The crash of American Airlines flight 1420: Analysis

The crash of American Airlines flight 1420: Analysis

Image for postAmerican Airlines flight 1420 lies on the bank of the Arkansas River after the crash. Source: Tailstrike

On the 1st of June 1999, American Airlines flight 1420 attempted to land in Little Rock, Arkansas during a thunderstorm, only to slide off the end of the runway at more than 160 kilometers per hour. The MD-80 fell down an embankment and collided with the support structure of the runway approach lighting system, breaking the plane into three pieces and killing 11 of the 145 people on board. The National Transportation Safety Board?s report on the crash revealed that the pilots had been suffering from fatigue and were under pressure to land in bad conditions, resulting in mistakes that sent the plane off the runway ? and that a poorly designed runway environment ensured a fatal outcome.

American Airlines flight 1420 was a McDonnell-Douglas MD-82 operating a short domestic route from Dallas, Texas to Little Rock, Arkansas. In command of the flight were Captain Richard Buschmann, an extremely experienced pilot with more than 5,000 hours on this aircraft type; and First Officer Michael Origel, who was not new to flying but had only 182 hours on MD-80 series aircraft. The pair had flown together that day from Chicago to Salt Lake City and then to Dallas, arriving at Dallas Fort Worth International Airport at 8:10 p.m. after about 10 hours on duty. Due to bad weather in the region, delays were mounting. The flight to Dallas arrived 39 minutes late, and then the arrival of the plane scheduled to operate flight 1420 was severely delayed because of the weather conditions.

Image for postAn American Airlines McDonnell Douglas MD-82, and the routes flown that day by the pilots. Image source: Wikipedia

Pilots can only be on duty for a strictly limited number of hours before they must rest. Buschmann and Origel knew that if flight 1420 didn?t leave before 11:16 p.m., they would exceed these limits. Origel called the dispatcher and said that a different plane must be found or the flight should be cancelled. The dispatcher succeeded in arranging a new aircraft, but without much time to spare ? with 139 passengers and 6 crew on board, flight 1420 finally departed for Little Rock at 10:40 p.m., two hours and twelve minutes late.

14 minutes into the flight, the dispatcher informed the crew that thunderstorms in Little Rock could affect the landing, and suggested that they ?expedite? their arrival to get on the ground before the storms got any worse. A diversion was never considered.

Despite the impending bad weather at their destination, the pilots appeared to be in good spirits. At one point First Officer Origel said, ?There?s a moon out there. Or a space ship,? to which Captain Buschmann replied, ?Yeah, the mother ship.?

?Ha, got your Nikes on?? Origel joked.

Within a few minutes, however, the cockpit atmosphere took on a more serious tone. Using their on-board weather radar, the pilots could see thunderstorms approaching the airport from the northwest, and lightning flashed in the distance. Captain Buschmann commented, ?We got to get over there quick.? He then announced to the passengers that they would be descending soon, and that there was ?quite a light show off the left hand side of the aircraft.? However, on their radar the pilots could see a gap, which they referred to as the ?bowling alley,? that appeared to lead right up to the airport, potentially giving them an easy path down. Flanked by lightning, flight 1420 began its descent into Little Rock at 11:28 p.m.

The pilots completed the approach checklist, all the while monitoring the progress of the storm ? and the ?bowling alley,? which seemed to be holding.

?I think we?re gonna be okay ? right there,? said Origel, pointing out the lights of the city.

?Down the bowling alley,? said Buschmann.

?As my friends would say,? said Origel, ?California cool.?

?Peachy,? Buschmann replied with a chuckle.

At 11:34, the Little Rock approach controller informed flight 1420 that the wind speed at the airport was 28 knots out of the northwest, gusting to 44 knots. The active runway was aligned southwest to northeast, meaning that this was a significant crosswind. Captain Buschmann noted that a 28-knot crosswind was ?right near the limit.? American Airlines company policy prohibited pilots from landing in a crosswind greater than 30 knots when the runway was dry.

Origel noted that this was the dry runway limit, and asked Buschmann about the wet runway limit. Buschmann told him it was 20 knots. However, as far as they knew the runway was still dry.

At 11:39, the approach controller contacted flight 1420 and said, ?American 1420, uh, your equipment?s a lot better than what I have. How ?s the final for [runway] 22 left looking??

First Officer Origel replied, ?Okay, we can see the airport from here. We can barely make it out, but we should be able to make [runway] 22. Uh, that storm is moving this way like your radar says it is, but a little bit farther off than you thought.? The pilots believed they still had enough time to get on the ground before the full force of the storm reached the airport.

Image for postWeather radar overlaid on the positions of flight 1420 and the airport at 11:39:12. Image source: the NTSB

Moments later, the approach controller informed flight 1420 that the wind had shifted and the crosswind would have a tailwind component if they landed on runway 22. Immediately after this, the controller received and passed on a ?wind shear? alert warning of large differences in wind speed and direction within the airport boundaries.

In light of this new information, the pilots changed their approach plan, abandoning the landing on runway 22 left and choosing instead to land on 4 right? the same runway but from the other direction ? in order to land into the wind. However, intercepting the glide path into runway 4R required a turn back away from the airport, because they were currently too close to go straight in.

Image for postWeather radar overlaid on the positions of flight 1420 and the airport at 11:39:45. Image source: the NTSB

As they looped back to the southwest, First Officer Origel could sometimes see the runway, but Captain Buschmann could not. Buschmann asked Origel to keep the runway in sight and help guide him to it. Origel told the controller that they had the runway in sight, and the controller asked if they wanted to use the instrument landing system or ?shoot the visual approach.? The pilots decided to make a visual approach because they could see the runway and it would be faster.

But before long, shifting clouds got in the way of the visual approach. Captain Buschmann said, ?See, we?re losing it. I don?t think we can maintain visual.? First Officer Origel told the controller that there was a cloud between their position and the airport and that they would like to be guided onto an Instrument Landing System (ILS) approach instead. This would send the plane even farther away from the airport before coming back around.

Explaining his decision, Buschmann said, ?I hate droning around visual at night in weather without having some clue where I am.?

?Yeah,? said Origel, ?But the longer we go out here??

He left the sentence unfinished, but the implication was that a loop farther to the southwest of the airport would take them out of the bowling alley and into another cell of the storm. A moment later, he said, ?See how we?re going right into this crap??

By now, the full force of the storm was moving over Little Rock, and the bowling alley no longer led all the way to the airport. But the pilots couldn?t see this on their weather radar because the radar only shows the areas directly ahead of the plane, and they were facing away from the airport.

Image for postWeather radar overlaid on the positions of flight 1420 and the airport at 11:44:30. Image source: the NTSB

At 11:46, flight 1420 began to turn back toward Little Rock. The bowling alley was rapidly retreating.

?Aw, we?re going right into this,? said Buschmann.

?American fourteen twenty, right now we have uh, heavy rain on the airport,? said the controller, adding that the latest weather report was out of date and that visibility was down to 3,000 feet. The report of rain meant that the runway was now wet, reducing the maximum allowable crosswind at landing to 20 knots. However, with visibility less than 4,000 feet, this limit further decreased to 15 knots.

Image for postWeather radar overlaid on the positions of flight 1420 and the airport at 11:46:52. Image source: the NTSB

16 seconds later, the controller informed flight 1420 that the wind was blowing from the north-northwest (350 degrees) at 30 knots, gusting to 45 knots. This was above American Airlines? specified crosswind landing limit on a wet runway. But when Origel read back the transmission, he accidentally said ?zero three zero? degrees instead of ?three five zero.? Had the wind direction actually been 030? it would have been a headwind, not a crosswind, and landing would have been allowed.

?Can we land?? Buschmann asked. ?3,000 RVR [Runway Visibility Range], we can?t land on that.?

Origel pointed out that the minimum visibility for landing on runway 4 right was 2,400 feet, but not that they were over the crosswind limit, probably because he misheard the wind direction. Now lined up with the runway, the pilots continued the approach, even though American Airlines policy said they weren?t allowed to land.

Now on final approach, the pilots started the landing checklist, getting as far as lowering the landing gear before the controller interrupted them with news of more wind shear alerts. The pilots resumed the checklist, completing all the items, except for one: they forgot to arm the spoilers.

Ground spoilers are flaps on the top of the wings that pop up on landing to reduce lift and provide downforce. The spoilers push the plane down and transfer its weight onto the landing gear, increasing the effectiveness of the brakes. The spoilers are normally armed during final approach so that they deploy automatically on touchdown; if they are not deployed, braking power could be reduced by more than 80%. When the pilots forgot to arm the spoilers, they set themselves up for disaster.

Unaware of their error, the pilots of flight 1420 plowed ahead into the most violent part of the thunderstorm. And yet, neither pilot mentioned the effect of wind or the rain during the final approach. More weather reports indicating high crosswinds came and went with no mention of company limits. Violent winds jolted the plane as it descended, and almost continuous lightning illuminated the heart of the storm. One passenger later recalled that he believed they would crash if the pilots tried to land in this weather.

At 11:49, descending through an altitude of 880 feet above ground level, Captain Buschmann said, ?This is a can of worms!? But there was no discussion of making a missed approach.

Moments later, the pilots saw that the powerful winds were pushing them to the right of the runway centerline. ?Aw shit, we?re off course,? someone said, possibly Buschmann.

?We?re way off,? said Origel. Flight 1420 descended through 460 feet ? decision height. Now they were committed to landing no matter what.

Image for postWeather radar overlaid on the positions of flight 1420 and the airport at 11:49:12. Image source: the NTSB

The pilots managed to wrestle the plane in line with the runway at the last second, coming in steep while ?sink rate? warnings blared in the cockpit. At 11:50 and 20 seconds, flight 1420 touched down extremely hard on runway 4 right. The spoilers did not deploy, and the pilots did not manually deploy them.

?We?re down,? said First Officer Origel. ?We?re sliding!?

Image for postNTSB animation of the landing sequence. Video source: the NTSB

Captain Buschmann uttered a string of expletives. The plane yawed hard as the crosswind hit, sending it sliding almost sideways down the runway. The pilots deployed the thrust reversers and hammered the brakes, but they were all but useless without the spoilers pressing the wheels onto the tarmac. The thrust reversers caused further problems; by disrupting the airflow past the rudder, they reduced the pilots? directional control of the plane. Buschmann and Origel never selected full reverse power and cancelled the reverse thrust after six seconds. The totally ineffectual brakes were now the only means with which to stop the aircraft. This was not enough. The MD-80 hurtled toward the end of the runway, yawing wildly back and forth, before running off onto the grass at 160kph.

Flight 1420 bounced across the grass overrun area at high speed, striking part of the ILS localizer. The MD-80 then skidded over the edge of a 7.5-meter embankment and slammed into the elevated metal pier supporting the approach lighting system for runway 22L, which pierced the cockpit and tore away the left wall of the first class cabin from bulkhead to bulkhead. The plane then crashed to the ground and broke into three pieces, come to rest tangled amid the twisted wreckage of the approach lighting pier.

Image for postMy original drawing of the moment of impact.

The penetration of the pier into the cockpit and first class cabin instantly killed Captain Buschmann and one passenger. A further three passengers died when rows 17 and 18 were ejected from the plane and into a fire during the breakup. But the danger was far from over: almost as soon as the plane came to rest, flames erupted at the front of the broken tail section, which contained about half the passengers. As people queued for the exits, smoke poured into the cabin, sending passengers frantically fleeing through the darkness and driving rain. Most escaped through the overwing emergency exits and through gaps in the fuselage, but four were unable to get out in time and perished from smoke inhalation.

In the cockpit, First Officer Origel had survived the crash, but his leg was trapped and broken in three places. Captain Buschmann?s blood soaked the instrument panel. In the minutes after the crash, Origel used his cell phone to call the American Airlines operations center to inform them of the crash, then called his wife ? all before the first rescuers had even arrived at the scene.

Image for postWreckage of the plane and the lighting pier after the crash. Image source: Wikipedia

As soon as the controllers realized that flight 1420 was missing, they alerted the airport?s emergency services and told them that an MD-80 was ?down on runway 4R.? But the controller didn?t specify which end of the runway, and fire trucks initially went to the approach end, assuming the plane had crashed short of the runway. When they failed to find it, they began to work their way up the runway, moving slowly due to the fear of running over possible survivors in the low visibility conditions. Only after some time had passed did the controller inform them that the crash was at the departure end of the runway. When the firefighters finally arrived, they discovered that the plane had fallen down a steep embankment, forcing the trucks to backtrack onto the perimeter road and unlock a closed gate to reach the wreckage. When they finally arrived almost 18 minutes after the crash, most of the passengers had already escaped and were huddled near the plane. With the help of the rain, the firefighters quickly extinguished the fire, then entered the plane and started working to free those who were trapped. First Officer Origel proved difficult to extract; it took an hour and a half to cut away the debris that had pinned him in his seat, but he ultimately survived.

Image for postLocations of fatalities and injuries. Image source: the NTSB

In the week after the crash, two more passengers died of their injuries, bringing the death toll to 11, including Captain Buschmann and 10 passengers. 110 others were injured. This was American Airlines? third major accident and second fatal accident in less than five years.

Investigators ended up delving deeply into the actions of the pilots, the airline?s training regime, and the behavior of pilots around the United States. What they found was that on the surface level, the sole cause of the accident was the pilots? failure to arm the spoilers. Had they done so, the plane would not have crashed. But the more interesting question was why they forgot this critical step. In fact, the origin of this failure was rooted in the extreme workload that the pilots faced while trying to land in the midst of an intense thunderstorm. They changed their approach plan twice, fought against powerful winds, and struggled to see the runway through shifting clouds. Amid the constant flurry of problems demanding their attention, from the position of the storms to the visibility to the direction of the wind, it proved difficult to do everything. Considering that the pilots were near the edge of their duty limits and had been awake for 16 hours, fatigue had also begun to set in, and yawning could be heard on the cockpit voice recording. Working in a highly stressful environment and up past their bedtimes, it was almost inevitable that the pilots would miss something important. Also contributing to the failure was the ambiguity surrounding whose job it was to actually pull the spoiler lever.

Image for postThe left front portion of the fuselage, where the lighting pier ripped into the plane. Image source: Wikipedia

Investigators also had to ask why the pilots ever attempted to land in such a violent storm in the first place. What they discovered was that doing so was not particularly unusual. Although pilots are trained not fly into thunderstorms, a 1999 study by the Massachusetts Institute of Technology found that when encountering a thunderstorm rated ?strong,? ?very strong,? or ?intense? while more than 25 kilometers from their destination, 26% of pilots chose to fly through it. That number went up to 90% when encountering such a storm within 25 kilometers of the destination airport, especially when other planes had flown through the storm already, or when the flight was running late. Virtually every pilot chose to fly through potentially dangerous thunderstorms when avoiding them might jeopardize an on-time arrival! This presented an industry-wide problem: pilots were under pressure to keep flights on schedule, and when weather turned foul, they tended to err on the side of timeliness rather than safety. In the airline industry, this is known as ?get-there-itis,? a condition that sets in when a crew just wants to ?get there? and starts making increasingly risky moves to reach their destination on time. Running late and suffering from fatigue, the pilots of flight 1420 succumbed to get-there-itis and started making more and more mistakes as the flight went on. They missed callouts, didn?t finish checklists, misheard weather reports, and used non-standard terminology. They chose to continue an approach that company procedures said should be abandoned, and forgot to arm the spoilers. Buschmann and Origel had tragically fallen victim to a system that normalized getting to the destination on time at any cost.

Image for postThe left front portion of the fuselage, where the lighting pier ripped into the plane. Image source: the New York Daily News

Unfortunately, after the crash First Officer Origel wiped away any good will he might have received for being put under such pressure. He testified that he had called for the spoilers to be armed while doing the landing checklist, and that Captain Buschmann must not have pulled the lever. But the cockpit voice recording proved that this was not the case; neither pilot ever mentioned the spoilers. He also claimed that he hesitantly told Captain Buschmann that they should make a missed approach, but he then saw that they appeared to be back on course, leading him to change his mind. The cockpit voice recording did not reveal any evidence that this occurred either. Suffering from guilt over his role in the crash, he resorted to lies and half-truths in an effort to deflect blame onto his dead captain, instead of owning up to his mistakes.

Image for postInside the plane after the crash. Image source: Mohammed Gari

There were more mistakes that contributed to the outcome as well. After touchdown, the pilots failed to notice the lack of spoilers, failed to make full use of the thrust reversers (at the expense of directional control), and did not brake as aggressively as they could have. But the cause of the fatalities was not so much the runway overrun itself, but the overrun environment. Due to the presence of the Arkansas River just a short distance off the end of the runway, there was not much of a run-out area before the embankment dropping down the flood plain. Moreover, some of the worst damage occurred during the collision with the approach lighting pier, which severely compromised the aircraft?s structure and outright killed three people as it sliced through the plane. The National Transportation Safety Board had previously recommended that structures in runway overrun areas be made frangible ? that is, easily broken when struck by a plane. But while a nationwide program to improve the frangibility of such structures was underway at the time, the process was extremely slow, and the Federal Aviation Administration believed that many objects couldn?t feasibly be made frangible. The NTSB found this regrettable. Had the pier simply snapped off on impact, there would have been fewer injuries and deaths.

Image for postAnother aerial view of the plane. Original image source is unclear.

In the aftermath of the Little Rock crash and a subsequent non-fatal runway overrun in Palm Springs, American Airlines ended up revising its training around approaches and landings, especially in poor weather conditions and in situations where the spoilers don?t deploy. It also updated its flight operations manual to reflect the changes and made it clear that a go-around must be performed if an approach is not stabilized by 1,000 feet above ground level.

Furthermore, the NTSB made a large number of recommendations to prevent such an accident from happening again. These recommendations included that both crew members verbally confirm that the spoilers are armed; that pilots verbally confirm whether spoilers have in fact deployed after touchdown; that MD-80 pilots be instructed to use a lower reverse thrust power setting that doesn?t interfere with directional control on slippery runways; that automatic braking be used when landing on wet runways; that research be conducted to find ways to reduce thunderstorm penetrations; that air traffic control towers upgrade their weather radar to a new minimum standard; that controllers give firefighters all known information about the location of a crash without being asked; that research be conducted into crash-detection technologies that could reduce response times; that a review be undertaken to find more structures near runways that could be made frangible; and that the FAA provide more oversight staff for American Airlines? training program, along with numerous other more obscure points. The NTSB also re-issued an earlier recommendation calling for new flight duty time limits that take into account the scientific consensus surrounding fatigue and circadian rhythms.

Image for postA comparison of runway 22L/4R in 1994 and 2018. Imagery source: Google Earth

Today, much has changed both nationwide and in Little Rock. Runway 4R now has a much longer overrun area, and in 2001 Little Rock National Airport installed an Engineered Materials Arrestor System, an advanced installation that acts like a runaway truck ramp for planes. With these improvements, no one should die in a runway overrun at Little Rock ever again. In fact, while there have been many runway overruns since 1999, American Airlines flight 1420 was the last overrun in the United States that resulted in the death of anyone on board the plane.

The changes to duty time limits that the NTSB had wanted since 1990, and reiterated after the Little Rock crash, have since been implemented. Weather forecasts and radar are much improved. Today it is easier to avoid thunderstorms and pilots are more aware of the dangers. The result is a safer sky ? thanks in part to lessons learned after the crash of flight 1420, which was not only America?s last fatal runway overrun, but also the last fatal weather-related crash of an American airliner. While we cannot be sure that serious accidents of these types are gone for good, 20 years without them is a milestone to be celebrated.

_____________________________________________________________

Join the discussion of this article on Reddit!

Visit reddit.com/r/admiralcloudberg to read 100+ similar articles.

No Responses

Write a response