Beech J35 accident near San Jose, California, August 14, 1991
On August 14, 1991 at about 1:15 am local time, a Beech J35, registered N3028C, was substantially damaged in an accident near San Jose, 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 FAILURE OF THE CRANKSHAFT COUNTERWEIGHT RETAINING CLIP DUE TO IMPROPER MAINTENANCE INSTALLATION OF THE PART.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 14, 1991 · about 1:15 am local time
- Place
- San Jose, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech J35 · all J35s on the register
- Registration
- N3028C · no longer on the register · serial D-5693
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE ENGINE WAS OVERHAULED AND MODIFIED ABOUT SIX OPERATING HOURS PRIOR TO THE ACCIDENT WITH A NEW TYPE OF CAM SHAFT UNDER THE PROVISIONS OF A SUPPLEMENTAL TYPE CERTIFICATE. THE PILOT SAID HE WAS IN LEVEL CRUISE WHEN HE HEARD A LOUD BANG EMANATE FROM THE ENGINE CONCURRENTLY WITH IT STOPPING. AN INITIAL INSPECTION OF THE AIRCRAFT ON SITE BY FAA INSPECTORS REVEALED THAT OIL COVERED THE WIND SHIELD. THE NUMBER TWO CYLINDER ROD WAS OBSERVED TO BE PROTRUDING FROM A HOLE IN THE TOP OF THE ENGINE CASE. ONE COUNTER WEIGHT ASSEMBLY WAS FOUND MISSING FROM THE CRANKSHAFT COUNTERWEIGHT BLADE. THE MISSING COUNTERWEIGHT, COVER PLATES, RETAINING CIR-CLIPS, AND ASSOCIATED BUSHINGS WERE FOUND IN THE OIL PAN. OPTICAL EXAMINATION OF THE RECOVERED PIECES REVEALED THAT THE RETAINING CIR-CLIP FAILED, ALLOWING THE COUNTER WEIGHT PIN AND THE WEIGHT ITSELF TO SEPARATE FROM THE CRANKSHAFT. THE INSPECTOR DETERMINED THAT THE CIR-CLIP HAD BEEN INSTALLED BACKWARDS.
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; instrument: airplane
- Flight time: 676 hours in all; 71 in this make and model; 30 in the last 90 days; 8 in the last 30 days; 572 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,685 hours
- Last inspection: annual inspection, February 13, 1991; 26 hours since
- Maximum gross weight: 2,900 lb
- Seats: 4
- Landing gear: retractable
- Engine: Continental IO-470-C (piston); 0 hours total
- Operator: Dtb Aviation
The flight
- Destination: 307 Hollister CA
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 300° at 12 knots
- Visibility: 25 statute miles
- Sky: scat at 10,000 ft
- Temperature: 90°F (32°C), dew point 68°F (20°C)
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.