Robinson R-22B N4015Y

Summary

On 11 April 1995 at about 17:48 local time, a Robinson R-22B registered N4015Y, operated by Resort Aviation, was involved in an accident near Lakeport, California, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

11 April 1995 at 17:48

Classification

Accident

Location

Lakeport, California, United States

Nearest airport

Lampson Field (102)

Coordinates

39.0403, -122.9295

Aircraft

Robinson R-22B

Registration

N4015Y

Category

Helicopter

Engines

1

Operator

Resort Aviation

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX95LA158

Nobody was injured.

the student's misjudged landing flare and his failure to verify the validity of the low rotor warning. Factors in the accident were the company management's continued use of the helicopter in flight training operations with a known discrepancy in the main rotor warning system, and the soft nature of the soil at the autorotation landing area.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

THE STUDENT WAS DOING TAKEOFFS AND LANDINGS IN THE TRAFFIC PATTERN WHEN THE LOW ROTOR RPM WARNING HORN ACTIVATED. THE STUDENT WAS UNSUCCESSFUL IN EXTINGUISHING THE WARNING HORN BY THROTTLE AND COLLECTIVE MANIPULATION AND ENTERED AN AUTOROTATION. THE STUDENT DID NOT VERIFY THE MAIN ROTOR RPM BY THE ROTOR TACHOMETER. DURING THE TOUCHDOWN, ABOUT 1/4-MILE SOUTHEAST OF THE AIRPORT IN A SOFT FIELD, THE SKIDS DUG INTO SOFT SOIL AND THE HELICOPTER ROLLED OVER. A FAA INSPECTOR EXAMINED THE AIRCRAFT AND ENGINE, WHICH INCLUDED AN ENGINE START AND STATIC RUN-UP. THE ENGINE STARTED NORMALLY AND WAS EXERCISED THROUGHOUT ITS NORMAL POWER RANGE. MAINTENANCE RECORDS REVEALED A HISTORY OF FALSE LOW ROTOR RPM WARNING HORN ACTIVATIONS IN THE HELICOPTER DATING BACK 9 MONTHS. AFTER PILOTS WOULD REPORT THE WARNING HORN DISCREPANCY TO MAINTENANCE PERSONNEL, A SYSTEM COMPONENT WOULD BE CHANGED AND THE HELICOPTER RETURNED TO SERVICE; HOWEVER, THE PROBLEM PERSISTED. THE CFI'S SAID THEY TRAINED THE STUDENTS, INCLUDING THE ACCIDENT PILOT, HOW TO COPE WITH THE NUISANCE WARNING.

Quoted verbatim from the NTSB record.