Piper PA 31-310 accident near San Diego, California, June 20, 1997
On June 20, 1997 at about 7:31 pm local time, a Piper PA 31-310, registered N266MM, was destroyed in an accident near San Diego, California (Brown Field). It was an other work-use flight under general aviation rules (Part 91). 3 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The loss of power in the left engine for undetermined reasons and the pilot's subsequent failure to maintain minimum single-engine control airspeed. A contributing factor was the pilot's decision to fly with known deficiencies in the equipment.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 20, 1997 · about 7:31 pm local time
- Place
- San Diego, California · Brown Field · map
- Type
- Accident
- Injuries
- 3 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA 31-310 · all PA 31-310s on the register
- Registration
- N266MM · no longer on the register · serial 31-140
- Damage
- Destroyed
- Flight
- Other work-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The aircraft concluded an aerial survey and landed at Brown Field to clear U.S. Customs. On restart, as the left engine began running, a witness noticed two short, yellow flame bursts exit the exhaust. During taxi, the witness heard a popping sound coming from the aircraft. As power was applied to cross runway 26L, the sound went away. The aircraft stopped for a few seconds prior to pulling onto the runway; the witness did not observe or hear a run-up. Witnesses reported hearing a series of popping sounds similar to automatic gunfire and observed the aircraft between 600 and 1,000 feet above the ground with wings level and the landing gear up. The aircraft was observed to make an abrupt, 45-degree banked, left turn as the nose dipped down. Witnesses reported the nose of the aircraft then raised up toward the horizon. This was followed by the aircraft turning to the left and becoming inverted in an estimated 30-degree nose low attitude. With the nose still low, the aircraft continued around to an upright position and appeared to be in a shallow right bank. Witnesses then lost sight of the aircraft due to buildings and terrain. A May 20, 1997, work order indicated the left manifold pressure fluctuated in flight. Both wastegates were lubricated and a test flight revealed the left engine manifold pressure lagged behind the right engine manifold pressure. On June 18, 1997, the left engine differential pressure controller was noted to have been removed and replaced. This was the corrective action for a discrepancy write up that the left engine manifold pressure fluctuated up and down 2 inHg and the rpm varied by 100 in cruise. A test flight that afternoon by the accident pilot indicated the discrepancy still occurred at cruise power settings, but the engine operated normally at high and low power settings. Postaccident functional checks were performed on various components. No discrepancies were noted for the left governor. The left engine differential pressure controller was damaged and results varied on each test. The left density controller was too damaged to test. The right engine density and differential pressure controllers tested satisfactory. The left and right fuel pumps operated within specifications. Both fuel servos were damaged. One injection nozzle on the left engine was partially plugged; all others flow tested within specifications.
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, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 10,041 hours in all; 1,586 in this make and model; 73 in the last 90 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 8,473 hours
- Last inspection: annual inspection, September 27, 1996; 80 hours since
- Maximum gross weight: 6,500 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming TIO-540 (piston); 0 hours total
The flight
- Departed from: SDM at 7:30 pm
- Destination: MYF CA
- Flight plan: none
- Runway 26R, 7,999 ft by 200 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 250° at 11 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 73°F (23°C), dew point 59°F (15°C)
- Altimeter: 29.00 inHg
- Observation at 7:30 pm from SDM, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 3 |
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.