May 30, 2014
Two fatal business aircraft runway excursions in the past two years highlight the potential consequences of runway excursions. A September 2013 accident involving a Cessna Citation in Santa Monica, CA resulted in four fatalities, and a January 2014 accident involving a Challenger 600 in Aspen, CO resulted in one fatality and two serious injuries. Yet runway incursion prevention often receives more time in pilot training than does runway excursion prevention.
“Runway excursions are low-frequency, high-consequence failures, so they don’t receive as much attention as they should,” said Rich Boll, a member of the NBAA Access Committee.
A runway excursion is defined as “a veer off or overrun off the runway surface.” From 2001 to 2010, runway excursions during the landing phase made up 80 percent of runway excursion accidents. However runway excursions during the takeoff phase are more likely to result in serious injuries or fatalities.
NBAA encourages business aircraft operators to develop policies and procedures to mitigate the risk of runway excursions.
“Operators need to understand the performance data in the Airplane Flight Manual (AFM) and the certification criteria behind that data. In most cases, landing distance data in the AFM was originally intended to be applied by dispatch rules in Parts 121 and 135. As such, it is not required to consider variables like runway slope, higher temperatures and higher-pressure altitudes as corrections to the landing distance data. Higher temperatures and higher-pressure altitudes result in higher true airspeeds and, therefore, longer landing distances. These factors are often not considered in AFM landing distance data,” said Boll.
Boll cautions that some AFMs do consider these variables, but the performance data numbers are still based on a maximum performance stop, which is not an event most business aircraft passengers would appreciate. The published data also assumes pilots touch down at the appropriate point – generally 1,000 feet from the approach end of the runway. Boll also warns that extended flares and attempts for smooth landings have a pronounced effect on how long it will take the airplane to stop.
Boll suggests business aircraft operators consider implementing landing distance policies similar to those required in Part 91(K) fractional operations or eligible on-demand operations, which allow the operator to plan to use 80 percent of the runway length, leaving a 20 percent safety buffer. If the operator is flying an aircraft that supplies only the minimum data required by Part 25, Boll suggests considering an additional landing factor similar to standard Part 135 requirements, which requires a planned 40 percent landing buffer.
“Awareness is key,” said Boll. “It’s not always short runways that create the highest risk of runway excursions – short runways tend to heighten the pilot’s awareness of the threat. The riskiest runways are those the pilot feels comfortable with.”
On Tuesday, June 24, from 1 to 2 p.m. (EDT), NBAA will host a webinar titled, “Runway Excursions: The Business Aviation Perspective,” focusing on risk factors that contribute to runway excursions. The webinar, which will feature Alan Gorthy of the FAA’s Runway Safety Group, will help operators gain a better understanding of how performance parameters affect pilots’ ability to avoid runway excursions, as well as other incidents and accidents. Even those unable to attend the webinar may register to gain access to a recording of the session, along with all materials.
The webinar is free to NBAA Members.
“Al Gorthy is a formal naval aviator and current FAA air safety inspector with the Central Region’s Runway Safety Office,.” said Boll. “He has conducted extensive research into the problem of runway excursions and incursions. His research not only deals with the root causes of runway incursions and excursions, but also deals with the certification rules, operating rules and operational aspects of the problems as well.”