Piper PA-31-350 accident near Ontario, California, September 15, 1989
On September 15, 1989 at about 1:52 pm local time, a Piper PA-31-350, registered N70PE, was destroyed in an accident near Ontario, California (Ontario Int'L airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FAILURE OF THE RIGHT PROPELLER HUB DUE TO METAL FATIGUE WHICH RESULTED IN CATASTROPHIC SEPARATION OF THE PROPELLER. CONTRIBUTING TO THE ACCIDENT WAS DAMAGE DONE TO THE AIRCRAFT AIRFRAME IN FLIGHT BY THE SEPARATING PROPELLER MAKING THE AIRCRAFT UNCONTROLLABLE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 15, 1989 · about 1:52 pm local time
- Place
- Ontario, California · Ontario Int'L · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-31-350 · all PA-31-350s on the register
- Registration
- N70PE · registry record · serial 31-805 2137
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
THE PROPELLER SEPARATED FROM THE RIGHT ENGINE DURING THE INITIAL CLIMB. EXAMINATION OF THE WRECKAGE REVEALED THE PROPELLER HUB FRACTURE RESULTED IN ONE OF THE THREE PROPELLER BLADES DETACHING FROM THE HUB. THE REST OF THE PROPELLER HUB THEN SEPARATED STRIKING THE RIGHT FRONT OF THE FUSELAGE. OIL WAS SPREAD ACROSS THE AIRCRAFT NOSE AND WINDSHEILD. THE FUSELAGE RIGHT SIDE DAMAGE INCREASED AERODYNAMIC DRAG. WITNESSES REPORTED THE ENGINE COWLING WAS TORN. THE AIRCRAFT ENTERED A RIGHT TURN AND DIVE. IT IMPACTED THE GROUND IN A NEAR INVERTED ATTITUDE. METALLURGICAL EXAMINATION OF THE FAILED PROP HUB REVEALED METAL FATIGUE EMANATING FROM THE THREADED HOLE FOR THE GREASE FITTING. THE THREADS HAD BEEN DEFORMED BY SHOT PEENING, RESULTING IN INCREASED STRESS CONCENTRATIONS AT THE THREADS.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 1,916 hours in all; 89 in the last 90 days; 49 in the last 30 days
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,118 hours
- Last inspection: approved inspection programme, August 22, 1989; 39 hours since
- Maximum gross weight: 7,000 lb
- Seats: 8
- Landing gear: retractable
- Engine: Lycoming TIO-540-J2BD (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: ONT Ontario CA at 1:50 pm
- Destination: SBA Santa Barbara CA
- Flight plan: VFR
- Runway 0R
Weather at the time
- Light: daylight
- Visibility: 7 statute miles
- Sky: scat at 200 ft
- Temperature: 70°F (21°C), dew point 45°F (7°C)
- Altimeter: 29.00 inHg
- Observation at 1:50 pm from ONT, 2 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.