Pilot Debrief

CESSNA 421C near Longmont, CO — 2021-07-10

Final reportCEN21LA315
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Date
2021-07-10
Location
Longmont, CO, USA
Airport
LMO
Aircraft
CESSNA 421C
Registration
N66NC
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Takeoff roll

Probable cause

The loss of performance for reasons that could not be determined.

NTSB narrative

The pilot reported that he performed the “before starting engine” and “starting engine” checklists and everything was normal before taking off in the twin-engine airplane. He performed an engine runup and then started his takeoff roll. The pilot reported that about halfway down the runway the airplane was not accelerating as fast as it should. He attempted to rotate the airplane; however, “the airplane mushed off the runway.” The airplane settled back onto the runway, then exited the departure end of the runway, where it sustained substantial damage to the wings and fuselage. The airplane engine monitor data indicated the airplane’s engines were operating consistent with each other at takeoff power at the time of the accident. Density altitude at the time of the accident was 7,170 ft and according to performance charts, there was adequate runway for takeoff. The reason for the loss of performance could not be determined.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted takeoff earlier when sensing inadequate acceleration.

NTSB coding

Evidence available

  • FDR / data
  • Photos
  • 9 docket documents
View NTSB final reportView NTSB docket

Docket documents9

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