Casualties unknown

Airplane Collides with Mountain During Cruise Flight (N4650G)

Lebanon, NH, US

On May 17, 1991, a Cessna 172N (registration N4650G) operated by Classic Air Charter Corp. was involved in an aviation accident near Lebanon, NH. Investigators recorded the probable cause as: THE PILOT'S FAILURE TO MAINTAIN ADEQUATE TERRAIN CLEARANCE. CONTRIBUTING WAS MOUNTAINOUS TERRAIN, LOW CLOUDS, AND VFR FLIGHT INTO IMC. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 1 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards

An airplane collided with a 4700-foot mountain about 200 feet below its summit approximately 18 miles from departure. Radar data showed altitude variations. Another pilot reported clouds obscuring the mountain. No mechanical malfunction was found. The pilot had recently resumed flying after 17 years of inactivity.

Accident Overview

An airplane collided with a mountain at an elevation of approximately 4700 feet, about 200 feet below its summit, during cruise flight. The accident site was located roughly 18 miles from the departure point.

Flight Path and Radar Data

Recorded radar data indicated the airplane's altitude varied between 4000 and 5400 feet MSL over a 10-minute period. The last radar return was recorded at 0816 EDT, 16 minutes after departure. The flight path roughly corresponded to a direct northerly course between the departure point and destination.

Weather and Visibility

Another pilot, who flew near the accident site approximately one hour after the accident airplane departed, reported that the mountain was obscured by clouds at that time.

Aircraft Examination

An examination of the airplane did not disclose evidence of mechanical malfunction.

Pilot Background

The pilot had been inactive from flying for about 17 years and resumed flying approximately two months before the accident. During that period, the pilot also acquired 3 hours of instrument flight training.

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Frequently asked questions

What happened in the 17 May 1991 Cessna 172N accident near Lebanon, NH?

An airplane collided with a 4700-foot mountain about 200 feet below its summit approximately 18 miles from departure. Radar data showed altitude variations. Another pilot reported clouds obscuring the mountain. No mechanical malfunction was found. The pilot had recently resumed flying after 17 years of inactivity.

What aircraft was involved and where did it happen?

The accident on 17 May 1991 involved a Cessna 172N, registration N4650G, operated by Classic Air Charter Corp., at Lebanon, NH.

What was the probable cause of the accident?

THE PILOT'S FAILURE TO MAINTAIN ADEQUATE TERRAIN CLEARANCE. CONTRIBUTING WAS MOUNTAINOUS TERRAIN, LOW CLOUDS, AND VFR FLIGHT INTO IMC.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X16927. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.