Casualties unknown

1996-09-28: Piper PA-30 (N37P) — Watkins, CO

Watkins, CO, US

On September 28, 1996, a Piper PA-30 (registration N37P) was involved in an aviation accident near Watkins, CO. Investigators recorded the probable cause as: Insufficient engine power due to the manual turbochargers not being engaged during takeoff, as required by the operating instructions for high-density-altitude conditions. 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 1781061362Data APIEditorial standards

An aircraft on a cross-country flight failed to climb or accelerate after takeoff. The manual turbochargers were not engaged, resulting in inadequate manifold pressure for the high-density-altitude conditions.

Takeoff Incident

During a cross-country flight, the aircraft became airborne after takeoff but was unable to climb or accelerate. The aircraft's weight was 3,670 pounds, approximately 100 pounds below the maximum allowable takeoff weight. The density altitude at the time was 6,000 feet msl.

Turbocharger Configuration

The aircraft was equipped with manual turbochargers, which were not used during the takeoff. According to the aircraft's operating instructions, the turbochargers should be utilized for high-altitude takeoffs to achieve the desired manifold pressure of 29.5 inches of mercury at 2,700 rpm.

Power Output

Without the turbochargers engaged, the engines produced only 23.5 inches of manifold pressure. This power level was insufficient for a climb at the prevailing aircraft weight and speed. The required manifold pressure for the takeoff conditions was 29.5 inches, which could only be achieved by engaging the turbochargers.

Summary

The aircraft's inability to climb and accelerate was directly related to the lack of turbocharger use during takeoff in high-density-altitude conditions, resulting in inadequate engine power.

Probable cause

Insufficient engine power due to the manual turbochargers not being engaged during takeoff, as required by the operating instructions for high-density-altitude conditions.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001208X06743. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.