Seminar Examines the Causes of Runway Excursions
While the high-speed runway excursions that result in crumpled aircraft may make the evening news, they are only the most visible examples of what is becoming a growing trend, said Paul Ratté, aviation safety programs director at USAIG. Last month the insurance provider sponsored a safety seminar along with NBAA and the Westchester Aviation Association at a hotel in Westchester County, New York; it will be repeated on June 20 in Connecticut at Key Air’s Waterbury-Oxford Airport facility.
According to statistics from the Flight Safety Foundation, in the 15-year span from 1995 to 2010 operators of jets and turboprops with an mtow of more than 12,500 pounds amassed more than 650 runway excursion accidents worldwide, including 65 fatal crashes that claimed the lives of 1,121 people. Although runway incursions are far deadlier (55 percent of the incursion accidents during that same span resulted in fatalities) they result in accidents–defined by the NTSB as incidents resulting in substantial damage to the aircraft and/or loss of life–far less frequently, with only 11 incursion accidents reported during the same period.
During the 1995-2010 period, USAIG paid more than 900 claims relating to general aviation runway excursions totaling more than $135 million. In the first quarter of 2012 alone, runway excursions accounted for 16 of the 23 safety events involving U.S.-registered business jets, according to data from business aviation safety analyst Robert E. Breiling Associates.
Fear of the Go-Around
Of those 652 excursion accidents tallied by the NTSB, 79 percent occurred during the landing phase, and while the causes for the individual accidents may be varied, the presenters identified the failure of crews to initiate a go-around as one of the leading culprits, implicated in more than one third of the runway excursions.
A recent Flight Safety Foundation study cited in the seminar found that in approximately 35,000 unstable approaches, the crew proceeded to land from 98.6 percent of them. “This is the aviation equivalent of texting while driving,” said Ratté. “We know it’s dangerous, we’ve got policies that say don’t do it, but everybody is doing it anyway.”
That reluctance to abort a landing and go-around is based on many factors. “I think the prime reasons the professional gets drawn out of the professional box are generally pride, pressure, complacency and fatigue,” said Ratté. According to the Flight Safety Foundation’s approach and landing accident reduction (Alar) toolkit, the major rationales include excessive confidence in a quick recovery of the landing, excessive confidence because of [anticipated] runway conditions, inadequate preparation or commitment to go around, absence of decision due to crew fatigue or workload, and the fact that some pilots simply do not identify when they must go around.
Ratté cited a recent survey from the FAA’s landing performance team, which found that half the operators queried lack adequate policies for assessing on the approach whether there is sufficient landing distance. While such calculations were carried out on dispatch, many operators did not include provisions for recalculation of factored landing distance before arrival at the destination, estimations that could be spoiled by changing weather conditions, the presence of tailwinds or by deteriorating runway braking conditions. Such calculations before approach should include an assessment of the environmental state of the runway based on the most current and accurate information available, and properly assessing the correct aircraft performance given those actual runway conditions.
In one case study presented at the seminar, the crew of an airliner overran the end of the runway upon landing. On paper there should have been enough distance to stop (runway length was 7,700 feet and the aircraft’s factored landing distance was 4,300 feet), but the ungrooved runway was wet and the crew overshot the threshold–possibly due to a 14-knot tailwind–touching down approximately halfway down its length, leading to the accident.
In such cases hindsight makes it easy to flag the factors leading to an accident, but in other cases the decisions are less clear. In another example, one of the pilots of a Citation X described how they received an inaccurate assessment about the state of a runway’s contamination from the airport. While on approach, the crew saw the business jet landing before them use most of the runway before it was able to stop, yet they continued with the landing. The crew made repeated requests for information about the runway condition, but it was not until the Citation X was in its landing flare that the pilot of the previous bizjet radioed a report of poor braking action on the runway surface. After the Citation skidded off the side of the runway, the tow truck dispatched to haul it back onto the tarmac struggled to get enough traction on the water-covered icy runway surface.
Christopher Stickney, an aviation human factors consultant and commercial pilot with more than 14,000 hours, said pilots should brief early to understand the risk factors for every landing to be prepared for quick and decisive action should a hazard present itself. He cautioned crews to have a plan of action and to stick with it, and encouraged the adoption of a “just culture” in the cockpit where the pilot monitoring should have the authority to order a go-around if the landing parameters are not being met. A rule adopted as standard operating procedure by the flight department of one audience member was singled out by Ratté. In that company’s landing approach checklist, the final item stated by the pilots before landing is “ready for go-around,” thus mentally arming the pilots for the unexpected.
While some members of the audience mentioned that their aversion to go-arounds possibly stems from having to face questions or file reports with their employers or fellow flight department members, Ratté suggested that any possible follow-up questions would surely be preferable to dealing with an FAA investigator while an aircraft is being hauled out of the mud.
At the end, the take-home message from the presentation could be distilled into one simple tenet: “when in doubt, go around.”