On January 21, 1995, a Piper PA-31-350 (registration N36PB) was involved in an aviation accident near LA Grande, OR. Investigators recorded the probable cause as: FAILURE OF THE PILOT TO MAINTAIN PROPER ALTITUDE/CLEARANCE FROM HIGHER TERRAIN THAT WAS LOCATED NEAR THE AIRPORT. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
While flying an NDB approach in IMC, a pilot noted a weak signal and wandering ADF needle. Continuing the approach, he felt the airplane hit a tree, performed a missed approach, and diverted to another airport. Investigation revealed the NDB was out of service with no NOTAM issued.
Incident Overview
A pilot reported that while flying an NDB approach in instrument meteorological conditions (IMC), he noticed the identifying signal was weak and the ADF needle wandered. Despite these anomalies, he continued the approach but did not descend below the minimum descent altitude (MDA) of 4000 feet MSL. When he believed he was over the runway, he looked down and saw trees through the fog. Immediately thereafter, he felt the airplane strike something. He executed a missed approach and diverted to another airport, where he landed without further incident.
Examination and Investigation
An examination of the airplane revealed evidence that it had collided with a tree. An investigation disclosed that the NDB was out of service, and no NOTAM had been issued. The party responsible for reporting the serviceability of the NDB had informed the Flight Service Station (FSS) that the "beacon" was out of service. The FSS interpreted "beacon" as the rotating beacon on the airport. The airport was situated in a valley at an elevation of 2714 feet. The NDB approach to the airport was conducted from the north, with high terrain reaching about 6000 feet MSL located to the east and west. The investigation did not determine the precise location of the tree impact.