NTSB Factual Report

HISTORY OF FLIGHT

On May 27, 2001, at 1705 central daylight time, a Cessna 150H, N23033, piloted by a private pilot, was destroyed while maneuvering near Protem, Missouri. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions and was not on a flight plan. The pilot received serious injuries. The one passenger was fatally injured. The local flight originated from the Boone Country Airport (HRO), Harrison, Arkansas about 1630.

In a written statement, the pilot said that he and his passenger departed HRO at 1630 and flew to the Protem, Missouri area. He said that they were flying near his house at 800 feet above ground level so that the passenger could photograph the residence. The pilot said that he reduced airspeed and lowered 10-15 degrees of flaps, keeping the airspeed at the upper end of the flap operating range. The pilot stated that he executed a turn to the left. The pilot stated that when he began the left turn, he heard a, "loud pop in the left wing." He said that the control yoke was, "jerked out of [his] hand to the full left stop." The pilot said that the airplane continued to roll to the left even with full right aileron input. He stated that he lowered the flaps in an effort to, "slow [the airplane] down a little and therefore lessen the impact. However, all this did was intensify the roll." The airplane subsequently impacted trees and terrain.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with a single engine land rating. He had accumulated a total of 182.4 hours total flight experience with 160.0 of those flight hours in the same make and model as the accident airplane. He held a third class medical certificate issued on June 29, 2000. No limitations or waivers were listed on the medical certificate.

AIRCRAFT INFORMATION

The airplane was a 1968 Cessna 150H, serial number 15068691. A 100 horsepower Continental O-200-A engine, serial number 199282-9-A, powered the airplane. The airplane had accumulated a total of 3797 hours at the time of the accident. A sticker was found in the rental time record book that listed the following: "Annual 3/01"; "100 Hr 3850"; "AD's due 3850"; "ELT due 8/01"; "Pitot static 2/01"; "Oil change due 3800". A review of the aircraft logbooks, which were not in the airplane, indicated the most recent annual inspection was performed on March 15, 2000.

WRECKAGE AND IMPACT INFORMATION

The Federal Aviation Administration (FAA) conducted a postaccident examination of the airplane. The wreckage was contained to an area about 50 feet by 50 feet. The seats, seat stops, and seat belts remained attached and intact. There were no shoulder harnesses installed in the airplane. No anomalies were found with respect to the engine or fuel system that could be determined to have existed prior to the impact. No anomalies were found with respect to the aileron, rudder, or elevator control systems that could be determined to have existed prior to the impact. The flap actuator jackscrew was extended 5.95 inches. The flap position indicator was indicating full down. The flap control system was examined and a break in the flap control cable was observed. The broken flap cable and the right hand inboard pulley and bracket assembly were retained for further examination.

TESTS AND RESEARCH

The broken flap cable, flap pulley, and pulley bracket were examined at the National Transportation Safety Board's Materials Laboratory in Washington, D.C. The cable break contained signatures consistent with overstress failure. The pulley bracket had a crescent wear mark adjacent to but outside of the cotter pin intended to retain the cable in the pulley groove. The wear mark was covered with a black residue and its appearance was not fresh. No wear was observed on the cotter pin. The complete report of the laboratory examination is appended to this report.

ADDITIONAL INFORMATION

The FAA, Cessna Aircraft, and Teledyne Continental Motors, were parties to the investigation.

NTSB Probable Cause

The overload of the flap control cable for undetermined reasons resulting in aircraft control not being possible. The trees were a factor.