NTSB Factual Report

On July 16, 2006, approximately 1250 mountain daylight time, a Maule M 6 180C single-engine, tailwheel airplane, N72RM, sustained substantial damage following a loss of directional control during takeoff from Kemmerer Municipal Airport (EMM), Kemmerer, Wyoming. The private pilot, who was the sole occupant, was not injured. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The flight was originating at the time of the accident and was destined for Caldwell, Idaho.

According to the pilot, in the fall of 2004, the airplane had been damaged while in a hangar during a hurricane in south Florida. During the repairs, the wings were removed, repaired, and reinstalled. Prior to the pilot's purchase of the airplane, he and an inspection authorization (IA) certificated mechanic examined the airplane and the airplane's maintenance records. In addition to the airplane inspection, the pilot received 2 hours dual instruction in the accident airplane. No anomalies were noted during that flight.

The pilot purchased the airplane in Tennessee and was flying it back to Oregon. During the flight from Tennessee, the pilot noted that the airplane flew "a little left wing low," and no other anomalies were noted. The pilot landed the airplane at EMM to refuel. After refueling, the pilot taxied to runway 34 for takeoff. According to the 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 (24 degrees) for the takeoff. During takeoff roll from EMM, 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 the airplane back to the runway centerline; however, the application of "right rudder was ineffective." The airplane's main landing gear struck a runway light and the airplane was approaching a snow fence. Subsequently, the pilot "intentionally ground-looped the airplane," and the airplane came to rest upright in a field adjacent to the runway.

Examination of the airplane by the pilot and a local mechanic revealed the right main landing gear was collapsed, and the fuselage, right wing, and right elevator were wrinkled.

According to the pilot's logbook, at the time of the accident, he accumulated 223.5 hours in tailwheel airplanes and 21.0 hours in the accident airplane make and model.

On July 21, 2006, representatives of Maule Mod's LLC, Caldwell, Idaho, examined the airplane at the accident site. Examination of the airplane revealed that the wing flap system was not rigged in accordance with the Maule M 6 180C maintenance manual. The accident airplane's "handle full down" flap setting was 0 degrees, however, according to the manual, the "handle full down" flap setting should have been negative 7 degrees. The flap settings were found to be misrigged by 7 degrees through the entire flap setting range.

In accordance with the airplane flight manual, the flap handle position for takeoff should be set the second notch, or 24 degrees of flaps, position. Due to the improper rigged flap setting, the actual flap position during the accident attempted takeoff was 31 degrees. The improper rigged flap system also caused the flap pushrods to contact the wing in the full (forth notch) flap setting.

According to the airplane manufacturer, the 31 degrees of flaps at takeoff would produce increased drag and premature lift of the wing. During takeoff with the improper flap position, elevator authority would be available; however, rudder authority may be decreased at lower airspeeds.

NTSB Probable Cause

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.