Tempting Fate: The crash of Dana Air flight 992

The tail section of Dana Air flight 992 burns after the crash. (allafrica.com)

On the 3rd of June 2012, a Nigerian airliner on approach to Lagos inexplicably lost power on both engines. The pilots issued a frantic mayday call before the McDonnell Douglas MD-83 slammed into a densely populated suburb, killing all 153 people on board and at least six more on the ground. The plane was completely obliterated and three large buildings were reduced to rubble. But when investigators arrived to pick over the mangled debris, they didn’t look at the crash in isolation — in fact, this was the fifth major air disaster in Nigeria in the past decade, an astonishing rate for a country with a relatively small aviation industry.

The facts revealed by the subsequent inquiry painted a disturbing picture. Negligent maintenance by a US-based contractor most likely caused damage that prevented fuel from reaching the engines, resulting a total loss of power. But the engines didn’t fail at the same time — one failed 17 minutes into the flight, and the other gave out on approach; yet for some reason the crew did almost nothing to respond to the emergency. How could such a dangerous maintenance error go undetected? And how could a crew ignore such a dire emergency? The answers to these questions would prompt a reckoning for the entire Nigerian aviation system, leading to notable improvements in what used to be one of the most dangerous places to fly.

5N-RAM, the aircraft involved in the accident. (Kenneth Iwelumo)

Dana Air is a small airline specializing in domestic scheduled and charter flights within Nigeria. Dana Air was one of many small airlines that sprang up in Nigeria in the 1990s and 2000s to cater to a growing demand for air travel in a country where the road and rail networks are extremely poor. With a small fleet of half a dozen second-hand McDonnell Douglas and Boeing jets, the airline first began passenger services between five major cities in Nigeria in 2008.

One of the planes in Dana Air’s fleet was a McDonnell Douglas MD-83 with the registration 5N-RAM, which was built in 1990 and had spent the first 17 years of its life flying for Alaska Airlines. The twin rear-engine jet found a second life at Dana Air, one of countless planes sold to African companies after being retired from service in the United States. Like most of its competitors, Dana Air ran something of an ad-hoc operation: tickets on Dana Air flights were often bought with cash at the airport terminal minutes before the scheduled time of departure.

5N-RAM’s first three years flying for Dana Air were uneventful, until the second half of 2011, when both of the plane’s engines were sent to Miami, Florida for a scheduled overhaul. Each of the two Pratt & Whitney JT8D turbofan engines was serviced by the Miami-based contractor Millennium Engine Associates Inc., which performed all of Dana Air’s heavy engine maintenance.

The JT8D engine is one of the most popular jet engines ever made, but like any other model, it had its share of issues. One such issue related to the system that delivers fuel to the engines. Fuel is injected into the combustion chamber via spray nozzles, which are attached to two fuel manifolds — pipe segments where one stream is split into several. Each of the two manifolds, designated primary and secondary respectively, is fed by a single inlet tube. In the 1990s and early 2000s, the inlet tube on the secondary manifold was found to be too weak for the job it was supposed to do; over time, it tended to crack and then eventually shear off completely due to thermal stress causing repeated expansion and contraction of the metal. This recurring problem resulted in 94 engines having to be removed from service for unscheduled maintenance, two emergency landings, one in-flight engine shutdown, and a fire. In 2003, Pratt & Whitney issued a service bulletin asking all operators of JT8D engines to replace the secondary fuel manifold assembly with a new version that was twice as strong, which would greatly extend its fatigue life.

A basic diagram of an MD-80 engine showing the location of the primary and secondary fuel manifolds. (AIB)

In 2005, while still in service with Alaska Airlines, 5N-RAM’s right engine was overhauled by Volvo in Sweden, which brought it into compliance with the Pratt & Whitney service bulletin. However, the left engine was not overhauled and was sold with the plane to Dana Air in its original condition, weak fuel pipes and all. Proper maintenance would have ensured that this wasn’t a major issue, but Millennium Engine Associates was not exactly a top tier contractor. When they overhauled the engines in 2011, they didn’t update the left engine to comply with the service bulletin, even though they were encouraged to do so. Even worse, they apparently had a habit of installing JT8D fuel manifolds incorrectly. If any of the parts of the manifold assembly are out of alignment, it can put extra twisting or bending stress on the secondary manifold inlet tubes, causing them to eventually shear off completely. The details of what exactly Millennium did to these manifolds are not known.

An example of a sheared inlet tube caused by an improperly installed fairing on another aircraft. (AIB)

Several months later, on the third of June 2012, 5N-RAM prepared to operate Dana Air flight 992 from Nigeria’s capital, Abuja, to the port city of Lagos, the most populous urban area in Africa. In command were two expatriate pilots — the captain was Peter Waxtan, an American; and the first officer was Mahendra Singh Rathore, an Indian national. Although Rathore was largely unremarkable, the fact that the captain was American was a red flag from the beginning. Most Americans flying for shoestring African airlines like Dana Air are there not by choice, but because they couldn’t make the cut at more established carriers. In fact, Waxtan had flown for 12 years with Spirit, followed by a brief stint at the Miami-based charter company Falcon Airlines. But in 2009 he had his license revoked by the Federal Aviation Administration for making repeated hard landings and fixing panels without reporting them in the technical log. Having been cast out from the American aviation community, he now found himself running domestic passenger flights in Nigeria, where he worked on rotation — 30 days on, 15 days off. Flight 992 was to be his last flight for the month, and afterward he was expecting to fly back to America to see his fiancée.

An undated photo of Captain Peter Waxtan, probably while he was still flying for Spirit. (In Memory of Peter Waxtan, Facebook)

On the ground in Abuja, the captain twice delayed passenger boarding due to an ongoing meeting between all the crewmembers. The contents of this discussion are unknown, although the captain did tell ground staff, without explanation, that the rear passenger door should not be opened. After the crew finished their meeting, 147 passengers boarded the plane, which in addition to the six crew made for a total of 153 people on board.

Dana Air flight 992 took off at 2:58 p.m. and climbed toward its cruise altitude, heading southwest toward Lagos. Within minutes, however, the left engine apparently stopped responding to throttle commands. It is thought that the weakened secondary fuel manifold inlet tube fractured, resulting in a significant fuel flow reduction that prevented the engine from generating greater than idle power. When the cockpit voice recording began at 3:15, the pilots were already discussing the problem. As far as they could tell, the engine was still running, but moving the throttle lever did absolutely nothing to change its thrust output. Remarkably, the pilots appeared to conclude that this was not a serious problem, and that they could continue the flight normally! Neither Waxtan nor Rathore told air traffic control about the problem, nor did they even call the airline’s operations center for advice. In fact, Waxtan at one point said, “We just want to get [the aircraft] home,” by which he must have meant that he preferred to have the plane checked out at Dana Air’s maintenance headquarters at Lagos’ Murtala Muhammed International Airport.

Route of Dana Air flight 992. (Google)

First Officer Rathore then suggested that they call in a Dana Air engineer, who was riding on board the plane in order to reposition to Lagos, to see if he had any advice. But Captain Waxtan refused, telling Rathore, “I don’t need him here cause we can figure it out, he’s not going to be able to help us.” Apparently the captain and this particular engineer were having some sort of feud, as Waxtan stated, “This is the guy that had an issue with us. Uh, he’s pissed off at us.” The dispute apparently had something to do with a panel by the rear passenger exit door, which could have been related to the request not to open it.

With its left engine at idle, or even totally inoperative, flight 992 continued onward normally toward Lagos. The pilots never consulted the appropriate non-normal checklist and never discussed diverting. At 3:31, already nearing Lagos, the pilots received clearance to approach runway 18R at Murtala Muhammed International Airport. Once again, they tried to increase thrust on the left engine and found it to be unresponsive. Still, no one even so much as suggested that they transmit any sort of distress call. Captain Waxtan confirmed that the right engine was working properly, and proceeded with the flight. But as the approach continued and the left engine still refused to respond, he became increasingly concerned by the fact that they would have to call in the failure and that the plane would be taken out of service. “We’re gonna be investigated by the NCAA!” he lamented, expressing alarm at the possibility that Nigeria’s civil aviation authority might look into the incident.

By 3:40, flight 992 was on approach to runway 18R some 28km short of the threshold. The pilots had forged a roundabout path through the approach and landing checklists, eventually checking off most of the required items. They did not even consider consulting the special single-engine landing checklist, which would have outlined some additional safety measures that they ought to have taken.

After descending at idle or near-idle thrust for a time, Captain Waxtan attempted to increase engine power to slow their rate of descent for landing. But when he advanced the throttle lever on the supposedly functional right engine, there was no response!

“Did both engines come up?” First Officer Rathore asked.

“Negative!” Waxtan exclaimed. Both engines remained at idle, generating no forward thrust, and refused to accelerate. They technically hadn’t failed, but the effect was the same. Now faced with a dire emergency, it was incumbent upon the crew to break out the dual engine failure checklist and figure out what they would need to do to get the plane on the ground safely, but they did not.

At 3:42, First Officer Rathore finally declared an emergency. “DANACO 992,” he said, “Dual engine failure, negative response from the throttles!” But instead of staying on the line to guide them down, the approach controller simply gave flight 992 the frequency to contact the tower and handed them over. They never did manage to call the tower; the distress call was the flight’s last communication with air traffic control.

With the runway in sight, Captain Waxtan struggled to keep his powerless aircraft aloft. “We just lost everything, we lost an engine, I lost both engines!” he said. His biggest fear was that he would slow down too much and stall the plane, but he seemed unsure of what he needed to do. He started ordering Rathore to try various last ditch methods to regain thrust, listing off one switch or setting after another — “Relight,” “Ignition override,” “Just anything!” But nothing worked. Descending low over the Lagos suburbs, Captain Waxtan fought to keep his plane from striking tall radio masts and multi-story apartment buildings that protruded up into his path, but his efforts were futile.

A sketch of the moment of impact. (Own work)

In the densely populated working class neighborhood of Iju-Ishaga, residents near the intersection of Okusanya and Popoola streets suddenly looked up to see an MD-83 falling almost silently out of the sky on top of them. With its engines stopped, the plane made little noise, and it arrived without warning. Flight 992 sliced the tops off several fruit trees before slamming into a three-story apartment block that was under construction, obliterating the top floor in a hail of flying masonry. The plane then crashed headlong into a printing press and two adjacent houses, igniting the fuel tanks and triggering a massive explosion. In an instant, half a city block was reduced to flaming rubble.

Crowds of people swarmed the crash site to see what had happened. The wreckage of an engine lies in the foreground. (news18.com)

The crash obliterated most of the plane and instantly killed everyone in the front section, but those at the back initially survived. Unfortunately, there was no time for them to escape; everyone who survived the impact quickly perished from smoke inhalation before any attempt could be made to open a door. Many residents of Iju-Ishaga had also been killed and injured; some managed to escape with their lives at the last second, but others were not so lucky. At least six people on the ground died in the crash, but the real toll might have been higher; some sources put the number as high as ten.

Immediately after the accident, crowds of onlookers swarmed the site to try to catch a glimpse of the carnage, making it difficult for firefighters to reach the blaze. Towering flames loomed over the neighborhood, accelerated by the vast volume of paper inside the printing press; emergency crews struggled for hours to get the fire under control. By the time they did so, little remained of the MD-83 or the printing press, except for the plane’s distinct T-shaped tail, which was left leaning askew atop a pile of blackened rubble. As crowds continued to gather at the crash site, the Nigerian government sent in the military to secure the area, leading to bloody clashes as soldiers beat people and fired tear gas to disperse the onlookers.

The crash left Nigeria in shock. At least 159 people were dead, the worst air disaster in the country in more than two decades. For a period of nearly six years between 2006 and 2012, there hadn’t been any major passenger airline crashes in Nigeria, leading people to believe that safety was improving. Instead, the crash of Dana Air flight 992 brought back relatively fresh memories of the first half of that decade, when Nigeria suffered four major air disasters in as many years.

In May 2002, EAS Airlines flight 4226, a BAC One-Eleven, overran the runway on takeoff from Kano and kicked up a cloud of dust, which was ingested into the engines. The engines subsequently failed and the plane crashed into a school and two mosques where prayers were in session, killing 71 of the 77 people on board as well as at least 30 on the ground.

In October 2005, Bellview Airlines flight 210, a Boeing 737–200, nosedived into the ground minutes after takeoff from Lagos, killing all 117 people on board. Investigators were unable to find the black boxes and couldn’t determine the cause, but they did discover plenty of circumstantial evidence, including that the pilot had recently gone back to work after not flying for 14 years; the aircraft was not airworthy; pilot workloads were excessive; and pages in the operations manual containing key safety information were blank.

Less than two months later, in December 2005, Sosoliso Airlines flight 1145, a McDonnell Douglas DC-9, crashed into a grass verge between the runway and taxiway in Port Harcourt while attempting a go around in bad weather. The plane broke into two pieces and burst into flames, killing 108 of the 110 passengers and crew.

And finally, in October 2006, ADC Airlines flight 53, a Boeing 737, stalled shortly after takeoff from Abuja after the pilots pulled up too steeply while trying to recover from wind shear. The plane rolled 90 degrees to the left and crashed into a corn field, killing 96 of the 105 people on board.

All of these crashes caused public confidence in Nigeria’s aviation system to plummet, and the government vowed to take action to improve safety. But while there had been some progress made since 2006, the findings of the investigation into Dana Air flight 992 would shatter that hope and prompt a new wave of badly-needed introspection.

Within hours of the crash, Nigeria’s Accident Investigation Bureau (AIB) launched an inquiry into the cause. However, they faced an immediate hurdle: due to the prolonged exposure to fire, the flight data recorder had been destroyed, preventing any detailed examination of the functioning of the engines over the course of the flight. However, the cockpit voice recorder was recovered intact and revealed much useful information. Investigators were shocked to discover that the left engine had in fact stopped responding to throttle commands within 17 minutes after takeoff, and the pilots did not even attempt to follow any of the appropriate procedures. They didn’t use checklists at all, repeatedly calling them complete without having read off a single item. They overflew several suitable airports where they could have made an emergency landing. The cockpit conversation was full of swearing, and the captain delayed making a mayday call because he was afraid of being investigated by the Nigerian Civil Aviation Authority, instead putting it on faith that they would make it to Lagos unharmed. He shouldn’t have tempted fate — when their second engine also failed, the pilots were wholly unprepared, having done nothing to ensure that their situation was stabilized. After that, by failing to use the double engine failure emergency checklist, they sealed their fate. Simulator testing showed that had the pilots followed the procedures in the checklist in order to optimize their glide, they could easily have reached the runway.

Part of a three story apartment building was reduced to rubble — thankfully, it was under construction at the time. (CNN)

Figuring out why the engines failed proved to be extremely difficult. Examination of the engines on-site confirmed that they were not generating power at the moment of impact, but after that, the trail of evidence effectively ended. The badly damaged engines were transported back to the Millennium Engine Associates facility in Miami for an initial teardown, where investigators observed the components of the fuel delivery system and conducted metallurgical tests on the various fracture points. Although there was damage to the secondary fuel manifold inlet tubes on both engines, no conclusive evidence that this occurred before the crash was found, and the AIB had the parts of the fuel manifolds transported back to Nigeria for a closer inspection. The left engine fuel manifold arrived normally, but to the AIB’s frustration, no further inspection of the right engine fuel manifold was possible because Millennium Engine Associates inexplicably failed to return it. With so little to go on, US and Nigerian investigators initially suspected that the pilots had somehow misused the fuel pumps and starved the engines of fuel.

The tail of the MD-83 is lifted out of the pile debris using a crane. (CNN)

Then, in October 2013, the AIB received a lucky break when one engine refused to respond to throttle inputs on another Dana Air MD-83. The pilots landed the plane without incident and the AIB disassembled the engine to examine its fuel system. They discovered that the secondary manifold inlet tube had sheared off at its connection point because the protective fairing around it had been installed incorrectly, compromising its aerodynamic shape. Hot air rushing through the engine caught the edge of the improperly attached fairing, causing it to act like a sail that constantly pulled the inlet tube sideways until it eventually broke. This failure was made possible because the manifold was not in compliance with the Pratt & Whitney service bulletin mandating that the original manifold assembly be replaced by a stronger version. And just like the failed engines on flight 992, this engine had recently been overhauled by Millennium Engine Associates, which had by now rebranded itself to Global Engine Maintenance, LLC.

A photo of the improperly installed inlet tube fairing on the Dana Air jet that made an emergency landing. (AIB)

This incident allowed investigators to realize that although there was no evidence of fatigue cracking on the secondary manifold inlet tube from flight 992’s left engine, that didn’t rule out the possibility that the inlet tube had failed in shear prior to the crash. The evidence left behind by a shear failure due to improper installation and a shear failure due to impact would have been all but identical. Although it was impossible to prove that this same mechanism had resulted in the failure of flight 992’s left engine, it nonetheless proved to be the most compelling theory. The right engine was a much greater mystery — after all, it had been brought into compliance with the service bulletin, so its inlet tube shouldn’t have failed in the same way. But because Millennium Engine Associates hadn’t returned the right engine’s secondary fuel manifold, the AIB couldn’t explain why it had stopped responding to throttle commands, except that the failure mechanism was probably similar to that of the left engine. However, this lack of certainty has led to some continued speculation that the problem with the right engine was actually caused by the pilots’ mismanagement of the fuel pumps, as some experts had initially suspected.

The plane burns after the crash. Note also the detached thrust reverser and an SUV amid the rubble. (CNN)

Curiously, the AIB had much more success trying to explain the seemingly inexplicable failings of the cockpit crew. Digging into the background of Captain Peter Waxtan, investigators found plenty of warning signs. The FAA had revoked his commercial pilot’s license in 2009, but Dana Air never found out about this because it never conducted a background check on him, even though it was required to do so under Nigerian law. But that was only the tip of the iceberg. The AIB was unable to find any record of the captain’s time flying for Falcon Airlines. His letters of recommendation were not signed by the people they were purportedly from. There were no records of any interviews, written tests, simulator evaluations, or indoctrination training prior to his being hired by Dana Air. His Nigerian pilot’s license had an NCAA stamp on it but was not signed. Dana Air’s quality control department was not involved in the hiring process, contradicting the official Dana Air operations manual. There was no record of either pilot having undergone crew resource management training, which was required by law. Nor was there any record of Dana Air’s chief pilot having received the mandatory indoctrination training to familiarize him with company policy. The scale of the problem was staggering; everywhere the AIB looked, they found more disturbing shortcomings.

Another angle of the removal of the tail section. (AIB)

There were also clear red flags after Captain Waxtan was hired. Comments left by instructors during his line training at Dana Air remarked that he didn’t adhere to company procedures and missed numerous checklists and callouts. There was no record showing that he had improved in these areas at all before being granted the rank of captain. How could Dana Air have ignored all the missing records and his poor performance and hired him anyway? As it turned out, this culture of reckless negligence was pervasive throughout every level of the company. Interviews with former pilots revealed that crews habitually failed to report defects in the technical logs, and that Dana Air management often forced pilots to fly unairworthy airplanes. In fact, the pilot of the MD-83 that suffered the engine malfunction in 2013 told the AIB that that plane had been struggling on several previous flights, but that he had been forced to keep flying it anyway. He asserted that other Dana Air planes had similar problems. As a result, the NCAA ordered that all Dana Air engines that had been overhauled by Millennium Engine Associates be overhauled again by an NCAA-approved engine shop.

The MD-83’s nose gear is pulled from the wreckage. (BAAA)

The Nigerian government didn’t wait for the AIB to release its findings before taking decisive action, however. Within days of the crash, Nigerian president Goodluck Jonathan vowed that no such crash would be allowed to happen again. He subsequently ordered the creation of a nine-person panel to review the safety of the entire Nigerian aviation system, independent of the probe into the Dana Air accident. Nigeria also grounded all McDonnell Douglas MD-80 series aircraft nationwide and revoked Dana Air’s operating license, ordering the airline to overhaul its safety regime in order to get it back. Dana Air was grounded for three months until it finally got its certificate revalidated in September 2012.

Over the course of its investigation, the AIB issued several additional safety recommendations, including that Dana Air conduct background checks when hiring foreign pilots; that new pilots fly with an experienced captain as an observer for their first 100 hours to familiarize them with company procedures; that the NCAA should not validate the license of a foreign pilot without all appropriate background checks having been conducted; that Pratt & Whitney establish a deadline by which engines must be brought into compliance with the 2003 service bulletin; that the JT8D secondary fuel manifold installation procedures be modified so that there is no possibility of incorrect assembly; that Dana Air ensure negative evaluations of trainee captains are resolved before granting them a promotion; and that the NCAA monitor foreign companies performing maintenance on Nigerian aircraft. On top of these, the independent advisory panel issued many broad recommendations of its own.

Another view of the wreckage apartment building. (BAAA)

The reforms that were implemented in the wake of the Dana Air crash do seem to have made a difference. In the nearly eight years since, Nigeria has not had a single major airline accident, in comparison to four in the previous eight-year period. But while this represents a major leap in safety in what used to be one of the most dangerous places to fly, there is still work to be done. Dana Air still flies today, and it is hardly what one would call a safe airline. The Nigerian press still frequently reports on near misses involving Nigerian airlines, including a bizarre 2018 incident in which a door fell off of a Dana Air jet on landing in Port Harcourt. Many systemic problems remain as well. For example, several years after the Dana Air crash, there was still no facility in all of West Africa capable of performing heavy maintenance on large jet aircraft. Airlines like Dana Air are to this day forced to outsource this work to sketchy foreign companies like Millennium Engine Associates, because it’s what they can afford. As the AIB learned the hard way, these companies also have little respect for African institutions — after all, why would Millennium do something so blatant as to withhold key pieces of evidence from Nigerian investigators? Did Millennium believe that they could get away with screwing over the AIB because there was nothing a relatively weak African air safety agency could do to stop them? Similarly, small African airlines should be wary of hiring Western pilots without extensive background checks. An American pilot like Peter Waxtan most likely would have preferred to work in his home country, and in fact he did so until his license was revoked, forcing him to seek employment somewhere with less rigorous oversight. Because Nigeria suffers from a shortage of qualified pilots, its airlines sometimes have no choice but to hire people like Waxtan, but they do so at their own risk.

A memorial was later erected at the crash site, featuring a list of the names of the victims as well as a sculpture of a Dana Air MD-83 crashing. (abusadiqu)

At the same time, it is important to remember that Waxtan was a victim of this tragedy too. He was not exactly the cream of the crop, but this doesn’t mean he deserved to die — for his own sake, the system should have weeded him out, but this system failed. A better airline might have been able to make a decent pilot out of him, but tragically, the culture at Dana Air actively exacerbated his most dangerous failings. He was also handed a plane that could scarcely have been called airworthy, which callously placed him in a situation that no pilot should ever have to face. At the very least, his story should serve as a cautionary tale for other airlines on a continent where the industry is still struggling to meet the level of safety that its growing middle class has begun to expect.

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Analyzer of plane crashes and author of upcoming book (soon™). Contact me via @Admiral_Cloudberg on Reddit or by email at kylanddempsey@gmail.com.