Hughes 369D accident near Vallejo, California, March 31, 1989
On March 31, 1989 at about 1:25 am local time, a Hughes 369D (helicopter), registered N5108E, was substantially damaged in an accident near Vallejo, California. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FATIGUE FAILURE OF A DEFECTIVE PC TUBE ASSEMBLY RESULTING IN A LOSS OF ENGINE POWER. A CONTRIBUTING FACTOR WAS THE UNSUITABLE TERRAIN.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 31, 1989 · about 1:25 am local time
- Place
- Vallejo, California · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 369D · all 369Ds on the register
- Registration
- N5108E · registry record · serial 811075D
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
DURING AN AIR TAXI CARGO FLIGHT ENGINE POWER WAS SUDDENLY LOST & THE PILOT AUTOROTATED TO A LANDING ON A WET MARSH. AS THE AIRCRAFT CAME TO REST THE MAIN ROTORS SEVERED THE TAIL BOOM. EXAM OF THE ENGINE REVEALED THAT THE PC TUBE ASSEMBLY, P/N 6848471, HAD FAILED AT THE SCROLL FITTING FERRULE, & THIS BROKEN LINE CONDITION PRODUCED AN IMMEDIATE LOSS OF ENGINE POWER. THE PC TUBE HAD A TOTAL OF 11.8 HOURS OF USE SINCE BEING INSTALLED/MANUFACTURED. A METALLURGICAL FAILURE ANALYSIS REVEALED THAT THE PC TUBE HAD FAILED IN FATIGUE.
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: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 5,017 hours in all; 284 in this make and model; 187 in the last 90 days; 84 in the last 30 days; 4,933 as pilot in command; 1,294 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,697 hours
- Last inspection: 100-hour inspection, March 20, 1989; 12 hours since
- Maximum gross weight: 3,000 lb
- Seats: 2
- Landing gear: fixed
- Engine: Allison C250-C20B (turboshaft); 0 hours total
- Operator: Helinet, INC.
The flight
- Departed from: 056 Novato CA at 1:15 am
- Destination: CCR Concord CA
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 30 statute miles
- Sky: clear
- Temperature: 70°F (21°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.