You begin your approach to a 10,300-foot runway with ATIS reporting 10-knot winds and visibility of 3 miles with thunderstorms in the area. You anticipate that the runway will be wet and set autobrakes to 3. The pilot flying of a large airliner calls for the approach checklist with flaps at 25 degrees for a target speed of 154 kt, but does not fly the approach precisely on glide slope or speed. Per the landing checklist, he selects idle reverse thrust instead of full reverse, which would provide more drag after touchdown on a wet runway, but you fail to advise this setting.
On short final, with the aircraft above the glide path and crossing the threshold at a very quick 170 kts, a torrential downpour obscures sight of the runway and you order a go-around. The pilot flying pushes the thrust levers forward but does not press the takeoff/go-around button. With a 600 fpm sink rate, the aircraft touches down about 3,000 feet past the threshold, so you change your mind and yank the thrust levers to idle, reducing speed to 140 kts. However, the delay between the landing gear touchdown and idle selection has disengaged autobraking, and the aircraft continues to rapidly advance down the wet runway. Both pilots apply maximum braking to little effect and the aircraft passes the end of the runway at speed, colliding with an ILS antenna, collapsing the landing gear, and sliding to a stop about 700 feet later. Thankfully no one is hurt, but the aircraft is substantially damaged.
The above scenario, condensed from a Eurocontrol SKYbrary.info article, illustrates how quickly a runway excursion can occur—and some of the human factors that contributed to the result. A 2022 Flight Safety Foundation (FSF) report noted that runway excursions were cited as the most common cause of airliner accidents from 2017-2021, and the National Business Aviation Association (NBAA) recently published a 25-page document titled, “Reducing Runway Excursions in Business Aviation.”
Runway excursions are an ongoing hot topic for many aviation organizations, and FlightSafety International (FSI) has been using real-world insights from flight operational quality assurance (FOQA) data and simulator studies to weave runway excursion awareness into pilot training.
“If you can reduce the runway excursion risk through focused training and educate crew members on the importance of the techniques to prevent runway excursions, then you dramatically improve safety,” said Richard Meikle, FSI executive vice president of operations and safety.
Runway Excursions: Energy Management Failures
When FlightSafety entered into a partnership with GE Aerospace in 2021 to glean insights from real-world FOQA data, near-event runway excursions popped up with unsettling frequency. The data showed thousands of near events with aircraft slowing to turnoff speed with less than 100 feet of runway remaining, and a significant number with only 10 feet remaining.
Meikle, himself a corporate pilot and FlightSafety customer for 25 years before joining the company in 2020, says that the key to avoiding runway excursions on landing is precision delivery of the aircraft to the correct touchdown point and carefully managing the aircraft’s energy.
“Energy management keeps the airplane on the pavement,” said Meikle. “Runway excursions are often the result of the aircraft landing too fast or too long with the same amount of energy needed if they had touched down much earlier.”
The best practice is to go-around if the approach is not stabilized within 1,000 feet of the runway, but industry data shows that only about three percent of unstable approaches result in a go-around. Instead, pilots try to salvage unstable approaches. In good weather with long, dry runways, they are often successful, however if one of these factors turns unfavorable, the likelihood of an excursion increases.
“The GE Aerospace data has given us great insight to stable approach criteria, instability on final, and other factors that can contribute to runway excursions,” said Meikle. “There’s a direct correlation between threshold crossing height and touchdown point, and the data has shown that pilots trying to get a smooth landing by floating doesn’t always yield that result, however, in every case doing so erode safety margins.”
According to Meikle, another factor that “popped up quickly in the data” was the effect that displaced thresholds can have in contributing to runway excursions. “Displaced thresholds present a visual challenge. They cause an optical illusion that’s harder to judge… The arrival path to the runway also makes a big difference—flying a straight-in instrument approach is far more likely to have a stable approach than if you do some sort of maneuver to the runway. Even a traffic pattern increases the rate of unstable approach over a straight-in instrument approach.”
In February 2022, FSI rolled out the first “spotlight” to focus on runway excursion prevention in every fixed-wing initial or recurrent course. These consisted of a 15 to 20-minute debrief at the end of the first simulator session and included information on the top 10 airports where excursions are most likely to occur.
The runway excursion spotlights continued through the first quarter of 2023 when the spotlights changed to pilots’ delayed reaction to TAWS warnings, but Meikle says runway incursion awareness is still discussed when appropriate and will return with updated material as a revamped spotlight in the future given the continuing trend in the industry.
The Psychology of the Go-Around
Meikle says that while the go-around is a normal maneuver practiced during initial and recurrent training, pilots often hesitate to initiate or complete a go-around— even when they recognize an unstable approach. Internal and external pressures often play a part when pilots try to salvage unstable approaches, and often their decisions are seemingly reinforced as correct when the plane lands without reportable incident. Only when some unforeseen or forgotten element results in a runway excursion does the pilot conceded they should have gone around.
FlightSafety recently chartered a study conducted by the Presage Group that focused on pilots’ ability to assess go-around decision-making during environmental instability. Pilots used Gulfstream 500/600 simulators to fly a series of approaches in various conditions. Some were in normal conditions not requiring go-arounds, some included very minor variations, and some presented environmental challenges. After the study was completed, FSI and Presage jointly developed go-around course content and scenarios as an optional add-on course with ground school and simulator time.
“Go-around decision-making is all about how the pilots operate the aircraft,” said Meikle. “It’s not something where you could just say, watch this, read this, and you’ve got it. You really have to get thrown into those scenarios to practice decision-making skills. It’s easy to decide to go around if you see another airplane on the runway, but it’s a whole other matter to recognize the need to go around despite having thoughts you can save the approach prior to touchdown.”