On June 3, 1990, a Cessna 172K (registration N79931) operated by Gower Flying Service was involved in an aviation accident near Tacoma, WA. Investigators recorded the probable cause as: THE PILOT DID NOT ADEQUATELY MAINTAIN A PROPER GLIDE PATH FOR LANDING WHICH RESULTED IN AN INFLIGHT COLLISION WITH A TREE. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 2 related events involving the same aircraft type or operator are linked below.
A VFR flight diverted to an alternate airport due to IFR conditions at destination. During the descent for landing on final approach, the airplane collided with trees. No mechanical failures were found; an altimeter setting discrepancy was noted.
Incident Overview
A visual flight rules (VFR) flight encountered instrument flight rules (IFR) conditions at its intended destination. The pilot decided to divert to another airport that was reporting VFR weather. During the descent for landing on final approach, the airplane collided with trees.
Post-Crash Investigation
Investigators did not find any mechanical failures or malfunctions in the airplane. The cockpit instrument panel was destroyed during the impact sequence. However, the face of the altimeter was recovered.
Altimeter Setting Discrepancy
The barometric pressure window on the retrieved altimeter displayed a setting of 30.10 inches of mercury (in Hg). The last altimeter setting provided by air traffic control to the pilot just prior to the accident was 30.02 in Hg. The difference of 0.08 in Hg corresponds to an altitude error of approximately 80 feet. This would have caused the altimeter to indicate that the airplane was 80 feet higher than its actual altitude above ground level.
Conclusion
The investigation did not state a probable cause for the accident.