Casualties unknown

Pilot fails to clear trees after aborted seaplane takeoff in dense air (N64BC)

Moultonboro, NH, US

On July 25, 1982, a Piper PA-18S (registration N64BC) operated by Robert M. Carson was involved in an aviation accident near Moultonboro, NH. Investigators recorded the probable cause as: The pilot's inability to clear trees due to insufficient climb performance in heavy air during an aborted takeoff. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

A pilot attempted an aborted takeoff from a seaplane due to heavy air density but was unable to clear nearby trees during the climb-out phase.

What happened

The pilot initiated a taxi to a takeoff point located farther out than usual. The aircraft struggled to transition onto the step due to very dense atmospheric conditions, with the temperature estimated at 78 degrees. Upon reaching the abort point, the pilot applied back pressure to lift the seaplane off the water. However, the aircraft failed to gain sufficient altitude and struck trees during the climb-out.

The investigation

The investigation focused on the performance of the seaplane under high-density altitude conditions. The primary finding was that the heavy air prevented the aircraft from achieving the necessary lift-to-drag ratio for a safe climb gradient after aborting the takeoff.

Findings

  • High density altitude significantly degraded aircraft performance during the critical takeoff phase.
  • The pilot's decision to taxi to an extended takeoff point did not compensate for the lack of air density.
  • Inability to clear obstacles was the direct result of insufficient climb performance after the aborted takeoff.

Safety message

Pilots must carefully calculate takeoff performance based on actual temperature and pressure conditions. Aborted takeoffs from seaplanes require careful consideration of remaining water length and potential obstacle clearance requirements, especially in high-density altitude environments.

Probable cause

The pilot's inability to clear trees due to insufficient climb performance in heavy air during an aborted takeoff.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20020917X03973. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.