Piper PA-32RT-300T accident near San Mateo, California, September 25, 1994
On September 25, 1994 at about 8:50 pm local time, a Piper PA-32RT-300T, registered N39658, was destroyed in an accident near San Mateo, California (San Carlos airport). It was a personal flight under general aviation rules (Part 91). 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A deteriorated magneto grounding ('P' lead) and failure of maintenance personnel to detect this condition when the engine was reinstalled in the airframe after overhaul. The lack of suitable terrain for the forced landing was a factor.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 25, 1994 · about 8:50 pm local time
- Place
- San Mateo, California · San Carlos · map
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-32RT-300T PA-32RT-30 · all PA-32RT-300Ts on the register
- Registration
- N39658 · no longer on the register · serial 32R-7887135
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE AIRCRAFT LOST ENGINE POWER AFTER TAKEOFF AND WAS FORCED TO LAND ON A RESIDENTIAL STREET. THE ENGINE HAD BEEN OVERHAULED BY AN FAA-CERTIFIED REPAIR STATION 5 MONTHS AND 150 FLIGHT HOURS BEFORE THE ACCIDENT. EXAMINATION OF THE ENGINE MAGNETO REVEALED INTERNAL CORROSION AND ELECTRICAL ARCING AT THE BREAKER POINTS. THE INSULATION ON THE 'P' LEAD WIRE WAS CRACKED ALONG ITS ENTIRE LENGTH EXPOSING BARE WIRE AT ONE POINT. GROUNDING OF THE 'P' LEAD AS A RESULT OF A BARE WIRE TOUCHING THE AIRFRAME WOULD HAVE THE SAME EFFECT AS THE IGNITION SWITCH IN THE OFF POSITION.
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: private
- Ratings: single-engine land
- Flight time: 340 hours in all; 45 in this make and model; 45 in the last 90 days; 35 in the last 30 days; 330 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,429 hours
- Last inspection: 100-hour inspection, August 29, 1994; 15 hours since
- Maximum gross weight: 3,600 lb
- Seats: 6
- Landing gear: retractable
- Engine: Lycoming TIO-540-S1AD (piston); 0 hours total
- Operator: Aero Haven, INC.
The flight
- Departed from: SQL San Carlos CA at 8:45 pm
- Destination: L35 Big Bear City CA
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 020° at 8 knots
- Visibility: 8 statute miles
- Temperature: 70°F (21°C), dew point 61°F (16°C)
- Altimeter: 29.00 inHg
- Observation at 8:47 pm from SQL, 4 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.