Accident Overview
A single-engine airplane, operated on a company visual flight rules flight plan, was involved in an accident while returning from a three-day pipeline patrol mission. The aircraft was crewed by an instrument-rated commercial pilot and an observer. On the morning of the accident, the crew had resumed following a pipeline as part of a 693-nautical mile cross-country flight to their home base. Standard procedure for such patrols involved flying approximately 500 feet above the pipeline while the observer inspected it.
Sequence of Events
As the aircraft approached an airport for a planned fuel stop, it struck trees near the top of a hill. The point of impact was approximately 1.45 miles northeast of the approach end of the runway and near its extended centerline. After the initial tree contact, the airplane continued for about 275 feet before coming to rest in an inverted position.
Wreckage and Conditions
The wreckage was not discovered until approximately 1230 the following day. The airplane was equipped with an emergency locator transmitter (ELT), which was found in the "OFF" position. All major components of the aircraft were accounted for at the accident site, and there was no evidence of fire. An examination of the airframe and engine revealed no pre-impact anomalies that would have prevented normal operation.
Weather and Visibility
At the time of the accident, the airport's automated weather observation facility reported a visibility of 5 statute miles and a 300-foot overcast ceiling. The accident occurred during daylight hours.
Investigation Findings
The investigation did not identify any mechanical or structural failures that could have contributed to the accident. The ELT's off position was noted, but no analysis was provided regarding its impact on the timeline of wreckage location.