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ASN Wikibase Occurrence # 201987
Last updated: 25 January 2022
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Date:18-FEB-1999
Time:16:40
Type:Silhouette image of generic EDGE model; specific model in this crash may look slightly different
Zivko Edge 540
Owner/operator:Norman Dewit Air Shows, Llc
Registration: N9ND
MSN: 0020
Fatalities:Fatalities: 0 / Occupants: 1
Other fatalities:0
Aircraft damage: Substantial
Category:Accident
Location:Livermore, CA -   United States of America
Phase: Unknown
Nature:Private
Departure airport:Tracy, CA (TCY)
Destination airport:San Carlos, CA (SQL)
Investigating agency: NTSB
Narrative:
The pilot said he was in normal cruise flight when the 200-hour since new Lycoming AEIO-540 engine began to over speed. The pilot said a roughness, which progressively worsened, was associated with the onset of the over speed event. He stated that he was unsuccessful in regaining control of the engine and initiated a power-off forced landing to a clear area next to a highway. The aircraft touched down in soft, muddy soil and the landing gear was torn out of the structure. Cracks were found across the rear of the engine case between the Nos. 5 and 6 cylinders. Disassembly of the engine revealed that one of the two counterweight rollers had become dislodged from the corresponding counterweight crankshaft lug bore and precipitated a catastrophic internal failure of the No. 6 connecting rod. Detailed examination of the separated counterweight crankshaft lug bore revealed rotational scoring around the inside diameter of the hole, while the roller bushing was broken in two pieces and displayed rotational scoring marks around the outside diameter. The designed bushing to bore clearance provides for an interference fit. The problematic lug bore was measured for circularity, position, and diameter with respect to design specifications. The lug bore was found outside of acceptable tolerances in all areas. According to Textron Lycoming and the FAA, a small number of crankshafts by serial number where produced with the lug bore(s) misreamed to an out of round condition during that stage of the manufacturing process. The accident crankshaft by serial number was outside of the believed problem range.
Probable Cause: The manufacturer's inadequate quality control procedures, which allowed an improperly manufactured crankshaft to be shipped, resulting in the separation of one counterweight from the crankshaft lug and the subsequent catastrophic internal failure of the engine.

Sources:

NTSB: https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20001205X00191&key=1

Other occurrences involving this aircraft

1 May 2016 N9ND Private 0 Budapest non


Revision history:

Date/timeContributorUpdates
26-Nov-2017 10:01 ASN Update Bot Added

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