Sc Aerostar SA YAK 52W accident near El Cajon, California, September 23, 2017
On September 23, 2017 at about 9:15 pm local time, a 1991 Sc Aerostar SA YAK 52W, an amateur-built aircraft,, registered N52KF, was substantially damaged in an accident during taxi near El Cajon, California (Gillespie Field). 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 pilot's failure to maintain directional control during taxi after a reduction in braking performance and steering capabilities due to his failure to reopen the air supply valve after the nonstandard engine start.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 23, 2017 · about 9:15 pm local time
- Place
- El Cajon, California · Gillespie Field · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Sc Aerostar SA YAK 52W NO SERIES, built 1991, amateur-built · all YAK 52Ws on the register
- Registration
- N52KF · registry record · serial 9111213
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
After completing an uneventful preflight inspection, the pilot was unable to start the engine due to low pressure in the pneumatic system. An individual arrived with a tank of air to pressurize the system while the pilot remained in the airplane. The pilot shut off the compressed air supply valve, as required during a pneumatic system recharge; however, the recharge could not be accomplished due to an incorrect adapter. While the individual left to find the correct adapter, another individual offered to help start the engine manually by turning the propeller. After the engine started, the pilot forgot to reopen the compressed air supply valve and, during taxi, the airplane experienced a loss of braking performance that affected its steering capabilities (the steering is accomplished through differential braking, and the brake system requires pneumatic pressure to operate). The pilot was unable to maintain directional control, and the airplane subsequently collided with a fence and sustained substantial damage to the left wing. The checklist for the make/model airplane does not require the pilot to check the air pressure or valve position during the preflight, engine start, or before takeoff phases.
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
- Aircraft servicing event during prior to flight
- Loss of control on ground during taxi defining event
- Ground collision during taxi
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Forgotten action/omission › Pilot
- cause Aircraft › Aircraft systems › Pneumatic system › Pneumatic distribution system › Not used/operated
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Attain/maintain not possible
- Environmental issues › Physical environment › Object/animal/substance › Fence/fence post › Contributed to outcome
Pilot
- Certificate: airline transport pilot, flight instructor, flight engineer
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane; rotorcraft: glider
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: unk
- Injury: no injuries
Passenger
- Seat: unk
The aircraft
- Maximum gross weight: 2,899 lb
- Landing gear: fixed
- Engine: Ama/Expr UNKNOWN ENG; 0 hours total
The flight
- Departed from: SEE El Cajon CA at 9:15 pm
- Destination: SEE El Cajon CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 230° at 8 knots
- Visibility: 10 statute miles
- Sky: scat at 5,000 ft
- Temperature: 72°F (22°C), dew point 52°F (11°C)
- Altimeter: 29.84 inHg
- Observation at 9:47 pm from KSEE
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on June 25, 2020. 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 | Pilot's Statement | PDF, 2 pages | View Download |
| 2 | Yak Manual Excerpt | PDF, 4 pages | View Download |
| 3 | Photos | PDF, 4 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.