Casualties unknown

2006-07-16: Maule M 6 180C (N72RM) — Kemmerer, WY

Kemmerer, WY, US

On July 16, 2006, a Maule M 6 180C (registration N72RM) was involved in an aviation accident near Kemmerer, WY. Investigators recorded the probable cause as: the pilot's loss of directional control during takeoff due to the improper rigging of the airplane's flap system by unknown maintenance personnel. A contributing factor was the high density altitude. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During a cross-country flight, a pilot experienced a loss of directional control on takeoff after the airplane's flaps were found to be misrigged by 7 degrees, with the actual flap setting 7 degrees greater than selected.

Accident Overview

In the fall of 2004, the accident airplane was damaged while in a hangar during a hurricane. Repairs included removal and reinstallation of the wings. Prior to the pilot's purchase, he and an inspection authorization (IA) certificated mechanic examined the airplane and its maintenance records. During a cross-country flight to the pilot's state of residence, an intermediate fuel stop was made.

Pre-Takeoff Conditions

After refueling, the pilot taxied to runway 34 for takeoff. According to the airport's automated weather observing system (AWOS), the density altitude was 10,300 feet mean sea level and the wind was 4 knots from the west. In accordance with the airplane flight manual, the pilot selected the second notch of flaps, corresponding to 24 degrees, for takeoff.

Takeoff and Loss of Control

During the takeoff roll, the airplane began to "lift off (feel light) and the tail wheel left the ground, the [airplane] began turning left." The pilot attempted to maneuver back to the runway centerline, but application of "right rudder was ineffective." The main landing gear struck a runway light and the airplane was approaching a snow fence. Subsequently, the pilot "intentionally ground-looped the airplane," and it came to rest upright in a field adjacent to the runway.

Post-Accident Examination

Examination of the airplane revealed that the wing flap system was not rigged in accordance with the maintenance manual. The "handle full down" flap setting measured 0 degrees, whereas the manual specified negative 7 degrees. Flap settings were misrigged by 7 degrees throughout the entire range. Due to this, the actual flap position during the attempted takeoff was 31 degrees instead of the intended 24 degrees. According to the airplane manufacturer, 31 degrees of flaps at takeoff would produce increased drag and premature lift of the wing. Elevator authority would be available, but rudder authority may be decreased at lower airspeeds.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20060718X00963. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.