Amateur-built EDGE 540 accident near Livermore, California, February 19, 1999
On February 19, 1999, a amateur-built EDGE 540, registered N9ND, was substantially damaged in an accident near Livermore, California. It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 19, 1999
- Place
- Livermore, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built EDGE 540
- Registration
- N9ND · no longer on the register · serial 0020
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane; rotorcraft: glider
- Flight time: 3,500 hours in all; 200 in this make and model; 33 in the last 90 days; 17 in the last 30 days; 3,250 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 200 hours
- Last inspection: annual inspection, February 18, 1999; 1 hours since
- Maximum gross weight: 1,800 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming AEIO-540-EXP (piston); 0 hours total
The flight
- Departed from: TCY Tracy CA at 11:20 pm
- Destination: SQL San Carlos CA
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 240° at 9 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 1,500 ft; clear
- Temperature: 50°F (10°C), dew point 46°F (8°C)
- Altimeter: 30.00 inHg
- Observation at 11:53 pm from LVK, 6 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.