ASRS Data Indicates Improper Takeoff Flap Settings Reported 55
Times Since 2000
(A previous version of this story incorrectly attributed the
source of the data used in the USA Today study to the National
Aviation Operations Monitoring Service, or NAOMS. ANN regrets the
error -- Ed.)
The August 20 downing of a Spanair MD-82 on
takeoff has cast the spotlight on a relatively mundane
task for most pilots: setting proper flap positions.
And based on figures cited by USA Today... that may be a good
thing. The national news journal says US pilots reported 55
incidents of improper flap and slat settings on takeoff to NASA's
Aviation Safety Reporting System (ASRS) since 2000.
"This represents a disturbing trend," says Flight Safety
Foundation president Bill Voss. "There are obvious human errors
that are being made that take away ... layers of safety."
According to ASRS responses, most reported cases of
improper takeoff settings were caught by visual and aural cockpit
warning systems, and corrected before the aircraft took off.
Investigators into the Spanair crash -- which killed 154 people --
say those warning systems were inoperative onboard the accident
Proper takeoff settings for flaps (and on larger aircraft,
leading edge slats) are vital for all aircraft, especially for
larger business jets and airliners. Both devices expand the
available lifting surface of an airplane's wing, providing
additional lift during the critical moments when the aircraft must
climb out of ground effect, and establish a safe climb attitude at
relatively slow airspeeds.
The ASRS study lists an 2005 incident at Washington Reagan
National Airport, in which the airliner took off without the
devices deployed. According to the pilots' account of the incident,
the airliner nearly plunged to the ground. Another flight crew
reported to ASRS they erred in failing to set flaps and slats
during their October 2006 takeoff from Orlando.
"Event could have been catastrophic," the pilot said, "had it
not been for (the) takeoff warning horn."
USA Today notes the reported incidents are nearly statistically
irrelevant, compared with over 10 million airline operations per
year... but as pilots know, it also only takes one time for a minor
oversight to become tragic.