Like it or not, if you are flying a jet your life is filled with numbers. Airspeed, altitude, limitations, performance, to name just a few examples. The problem for pilots not comfortable with numbers is that you can spend so much of your time well away from the margins of those numbers, that when you are faced with getting to the edge, you may be inclined to “call it good” rather than really think about them. Take, for example, landing a Boeing 737 in rain, with a tailwind, with a windshear, when the margin for error is just 245 feet.
— James Albright
Updated:
2025--
Southwest 728
(from NTSB Operational Factors)
First officer: “You want to call it good?”
Captain: “Yeah.”
As we like to say in the Air Force, BLUF, Bottom Line Up Front: the crew failed to stop on the runway because they decided to land when they shouldn’t have, because they landed long, and because they failed to use the braking capability they had. The runway’s Engineered Materials Arresting System (EMAS) saved them, and it looks like the cosmetic changes to Southwest Airlines procedures will allow them to carry on as before. We’ve seen this many times from Southwest.
Southwest Airlines has a long history of flying unstable approaches, landing long, and of pilots not serious about using all available means to stop the airplane in the correct manner. Unlike many Southwest Airlines approach and landing incidents, the pilots here flew a stable approach. But their decision making before the landing and the execution of the landing itself were not good. The NTSB got their report mostly right, but I think their statement of probable causes misses something important: Southwest Airlines pilot culture.
Date: December 6, 2018
Time: 0902 Local
Aircraft: Boeing 737-7H4
Operator: Southwest Airlines
Registration: N752SW
Fatalities: 0 / 117
Aircraft damage: Minor
Destination airport: Bob Hope Airport (KBUR), Burbank, CA
1
All about numbers
At the time, the captain, age 58, was highly experienced with 15,410 total hours, 11,350 hours in type, and 4,995 hours PIC. He had flown into KBUR between 80 and 100 times. The copilot, just 5 years younger, had 10,855 total hours, exactly 5,000 hours in type. He had flown into KBUR over 100 times. [Final Report, p. 10] The captain was a retired U.S. Marine Corps pilot who had flown and instructed in EA-6B and T-2 aircraft. The first officer was a retired Air Force pilot who had flown KC-135, U-2, and T-38 aircraft. Neither pilot had any records of accidents, incidents, or enforcement actions. [Operational Factors, pp. 12 – 13]
The well-qualified captain was the pilot flying, the aircraft was well-equipped with an excellent autobrakes system, the company provided a very good Performance Weight and Balance (PWB) system that gave them the information they needed for the challenge to come. Runway 08 was 5,802 feet in length, one of the shortest runways used by SWA, but well within the airplane’s capability.
The flight departed Metropolitan Oakland International Airport (KOAK) about 0810. The crew received Automatic Terminal Information System (ATIS) Hotel, which was issued at 0753: Winds 280/5, visibility 1-1/4 miles in heavy rain and mist, ceiling broken clouds at 1,100 ft Above Ground Level (AGL). The crew requested and received a Performance-Based Weather (PWB) report, which was based on the most recent METAR, estimated aircraft landing weight, flaps setting, and runway conditions. The most recent METAR agreed with the ATIS except winds were reported to be 290/5. The PWB indicated they had a stopping margin of 245 feet. The captain said he had never seen a stopping margin this low, and the first officer said it concerned him.
Personal note: I’ve used 1,000 feet as my personal limit for stopping margins. If the runway is 5,802 feet and the numbers say I need 5,557 feet of it, provided I do everything right, I decide that I need someplace else to land. I’ve done this several times in my career. You may argue that I would never survive as an airline pilot, and you might be right.
Burbank ILS Z Rwy 8 (NTSB Operational factors, fig. 1)
The crew was cleared for the ILS Z Rwy 8 approach. At 0855 they were advised that a 15-knot loss of airspeed on final was reported about 10 minutes earlier and that a corporate jet had just conducted a go around because of the wind. The crew configured with Flaps 40 and slowed to between 133 and 136 knots. VREF was 126 knots and VTARGET was 131 knots. They were advised of medium to heavy precipitation over the airport and that the winds were 270 at 11 knots. The interviews indicated that they discussed the final wind they received, 270° at 11 knots, and agreed that the resulting tailwind component was within the limit of 10 knots shown in the Limitations section of the SWA B737NG Aircraft Operating Manual (AOM). [Operational Factors, pp. 6 – 7]
This is a minor point: a wind from 270° at 11 knots on a runway of 079° is a 10.8 knot tailwind. As a rule of thumb, any wind direction greater than 75 ° produces a component that is 100% of the total wind strength. The published tailwind limit of the airplane is 10 knots.
SThe controller stated that the wind was from 270° at 11 knots. At 0901:52, the first officer stated, “we got eleven knots. You want to call it good?” The captain replied, “yeah.”
[Final Report, p. 8]
This is a major point: their 245-foot stopping margin was based on a 5-knot tailwind and now they have a 10 or 11 knot tailwind.
They broke out of the weather around 400 feet AGL. The captain said the glide slope was “right on.” The first officer said they were slightly high and then slightly low. The captain said they were between 131 and 133 knots. Their target speed was 131 knots. The NTSB performance study says they crossed the threshold at 137 knots. The captain believed they crossed the threshold between 30 and 50 feet, the performance study says 54 feet. The captain believes they touched down between 1300 and 1500 feet. The performance study says 2,504 feet, which agrees with the tower controller’s observation. [Operational Factors, pp. 7 – 8]
Very few pilots realize just how far behind their sight picture the wheels touch on a jet this size while on a 3° glidepath to landing. I believe the difference is about 400 feet, in other words, the wheels touch 400 feet short of where you think they are as you touchdown. How do I know this? See: Aim Point vs. Touchdown Point.
In his statement, the FO said that the speedbrakes and thrust reversers were deployed immediately on touchdown. He reported that the brake anti-skid system began to cycle, and the airplane did not slow appreciably at first. The captain stated that after touchdown, he used maximum reverse thrust and heard and felt chattering of the brakes through the brake pedals. He verified that the speedbrake handle was extended and “started blending in manual brakes after that.” He stated that with thrust reverse and autobrakes, the airplane did not feel like it was slowing. It then started to slow, but then deceleration decreased. As the airplane passed the intersection of runway 15/33 (about 3765 ft. from the runway 08 threshold) he became concerned about stopping. He stated that on a dry day, you could stow the thrust reversers and ease off the brakes at that point. He guessed that the airplane was at 70-80 knots at this point, faster than on a dry day. As they approached the final 1000-500 feet of the runway, the deceleration slowed markedly. He saw the large intersection where taxiway D1 intersected with the runway (about 5340 feet from the runway threshold) and thought he might be able to make a turn off the runway there, but as he tried to turn using left rudder and the tiller, he didn’t feel the airplane was responding. He felt the nosewheel was just skidding. He stated he then straightened out the nosewheel so they would not enter the EMAS with the nosewheel cocked sideways. The airplane entered the EMAS at a speed of about 10-15 knots and was quickly brought to a stop. The thrust reversers were still engaged upon entry.
[Operational Factors, pp. 7 – 8]
In this event, he started manual braking probably 3-4 seconds after touchdown, after all three landing gears were down and the reversers had been deployed.
[Interview Summaries, Captain, p. 6]
My concern here is the captain’s statement that he “started blending in manual brakes” very soon after landing. The PWB was based on maximum autobrakes [Final Report, p. 7]. Assuming they were set that way, there is nothing the pilot could have done to improve on the autobrakes and “blending in” would have been the wrong answer in any case.
You might be wondering about stable approach criteria and the requirement to go around. The captain appears to have flown a stable approach. They were on course, on glidepath, and within airspeed tolerances. The NTSB report mentions that a go around would be required under SWA procedures:
- The approach does not meet stabilized approach criteria
- The pilot determines that a landing in the touchdown zone cannot be safely accomplished because of one or both of the following:
- The required descent or maneuvering will exceed the stabilized approach criteria.
- The aircraft touches down beyond 1500 ft. with an insufficient PWB System-computed stopping margin.
[Operational Factors, p. 27]
I believe stabilized approach criteria were met, but as they crossed the runway threshold the captain should have realized he would probably not be able to land in the touchdown zone and should have gone around. Furthermore, after he made the decision to proceed with the touchdown, he should have realized everything from that point on had to be executed perfectly. “Blending in” manual braking was a less than perfect action.
2
EMAS to the rescue or an excuse to look the other way?
The airplane came to rest about 144 feet past the departure end of Runway 08 and 71 feet into the EMAS. The damage to the aircraft was classified as “minor” and nobody was hurt. In a bit of an irony:
[The captain] saw the large area at intersection D1 thought he might be able to make the turnoff at D1. He tried to use the left rudder and tiller to turn the aircraft but didn’t feel like it was responding, so he continued into the EMAS.
[Interview Summaries, p. 4]
Simulation results indicate that the airplane might have stopped before entering the EMAS if it had remained on the grooved runway surface instead of deviating to the left off of this surface, which resulted in a significant loss of friction.
[Performance Study, p. 62]
Ground track (NTSB Performance Study, fig. 2b)
The pilots, as required, had their “quals pulled,” during the investigation.
The FAA’s Supervisory Principal Operations Inspector (SPOI) was interviewed by a team of NTSB and FAA investigators. At one point one of the FAA inspectors asked about SWA’s acceptance of using zero stopping margin, the questioner saying, “That doesn’t look good to us as the FAA.” The SPOI answered:
“Well, regulatory wise they can do that. The regulation says, you know, as long as you have these 15, 115 percent all the requirements for planning the approach and all the other stuff. As long as you stop that airplane within the confines of the runway that is legal.
[FAA Interview, pp. 22 -23]
The SPOI noted that “granted they’ve used for years 2,000 feet because I think they weren’t quite as confident,” but the questioners didn’t press on this issue. When asked about the pilots, he said “there might be some judgment issues here,” but, “I felt that this was going to be difficult to actually identify a root cause, why did they do what they did [ . . . ] I’d rather see it be a robust where they give these training, put them in the simulator, their annual qualification program.”
Both pilots were sent through their annual qualification program and 3 days of flying with an Aircrew Program Designee (APD), appointed by the FAA. The first officer passed his 3 days of operational flying with the APD. The captain passed his simulator training but was flagged by the APD for “judgement capability, decision making capabilities.” The captain was sent back for “a more robust training program that included more information and more training on decision making, judgment.” He passed it the second time through. [FAA Interview, pp. 26 – 27]
3
Probable Cause (NTSB)
The National Transportation Safety Board determines the probable cause(s) of this incident to be:
(1) The flight crewmembers’ decision, due to plan continuation bias, to continue the approach despite indications of windshear and a higher-than-expected tailwind and (2) the flight crew’s misperception of the airplane’s touchdown point, which was farther down the runway than the crew assumed because of the faster-than-expected groundspeed. Contributing to the accident was Southwest Airlines’ lack of guidance to prompt flight crews to reassess operator-provided landing data when arrival weather conditions differ from those used in the original landing data calculation.
[Final Report, p. 6]
4
Probable Cause (My opinion)
The direct cause of this incident was indeed the flight crewmember’s decision to continue the approach, though I am not sure it was continuation bias. I do think the captain misperceived his touchdown point, but I don’t think it was because of the higher groundspeed. I do think Southwest guidance is a problem, but I think it is worse than that.
Continuation Bias?
Yes, but not just on this incident. I think the litany of Southwest Airlines incidents over the years shows a tendency of their pilots refusing to believe the approach at hand is unsalvageable. If anything, it is a “bias of hubris.” The pilots in many of these incidents seem to have an unjustified pride or presumption that they are not bound by the limitations that other pilots face. Not all Southwest pilots, of course. But we have names and dates of those who have this bias of hubris.
Misperceived touchdown point?
Yes, this captain didn’t realize that what he was looking at from his seat in the cockpit did not reflect where his main landing gear were touching down. But this is an issue for very many pilots of large aircraft. See: Aim Point vs. Touchdown Point.
Reassess landing data?
It is another irony in this case study that the NTSB cites SWA for failing to prompt their crews to reassess landing data when conditions have changed. Twelve years before this incident, another Southwest Airlines flight prompted industry-wide changes on this front: Case Study Southwest Airlines 1248. That further prompted Safety Alert for Operators (SAFO) 06012, Landing Performance Assessments at Time of Arrival (Turbojets). A year after SWA 728, that SAFO was updated with SAFO 19001.
The root cause
In my opinion, many Southwest Airlines incidents indicate some of their pilots ignore Standard Operating Procedures when convenient and this suggests they are flying as if they know better than their airline and the rest of us professional pilots. They are better than us. The airline has failed to instill the importance of SOPs in their pilots and has failed to exercise adequate oversight to ensure compliance.
I offer as evidence the following:
2000 Mar 5, SWA 1455, Case Study: Southwest Airlines 1455
2005 Dec 8, SWA 1248, Case Study Southwest Airlines 1248
2013 Jul 22, SWA 345, Case Study Southwest Airlines 345
There are also four other events that are in the midst of what might be a nefarious coverup designed to save the airline, or it just might be that the airline, the FAA, and the NTSB can’t be bothered:
2024, Mar 23, SWA 147, which came within 100 feet of the ground and 1,400 feet right of the runway, according to the airport’s Falcon Surface Monitoring System. News reports highlight the fact the airplane was heading for the control tower and came within 67 feet after it was sent around by the tower controller. There were 153 people on the airplane and certainly many in the tower. Nobody seems to have noticed that the airplane was headed right for the terminal.
2024, Apr 11, SWA 2786, which came within 400 feet of the water during a 4,000 feet per minute plunge during an approach to Lihue, Hawaii. We hear only that the aircraft was being flown by a “less-experience first officer” before the captain intervened, and that the FAA and the airline are investigating. Here we are more than a year later, and we’ve not heard a peep out of the airline or the FAA.
2024, Jun 19, SWA 4069, which came within 525 feet above the ground, 9 miles from the airport, on approach to will Rogers World Airport. An air traffic controller contacted the crew, asking, “Southwest 4069, low altitude alert. You good out there?” The pilot answered, almost nonchalantly, “Yeah, we’re going around.” Nine miles from the airport, no harm, no foul, no explanations. This was June of last year.
2024, Jul 14, SWA 425, which came within 150 feet of the water, more than 4 miles from the runway at Tampa, Florida. From news reports: “The Federal Aviation Administration (FAA) is investigating the incident as part of a broader review of multiple safety events involving Southwest Airlines.”
In short, this case of Southwest Airlines Flight 728, and the seven others I’ve listed all point to a problem with their pilot culture. Some of the finest pilots I know fly for Southwest. But there are enough bad pilots that spoil the airline for the others. And the airline has failed to bring everyone up to the level of the best. The airline, as a result, sinks to the level of the worst.
References
(Source material)
Aircraft Performance Study, DCA19IA036, October 29, 2020
Aviation Investigation Final Report, DCA19IA036, Runway Excursion, N752SW, Burbank, California, December 6, 2018
FAA Interview, Operational Factors / Human Performance, DCA19IA036, June 24, 2020
Interview Summaries, Operational Factors / Human Performance, DCA19IA036, December 7, 2020
Operational Factors / Human Performance, NTSB Group Co-Chairman’s Factual Report, DCA19IA036, December 7, 2020
Safety Alert for Operators (SAFO) 06012, Landing Performance Assessments at Time of Arrival (Turbojets), Federal Aviation Administration, 8/31/06.
Safety Alert for Operators (SAFO) 19001, Landing Performance Assessments at Time of Arrival, Federal Aviation Administration, 3/11/19.