Socata TB21 accident near San Marcos, California, July 17, 2022
On July 17, 2022 at about 1:17 am local time, a 2002 Socata TB21, registered N718TB, was substantially damaged in an accident during enroute (cruise) near San Marcos, California. It was a personal flight under general aviation rules (Part 91). 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
The failure of the mechanical fuel pump due to internal friction for reasons that could not be determined based on available evidence, which resulted in a total loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 17, 2022 · about 1:17 am local time
- Place
- San Marcos, California · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Socata TB21, built 2002 · all TB21s on the register
- Registration
- N718TB · no longer on the register · serial 2128
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot, he had just picked up the airplane after an annual inspection. He conducted a pattern-only flight before departing for a cross-country flight to reposition the airplane. About 30 minutes after takeoff, there was a total loss of engine power and the pilot performed a forced landing on a road. The airplane struck a vehicle during landing, which separated the left wing from the fuselage. Postaccident examination of the engine revealed the mechanical fuel pump shaft had sheared. Further disassembly revealed rotational scoring, heat discoloration, and foreign (aluminum) debris on the pump’s rotor shaft and bearing bore. The scoring and heat discoloration were determined to have occurred due to friction occurring between the rotor shaft and bearing bore. Mechanical damage to the affected components did not allow for the determination of pre-event component measurements, including the rotor shaft or the bearing dimensions. The mechanical fuel pump was a recently rebuilt unit and was installed on the engine during the annual inspection that was completed five days before the accident. The overhaul procedures for the fuel pump specify the bearing to be honed and the rotor to be lubricated during reassembly. Honing to incorrect dimensions or improper lubrication would likely result in increased friction between the two components. Debris between the rotor and bearing could also increase friction. The rubber seal installed at the driven end of the rotor exhibited softening and deformation consistent with thermal distress, which could have allowed debris to enter the fuel pump after the pump began to overheat. Additionally, debris could have been introduced during the rebuild process or during the installation process through the fuel line ports and fittings, but due to the friction damage the source of the debris could not be identified. The fuel pump shaft sheared due to the friction between the rotor shaft and bearing bore; however, damage prevented determination of the source of the friction.
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
What happened, in order
- Sys/Comp malf/fail (non-power) during enroute (cruise) defining event
- Fuel starvation during enroute (cruise)
- Collision during takeoff/land during landing
The NTSB's findings
- Aircraft › Aircraft systems › Fuel system › Fuel pumps › Failure
- Personnel issues › Task performance › Maintenance › Repair › Other
- Aircraft › Aircraft power plant › Engine (reciprocating) › (general) › Failure
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Attain/maintain not possible
- Environmental issues › Physical environment › Runway/land/takeoff/taxi surface › (general) › Ability to respond/compensate
- Environmental issues › Physical environment › Object/animal/substance › Ground vehicle › Ability to respond/compensate
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 158 hours in all; 16 in this make and model; 1.2 in the last 90 days; 1.2 in the last 30 days; 63 as pilot in command
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Passenger
- Seat: rgt
The aircraft
- Airframe total time: 634.9 hours
- Last inspection: annual inspection, July 11, 2022
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming TI0-540 SER (piston); 0 hours total
The flight
- Departed from: MYF San Diego CA
- Destination: FUL Fullerton CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 200° at 5 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 800 ft; a few clouds
- Temperature: 68°F (20°C), dew point 63°F (17°C)
- Altimeter: 29.88 inHg
Weather report (METAR): 5:53 PM 68 °F 63 °F 84 % SW 7 mph 0 mph 29.52 in 0.0 in Cloudy
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
10 documents, released by the NTSB on April 25, 2024. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Materials Laboratory Factual Report 23-032 | PDF, 25 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 3 | Pilot Statement | PDF, 2 pages | View Download |
| 4 | Engine Run Report | PDF, 1 page | View Download |
| 5 | Quality Aircraft Accessories (Qaa) Fuel Pump Exam Notes | PDF, 14 pages | View Download |
| 6 | Mor - Fuel Pump Rebuild Procedures | PDF, 2 pages | View Download |
| 7 | Fuel Pump Overhaul Documentation | PDF, 2 pages | View Download |
| 8 | Maintenance Records | PDF, 3 pages | View Download |
| 9 | Statement of Party Representatives to NTSB Investigation | PDF, 2 pages | View Download |
| 10 | Release of Aircraft Wreckage, NTSB Form 6120.15 | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.