ASN Wikibase Occurrence # 29993
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: | Monday 16 October 2000 |
| Time: | 23:55 |
| Type: |  Aérospatiale AS 350F2 Ecureuil |
| Owner/operator: | Corporate Jets, Inc. |
| Registration: | N355DU |
| MSN: | 5489 |
| Year of manufacture: | 1992 |
| Total airframe hrs: | 4192 hours |
| Engine model: | Rolls-Royce 250-C20F |
| Fatalities: | Fatalities: 1 / Occupants: 1 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | East of 2613 Churchill Drive, Burlington, NC -
 United States of America
|
| Phase: | Initial climb |
| Nature: | Ferry/positioning |
| Departure airport: | 4NC3 |
| Durham, NC (NC92) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
About 5 minutes before landing at a hospital, the main rotor gearbox (MGB) oil pressure warning light illuminated. The pilot continued to the hospital, landed, and performed an immediate engine shutdown. A mechanic disconnected the wiring to the MGB oil pressure switch and the light went out. The mechanic stated he believed the oil pressure switch had failed and he asked the pilot to run the helicopter, hover the helicopter, and if everything was normal, to fly it back to the base hospital. The pilot did the run and hover, and then departed the hospital. The helicopter crashed about 1 minute later. Witnesses stated they heard the helicopter approach the crash site at a low altitude and making a slow thumping noise. Examination of the MGB showed the oil pump idler gear had seized in the oil pump due to undetermined reasons and the oil pump drive shaft had failed due to overstress. The teeth on the engine input gears, intermediate gears, and MGB drive gear in the MGB combining gearbox had failed due to high-temperature overstress, which was the result of oil starvation. The helicopter was not equipped with a MGB oil pressure indicator. The maintenance procedure for trouble shooting an illuminated MGB oil pressure warning light is to first check the electrical circuit, and if this does not correct the problem, to change the oil pressure switch. The mechanic stated he did not have the maintenance manuals with him while working on the helicopter. The MGB had been installed in the helicopter after overhaul, 3 days and 4 flight hours before the accident.
Probable Cause: The mechanics failure to comply with manufacturers instructions for correction of a illuminated main rotor gearbox oil pressure warning light resulting in the helicopter being dispatched on a ferry flight with a failed main rotor gearbox oil pump, failure of the main rotor gearbox combining gearbox gears due to oil starvation, loss of main rotor RPM, and the helicopter colliding with trees and the ground during an uncontrolled descent.
Sources:
NTSB: https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20001212X22206&key=1
FAA register: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?omni=Home-N-Number&nNumberTxt=355DU
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 27-Sep-2008 01:00 | ASN archive | Added |
| 07-Mar-2009 11:30 | harro | Updated |
| 09-Jul-2014 23:04 | Dr. John Smith | Updated [Time, Location, Source, Narrative] |
| 30-Nov-2016 21:05 | Aerossurance | Updated [Aircraft type, Location, Source, Narrative] |
| 21-Dec-2016 19:16 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 21-Dec-2016 19:20 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 12-Dec-2017 19:14 | ASN Update Bot | Updated [Operator, Departure airport, Destination airport, Source, Narrative] |
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