modernization, TEAL officially changed its name to Air New Zealand, as the airline is still known today.
The first DC-8 arrived in New Zealand with much fanfare on the 20th of July 1965, followed three weeks later by the second, which was registered as ZK-NZB — the aircraft later involved in the accident. A third DC-8 arrived later in August, and when Auckland’s new international airport opened in January 1966, regular services began in earnest.
Part of Air New Zealand’s modernization process involved training its pilots to make the massive technological leap to the brand new DC-8s. Among the first cohort to undergo training was 46-year-old Captain Donal McLachlan, a veteran pilot who had been flying for TEAL and Air New Zealand since 1947, back in the flying boat era. By the time the first DC-8s arrived in the middle of 1965, he had already finished his type training, and in September of that year he also qualified as an instructor, enabling him to train the next wave of DC-8 flight crews.
On the 4th of July 1966, Captain McLachlan oversaw a regular training session involving ZK-NZB, which had been withdrawn from passenger service that day to facilitate the qualification of several first officers, including 29-year-old Brian Ruffell, among others. Ruffell had recently completed the regular DC-8 training course and was now receiving “continuation training,” the meaning of which is not explained in the report, although it could refer to recurrent training, if he finished his type rating shortly before recurrent training was scheduled. At that time he had just 21 hours in the DC-8, out of 4,200 total.
The regular crew that day also included 33-year-old Flight Engineer Gordon Tonkin, whose job was to operate aircraft systems. Two other pilots were also on board, consisting of Captain Bernard Wyatt and First Officer Kenneth Sawyer, who were seated in the observer’s seat and navigator’s station, respectively. The official report states that they had “no official duties,” but on these types of training flights it’s not uncommon to carry a supernumerary crew in order to assist the instructor and trainee in the event of unexpected circumstances.
ZK-NZB had already been flying in and out of Auckland Airport on training flights for most of the day when the crew picked it up on the apron that afternoon and requested permission to start the engines. The weather that day wasn’t perfect, with cumulus overcast at 1,500 feet with scattered showers, but the wind was almost calm, presenting little difficulty for the new first officer.
At 15:59, ZK-NZB lined up on Auckland’s runway 23 and prepared for takeoff, with trainee First Officer Ruffell at the controls. Being familiar with the concept of such training flights, he expected Captain McLachlan to test him by simulating an engine failure after decision speed, and that was in fact McLachlan’s intention.
Decision speed, or V1, is the highest speed at which it is safe to reject a takeoff. Pilots calculate it before each flight, taking into account the weight of the aircraft, the length of the runway, the presence of water or snow, and various other factors. After reaching V1, the pilot must continue the takeoff, regardless of any failures that may occur — which is why an engine failure after V1 is considered one of the most difficult emergencies that a pilot can face. Bringing the aircraft safely into the air with less than normal thrust and an asymmetric yawing force requires considerable skill and practice.
Today, training for this type of emergency on airliner type aircraft is performed in a simulator. Although simulated engine failure on takeoff exercises are performed in small twins as part of a pilot’s initial multi-engine rating, this training today is considered too risky to attempt in a large passenger jet, nor is it cost effective. Modern simulators make it possible to avoid both the risk and expense. Nevertheless, this type of training was historically more common due to the limited number of simulators and those simulators’ lack of fidelity. In fact, New Zealand investigators would later write that an engine failure on takeoff in the actual aircraft was an essential part of any pilot’s qualification, and that for this maneuver a simulator simply would not do — which, as it turns out, was only true by 1960s standards.
During instructional flights in the real aircraft, the instructor normally simulates an engine failure by moving one power lever to idle without warning. The engine is not shut down and thrust can be restored immediately if needed. The trainee, meanwhile, should detect the engine failure via the sensation of yaw from the asymmetric thrust, which should then be countered using the rudder to keep the plane flying straight. After liftoff, the pilot must ensure that the airspeed remains above V2, the engine failure safety speed, which is designed to ensure that the airplane has enough lift to climb safely with a failed engine. Only once the airplane is stabilized in a climb and has reached a safe altitude will the trainee practice the checklist — everything before that must come from memory.
All of these tasks were foremost in First Officer Ruffell’s mind when he began the takeoff roll. Acceleration was normal, but he strongly suspected that just before liftoff, Captain McLachlan would move one power lever to idle, and he had no way of knowing which one.
At a speed of 103 knots, the aircraft reached V1, and Ruffell was committed to takeoff. Within the next few seconds they would reach their calculated rotation speed, or VR, which was 118 knots. At that point Ruffell would pull the nose up to bring the plane off the runway. McLachlan’s job was to simulate an engine failure after V1 but before reaching VR, which is the most adverse point for such a malfunction, and thus the greatest test of the trainee’s flying skills.
At the moment of V1, the supernumerary Captain Wyatt was standing up, observing the process of the takeoff, when he saw Captain McLachlan snap the №4 power lever to idle. He noticed that instead of grasping the knob at the top of the lever, McLachlan grabbed an approximately 5-centimeter rod protruding from the right side of the rightmost, №4 power lever, with which he dragged the lever back to idle, using the rod as a handle.
The proper name for this rod was the “spoiler disarm extension,” and it was by no means intended as a handle. The actual purpose of the rod, as far as I have been able to tell, was to push the adjacent spoiler lever out of the “extend” detent when the power levers were advanced to high power.
Jet aircraft such as the DC-8 are normally equipped with spoilers, which are essentially flat panels that rise up from the upper wing surface to “spoil” the airflow and reduce lift. On most aircraft, spoilers can perform three different functions: first, to remove lift on landing in order to ensure the airplane settles onto its wheels; second, to remove lift in flight, in order to descend without increasing speed (“speed brakes”); and third, to assist in roll control, by removing lift on the “down” wing during a turn.
As readers familiar with my previous article on Air Canada flight 621 might already remember, the DC-8’s spoilers fulfilled only two of these functions. The DC-8 was equipped with ground spoilers for use after touchdown and roll spoilers for roll assistance, but it had no “speed brake” function. As such, the spoiler lever on the center console was only intended for use after touchdown. Pilots normally armed the spoilers prior to touchdown by pulling the lever outward, at which point the spoilers would deploy automatically when there was weight on the wheels. Alternatively, the spoilers could be deployed manually after touchdown by pulling the lever back to the “extend” detent.
If the spoiler lever was left in the “extend” detent after landing, this should be detected before the next takeoff as part of the pre-flight checks. However, if this check was for some reason missed, then an attempt to take off with the spoilers deployed would likely end in catastrophe as the plane would be unable to lift off the ground. As far as I have been able to tell with the scant documentation available, the spoiler disarm extension was intended as an assurance against this scenario. If the spoiler lever was in the extended position when the power levers were advanced, the extension would catch on the spoiler lever and push it back to the “retract” detent. The name of the extension implies that it can also disarm the spoilers in the event of a go-around after the pilots have armed the spoilers for landing, but it’s unclear to me how this would work.
In any case, there was no rule specifically forbidding Captain McLachlan from moving the №4 power lever using the spoiler disarm extension, nor would it have occurred to him that this could be in any way hazardous. But within seconds of his unorthodox action, it became clear that something was terribly wrong with the airplane.
As First Officer Ruffell continued to fly the plane toward VR, he felt the asymmetric thrust from the idled engine and applied left rudder to keep the plane flying straight. He also applied forward pressure on his control column to keep the nose wheel on the ground, improving directional control. Seconds later they reached VR and he began to pull back, although McLachlan never made the standard “rotate” callout — possibly deliberately, to test whether Ruffell was watching his airspeed.
As soon as Ruffell began to pull back, the plane lurched into the air, and it was immediately obvious that something was amiss. The drag that Ruffell could feel from the right side of the plane was so great that he thought McLachlan must have rolled back both engines on that side. He applied full left rudder to cancel the yaw, but the airplane was slowing down, its speed peaking at 124.5 knots before it began to decrease. And to make matters worse, the right wing was dipping, dragging the plane downward — and Ruffell had neither any idea why, nor any time to fix it.
The DC-8’s altitude reached approximately 100 feet above the ground before it began to descend, slewing right of course while in a steepening right bank. Neither pilot exchanged any words as they struggled to determine what was going on. There were no alarms, no stall warnings, no obvious sign of any mechanical failure.
Fearing that they were about to crash, the supernumerary Captain Wyatt attempted to scramble to safety but he had no time to sit down and fasten his seatbelt. Instead, he threw himself to the floor behind the captain’s seat and held on for dear life.
Just seconds after liftoff, now banked around 40 degrees to the right, the DC-8’s right wingtip struck the ground in the grass verge beside the runway, digging a long furrow through the mud. The plane veered further right, its wing disintegrating in its wake; in the nearby terminal travelers began to flee in alarm, fearing that the aircraft was careening in their direction. But before it could do so, the ground contact dragged the plane to earth, pivoting it around its right wingtip, until the nose smashed headlong into the grass with enormous force. The cockpit and forward cabin snapped off like a pencil tip and slid upside down across the ground, while the wings and fuselage spun around and slid right-side-up across a taxiway. Engines 1, 3, and 4 separated from the wings and bounced along in its wake, but engine 2 became lodged under the left wing and burst into flames, triggering a fire that immediately ignited leaking fuel. Smoke surged into the sky over Auckland Airport as the crash alarm sounded and fire trucks peeled out of the station.
Dozens of people around the airport witnessed the crash, but few realized that the DC-8 was involved in a training exercise. Numerous relatives of passengers on a flight to Brisbane that had departed 10 minutes earlier missed the start of the takeoff roll and thought that the passenger flight had come around for an emergency landing, only to crash. Firefighters were also unaware that there were no passengers on board, discovering this only when they arrived at the burning cabin to find no one inside.
When firefighters reached the mangled and overturned cockpit, they found the five pilots still trapped within, all gravely injured. A lengthy and difficult rescue operation ensued as first responders cut their way into the cockpit to extract the trapped crew. Unfortunately, by the time they succeeded, Captain McLachlan and Flight Engineer Tonkin were dead. First Officer Ruffell and the two observers, Captain Wyatt and First Officer Sawyer, survived with very serious injuries.
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The crash was the first fatal accident in the history of Air New Zealand or its predecessor TEAL, as well as the first, and to date only, fatal crash of a commercial jet on New Zealand soil. The fact that no passengers were involved came as a relief to some, but many others worried that whatever went wrong could strike again, with even more severe consequences. It was up to the New Zealand Accidents Investigation Branch (AIB) to find out why the DC-8 cartwheeled on takeoff, and whether passenger flights might be in danger.
The very first clue came from several pilots and aviation professionals who witnessed the crash from a building adjacent to the runway. Four of these witnesses heard a change in engine noise shortly before rotation, followed by a startling sight: the fan cascade doors on the №4 engine were open.
The fan cascade doors are part of the DC-8’s thrust reversing system. Like most jets, the DC-8 can reverse the direction of engine thrust in order to help the plane slow down on landing, but the type is unique in that the inboard thrust reversers, on engines 2 and 3, can also be deployed in flight in order to reduce airspeed in the manner of a speed brake. (Among Western commercial aircraft, only the DC-8 and the Concorde have this capability.) This was, however, irrelevant to the phase of flight that ZK-NZB was in at the time of the crash, not to mention that the №4 reverser should only deploy on the ground regardless.
Air New Zealand’s DC-8–52s were powered by Pratt & Whitney JT3D turbofan engines, unlike early DC-8 models that had turbojet engines. Whereas a turbojet engine generates thrust from exhaust alone, a turbofan generates thrust using both exhaust and so-called “bypass air” accelerated around the exterior of the engine core by the fan at the front of the engine. For this reason, the thrust reversers on the JT3D engine reversed the direction of thrust in two separate locations, one for the exhaust and one for the bypass air. When the pilot selected reverse thrust, the fan cascade doors would open to divert bypass air forward, while the primary cascade sleeve, which surrounded the aft portion of the engine, translated rearward to expose the primary cascades. Two bucket doors then closed over the exhaust outlet, forcing exhaust air forward through the primary cascades.
Investigators could not ignore the fact that several independent witnesses, many of whom had professional knowledge of the DC-8, all saw the fan cascade doors open on engine 4. In order to be extra sure, investigators also taxied a DC-8 to the same point where the witnesses saw it and deployed the №4 thrust reverser, which confirmed that the status of the fan cascade doors was easily visible from the witnesses’ location. But when the AIB examined the remains of the №4 engine, they discovered that while the engine was not generating power at impact, the reverser was in the stowed position. So was it possible that the reverser was initially deployed, but then stowed again before the engine struck the ground? Or were the witnesses mistaken?
Finding out was not as simple as it would be today. ZK-NZB was equipped with an early flight data recorder, but it only captured basic parameters such as airspeed, heading, and altitude; the status of the thrust reversers was not recorded. However, from the available data, investigators could tell that the aircraft started losing speed shortly after liftoff, reducing from a peak of 124.5 knots to 118 knots at impact. This behavior was unexpected and abnormal, but it should not have been catastrophic.
Investigators knew that the instructor likely intended to perform an engine failure on takeoff drill, and that the engine he selected was likely №4, judging by the fact that this engine was not producing thrust at impact. However, assuming that the №4 engine was merely rolled back, a loss of control should not have occurred.
Every multi-engine airplane has a minimum speed at which directional control can be maintained with one failed engine. Because control surface authority decreases with decreasing airspeed, there is a point below which the flight controls will not be able to counteract the effect of asymmetric thrust from a failed engine. This speed is called minimum control speed (airborne), or Vmca, and if an aircraft with a failed engine decelerates below Vmca the pilot will lose control. A more detailed explanation of the criteria used to determine Vmca is shown above.
Because of this fact, the value of VR, rotation speed, must be at least five knots above Vmca. This ensures that by the time the plane becomes airborne, it’s already traveling faster than Vmca, and directional control can be maintained in the event of an engine failure.
Investigators double checked the flight crew’s calculations and found that the value of Vmca on the accident flight was 113 knots, and VR was 118 knots — identical to the values calculated by the crew before the fatal flight. Furthermore, the aircraft never decelerated below Vmca at any point prior to ground impact. And yet, by the time the plane struck the ground, it had veered six degrees right of course and was in a 40-degree right bank, indicating that the pilots were unable to maintain control.
After recovering in hospital, First Officer Ruffell revealed that the drag on the right side of the airplane was greater than he would expect from a failed engine, and he was unable to maintain directional control even after applying full left rudder. Two other witnesses independently confirmed that they saw the rudder deflect fully left. This valuable insight, combined with the flight data analysis, strongly indicated to investigators that whatever happened on takeoff was no mere engine failure. In that case, the witnesses’ observation that the №4 thrust reverser was deployed had to be taken seriously.
In order to find out whether a deployed thrust reverser could have caused the crash, investigators turned to Douglas Aircraft, who conducted an engineering simulation. Douglas’s calculations revealed that with the №4 thrust reverser deployed and engine thrust at idle, Vmca was not 113 knots, but 141 knots — a far greater speed than ZK-NZB ever achieved. Furthermore, the drag from the reversed thrust would not only cause the airplane to experience deviations in yaw, but the plume of disturbed air in front of the wing would also create an asymmetric reduction in lift, causing the plane to bank sharply. Additionally, Douglas determined that for every degree of bank toward the reversed engine, Vmca would increase by a further 3 knots, causing the aircraft to effectively dig its own grave. But even these calculations were conservative, since they assumed the engine was at reverse idle, when in fact it would have initially generated considerably greater reverse thrust than this, since the DC-8’s engines required 14 seconds to spool down to idle from takeoff thrust. Considering all of these factors, there would have been no way for the pilots to stop the aircraft from banking until the wingtip struck the ground, unless the thrust reverser was stowed almost immediately after it was deployed.
Since the reverser was found in the stowed position after the crash, Captain McLachlan must indeed have stowed it sometime before impact, but not quickly enough to avoid the accident. First Officer Ruffell never glanced at the power levers or the reverser status indicators and did not know when McLachlan stowed the reverser, or indeed that the reverser had deployed at all. A thrust reverser light would have come on to indicate the deployed status, but none of the survivors could recall seeing it amid the chaos. As for McLachlan, investigators surmised that he might not have noticed the status of the reverser until it was too late, since he would have been focusing on Ruffell’s response to the simulated failure.
Between the witness statements and the engineering simulation, investigators believed that the deployment of the №4 thrust reverser was the most likely reason for the accident. But such a suspicion would be meaningless unless they could show how the reverser became deployed in the first place.
A close examination of the reverser mechanism revealed no obvious malfunction that could have caused it to deploy during the accident flight. Rather, the simplest way to cause a reverser to deploy during the takeoff roll would have been to actuate the reverser lever in the cockpit.
The thrust reverser levers, technically called thrust brake levers on the DC-8, were hinged to the upper forward portion of each power lever and could be pulled upward and back to deploy the reversers. Motion of the thrust brake lever into the reverse detent was only possible if the power lever was at idle, and the reversers for engines 1 and 4 could only be activated if the landing gear was down. Technically there was nothing preventing a pilot from activating the №1 and №4 reversers in flight as long as the gear was down, even though only №2 and №3 were intended for such use, but these outboard engines were at least limited to reverse idle when there was no weight on the wheels. On the ground, reverse thrust greater than idle could be used on all four engines.
Investigators wondered whether Captain McLachlan could have accidentally caused the №4 reverser to deploy as he was moving the №4 power lever to idle. A clue as to how emerged during interviews with other Air New Zealand DC-8 pilots.
When the AIB inquired about similar incidents, two Air New Zealand first officers mentioned that during a previous training flight in ZK-NZB with the very same Captain McLachlan, the latter attempted to simulate an engine failure while on the ground during a touch-and-go landing. Instead of clutching the entire №4 power lever knob in his hand, McLachlan grasped the knob with only his thumb and forefinger, then snapped the lever back very rapidly. Somehow, as he did so, the thrust brake lever entered the reverse thrust position, but no one saw how it happened. The №4 reverser light immediately came on and the thrust reverser deployed. The first officer, who was flying the airplane, was unable to maintain directional control even with full left rudder, and the aircraft continued to yaw to the right until Captain McLachlan returned the thrust brake lever to the stowed position, after which a normal three-engine climb was accomplished.
During that incident, the first officer was able to push the nose down to prevent a loss of airspeed and the right bank never exceeded ten degrees. The AIB believed that control was regained due to the higher speed of the aircraft to begin with — around 140 knots — and due to Captain McLachlan’s swifter reaction. However, the incident was neither reported nor investigated, despite its evident seriousness.
On the accident flight, McLachlan used a different technique. According to the surviving Captain Wyatt, he snapped the power lever back by using the spoiler disarm extension as a handle, rather than grasping the knob with his thumb and forefinger. Investigators speculated that he had altered his technique in an attempt to avoid repeating the earlier reverser deployment. But what was it about his technique that had caused it?
Using a parked aircraft, investigators attempted to replicate techniques employed by Captain McLachlan during both of the incident flights. Snapping the power lever back rapidly with the knob grasped between the thumb and forefinger, they were astonished to observe that sometimes — but not always — the motion imparted sufficient momentum to the thrust brake lever that it continued upward into the reverse detent due to inertia as soon as the power lever slammed into the flight idle stop.
If the pilot grasped the knob in the normal fashion, enclosing it in their fist, then the above scenario couldn’t occur because the pilot’s fingers would prevent the thrust brake lever from rising far enough to trigger the reverser. However, McLachlan might have thought that he had somehow caught the thrust brake lever with his hand, causing it to deploy — in which case he might have thought he could mitigate the risk by grasping the spoiler disarm extension, which was farther from the thrust brake lever. Unfortunately, investigators found that triggering the №4 reverser while holding the spoiler disarm extension was actually even easier.
Having discovered that it was possible to inadvertently deploy a reverser simply by moving a power lever too quickly, AIB investigators recognized that immediate action was necessary to prevent a recurrence. Within hours of the experiments, notification was sent to Douglas Aircraft, who immediately reported back that they could reproduce the error. All DC-8 operators were swiftly notified of the issue and pilots were told to be aware of the risk.
This finding necessarily raised the question of whether McLachlan’s technique should be considered inappropriate. Although he couldn’t have known the true danger of snapping the power lever back, it was also true that there was no compelling reason to do so. Investigators noted that a jet engine always takes the same amount of time to spool down, approximately 14 seconds in the case of the JT3D, regardless of how quickly the power lever is moved. However, on earlier piston engine airplanes, the speed with which one closed the throttles did influence the speed of the engine shutdown, and instructors had long considered a quick shutdown more realistic. Although McLachlan flew much of his career on piston aircraft, he should in principle have known that the old logic did not apply to a jet. The AIB therefore dismissed the possibility that he could have been mistaken about the effectiveness of his technique, although the possibility can’t be entirely ruled out. Instead, the AIB preferred the hypothesis that he took action rapidly due to the difficulty of timing the engine failure within the 3 second interval between V1 and VR. Additionally, he might have moved the power lever quickly to minimize the chance that the trainee would see which lever he had selected.
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Having established these facts, the AIB believed they understood the most likely causes of the accident. During the simulated engine failure, Captain McLachlan snapped the power lever back to idle too quickly, causing the thrust brake lever to rise into the reverse detent. The thrust reverser deployed, initially at power above idle, because the engine was still spooling down. This caused a large yaw moment and a loss of lift that were uncontrollable at the speed the aircraft was traveling. Amid the chaos, McLachlan didn’t realize his mistake until it was already too late to prevent ground contact.
In the interest of calming the public, the AIB issued a special statement to the media, informing New Zealanders that the circumstances of the accident could only arise during a training exercise, and not during a regular flight. Even if a pilot snapped a thrust lever back in response to a real engine failure, no reverse thrust could possibly be produced by an engine that wasn’t working.
In their final report, investigators recommended that Douglas create a standardized power lever rollback technique, but they were very clear that this alone would not be enough to completely prevent a recurrence. “It is a well recognized fact that if a particular thing can be done, albeit quite unintentionally, then sooner or later some person will do it,” the AIB wrote. The only permanent solution in their view was a mechanical intervention that would eliminate any possibility of inadvertent thrust reverser activation. The report doesn’t say whether Douglas implemented such a fix, but it would not surprise me if they did.
Another major issue highlighted by the AIB was the failure to share information about the previous incident involving Captain McLachlan, both within the company and outside of it. No mechanism existed for the flight crew to report the inadvertent reverser activation and it was neither investigated by Air New Zealand nor notified to Douglas — a lapse that ultimately cost the lives of McLachlan and Tonkin when this plainly dangerous issue resurfaced.
Incident reporting is foundational to modern aviation safety. An incident reported now can save lives in the future, even if seemingly minor — and to be clear, this one was not minor. But the historical culture in most industries was one of concealment, hiding incidents for fear of backlash or to preserve so-called trade secrets, and in 1966 the airline industry had yet to fully recognize the value of dismantling this insular tradition. In contrast, major airlines today have extensive systems for gathering incident data, analyzing it, and informing the necessary authorities while preserving the privacy of those involved. Under such a system this crash would almost certainly have been prevented.
Regarding the question of which in-service experiences ought to be shared, the AIB wrote, “To this there can be only one answer, for it is based on a great many lessons learned from the past: share every experience, report every incident immediately, however trivial it may be considered to be.”
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In the end, although the AIB possessed the authority to find an individual or organization legally responsible for the crash, they chose not to do so, citing the fact that no person or group was obviously to blame. Most investigative agencies today lack this authority, and for good reason, so in my opinion it was wise for the AIB not to use it.
It could be argued that Douglas Aircraft was primarily responsible due to the design of the thrust brake levers, which enabled a potentially catastrophic user error. If such a design flaw had escaped notice in 2024, forgiveness would not come so easily. But in 1958, when the DC-8 entered service, manufacturers’ understanding of cockpit ergonomics was a mere shadow of what it is today, and even more egregious errors were far from uncommon. In my previous article on Air Canada flight 621, I discussed how the DC-8 flight manual mentioned a system that would prevent the spoilers from being deployed in the air, even though no such system actually existed — a truly inexplicable error. Douglas Aircraft was certainly not the most careful of the major manufacturers, but it was also hardly alone in its failure to identify the potential for catastrophic accidents as a result of seemingly minor misuse of the controls.
And yet, while massive strides have been made, designs intolerant of human error still persist. For instance, in my article on the 2011 crash of Airlines PNG flight 1600, I related the story of a turboprop pilot who slammed both throttle levers to idle with sufficient force to raise the flight idle gates and move the levers into the reverse position, causing a crash that killed 28 people. Was that accident so different from this one? In some key respects it was not.
On the one hand, completely preventing pilot misuse of the controls is almost impossible, but on the other hand, mitigating the consequences is not. A modern aircraft could have been designed to detect the deployment of a reverser after the wheels left the ground, and the reverser could have been stowed automatically. Such a system, which was not envisioned in the AIB report, could have prevented this accident, since the deployed №4 reverser was not intended for in-flight use. Modern regulations require that once a jet aircraft is airborne, it should not be possible for a reverser to be in a deployed condition, regardless of the position of the corresponding cockpit control, unless in-flight deployment is intended as part of the design.
In its final recommendation, the AIB urged the International Civil Aviation Organization to study the causes of training accidents around the world, and find ways to prevent them. Ultimately, efforts to reduce training accidents have succeeded, but the determining factor was the availability of advanced simulators. As I discussed earlier in this article, in airline operations, engine failures after V1 are no longer practiced in the real aircraft. But there has also been a change in attitude among instructors and trainees alike. In 1966, a training exercise like the one in this story would have been aimed primarily at “testing” the cadet — to find out whether they were made of the “right stuff,” so to speak. Instructors did not necessarily feel that their role was to help the trainee achieve the expected standards, but rather to challenge the trainee to rise to those standards themselves. This sounds good enough on paper, but in reality it results in worse training outcomes and exposes flight crews to unnecessary risk. The modern viewpoint is that cadets should not fear training, but should treat it is a positive experience that imparts positive knowledge and skills, while the instructor’s job is to cultivate that experience. An exercise such as an engine failure after V1, if it were attempted today, would not be a complete surprise, but would be briefed beforehand in order to reduce risk and ensure the appropriate training outcome.
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If this nearly 60-year-old training accident still has any significance, it lies in the comparison between 1960s practices and modern standards. Much has been done to incrementally reduce risk in all sectors of aviation, including not only passenger flights but also other types of routine operations where fewer lives are at stake. The industry no longer considers it acceptable to expose pilots to such elevated risks in the name of preparedness when safer options exist. But these modern practices were built on lessons learned from tragedies like this one, which faded quickly from the headlines, if they ever appeared there at all, to be preserved only in the memories of those who were there, and in official reports lingering in public archives. Learning about these accidents can help ensure that those practices are not taken for granted. Failing that, at the very least we can read the story of this preventable accident and look back with relief at how far aviation has come.
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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 on the fiery demise of Swissair flight 111. Alternatively, download audio-only versions via RSS.com, or look us up on Spotify!
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