Pilot Debrief

ROBINSON HELICOPTER COMPANY R22 near Truckee, CA — 2017-11-30

Final reportWPR18LA041
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Date
2017-11-30
Location
Truckee, CA, USA
Airport
TRK
Aircraft
ROBINSON HELICOPTER COMPANY R22
Registration
N47WH
Category
Helicopter
Highest injury
Serious
Fatalities
0
Phase of flight
Maneuvering

Probable cause

The flight instructor’s failure to execute a power recovery from a non-stabilized autorotative descent, which resulted in a hard landing.

NTSB narrative

The flight instructor was demonstrating an autorotation with a 180° left turn at a density altitude of about 6,470 ft. He entered the maneuver from 700 ft above ground level (agl) and about 80 kts indicated airspeed, established engine rpm, and started the 180° turn. About 1/3 of the way through the turn, he felt he needed a “desirable” speed through the turn and moved the cyclic forward and adjusted the collectively accordingly. The flight instructor stated that when he should have been 2/3 through the turn, he felt that he did not have the cyclic and collective control of the helicopter and he knew they were going to crash. He further stated that he continued “teaching,” and called out “rpm, airspeed, and outside,” while pointing to the tachometer, airspeed indicator, and intended landing spot; he also made control inputs and continued to fly what “had become an unresponsive aircraft.” He also stated that there was no flare at the end of the autorotation and no time for an engine rpm recovery. Postaccident examination of the airframe and engine revealed no mechanical anomalies that would have precluded normal operation. The helicopter manufacturer’s Safety Notice SN-38 stated that if any of the parameters for rotor rpm, a stabilized airspeed, a stabilized rate of descent or turns (if any) completed are not correct, an immediate power recovery should be initiated; salvaging the situation by coaching the student or trying to correct below 100 ft agl (200 ft when operating at or above 4000 ft density altitude) should not be attempted. Had the flight instructor aborted the autorotation early on, it is likely he would have regained helicopter control.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Instructor should have aborted the maneuver when helicopter showed signs of unresponsiveness.

NTSB coding

Evidence available

  • Photos
  • 12 docket documents
View NTSB final reportView NTSB docket

Docket documents12

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