ASN Wikibase Occurrence # 353127
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Friday 25 June 1999 |
| Time: | 15:43 LT |
| Type: |  RotorWay Exec 162F |
| Owner/operator: | Private |
| Registration: | N112WM |
| MSN: | 6369 |
| Total airframe hrs: | 4 hours |
| Engine model: | Rotorway RI-162 |
| Fatalities: | Fatalities: 0 / Occupants: 1 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Pacoima, CA -
 United States of America
|
| Phase: | Initial climb |
| Nature: | Unknown |
| Departure airport: | Whiteman, CA (KWHP) |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The experimental helicopter experienced a loss of engine power in the takeoff initial climb, about 450 feet agl, and the pilot autorotated to a hard landing on a city street. A witness who saw the helicopter hovering before takeoff said that the engine 'missed' twice before the helicopter took off. After the helicopter took off and was about 80 to 90 feet agl, he heard the engine make a 'sputtering' or 'popping' noise. This flight was the first test flight after building the helicopter and the pilot had completed 4.3 hours of engine run-ups and hover time. Examination of the engine found that the No. 3 cylinder intake valve stem cap was damaged and the rocker arm was loose. The valve lash clearances on the other three cylinders were found to be from 0.006 to 0.022 inches greater than the manufacturer's specifications. No other damage was noted to the engine or valve train. The No. 3 cylinder intake valve stem cap was replaced and the other valve clearances set to the proper 0.004-inch specification. The engine was then installed in a test cell and performed normally during all operational tests. The RotorWay Engine Manual instructs owners to measure and adjust the valve lash, and states, 'if any adjustment is necessary at one hour, valve adjustment should be repeated hourly until the lash stabilizes.' The pilot reported that he had made a total of four adjustments during the first inspection, but after that, all measurements had been within the manufacturer's specifications.
Probable Cause: The pilot's improper valve adjustments and failure to follow the manufacturer's instructions, which resulted in a loose number 3 cylinder rocker arm and a loss of engine power.
Accident investigation:
 |
|
Sources:
NTSB LAX99LA236
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 09-Mar-2024 10:36 | ASN Update Bot | Added |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation