Let L-13 accident near Byron, California, August 4, 1991
On August 4, 1991 at about 8:45 pm local time, a Let L-13 (glider), registered N53AS, was substantially damaged in an accident near Byron, California. It was an instructional flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE ON GROUND COLLISION WITH A HIDDEN DITCH NOT VISIBLE TO THE PILOT DURING THE LANDING ROLL OUT PHASE OF A FORCED LANDING.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 4, 1991 · about 8:45 pm local time
- Place
- Byron, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Let L-13 · all L-13s on the register
- Registration
- N53AS · no longer on the register · serial 027057
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT SAID HE WAS RETURNING TO THE GLIDER PORT AFTER A LOCAL SOARING FLIGHT DUE TO A LACK OF LIFT. DURING THE FLIGHT BACK TO THE AIRPORT THE PILOT BECAME AWARE THAT THE RATE OF DESCENT WAS TOO HIGH AND THE GLIDER WOULD NOT MAKE THE AIRPORT RUNWAY. THE PILOT SET UP TO LAND IN A VACANT FIELD COVERED WITH MEDIUM HEIGHT GRASS. THE GLIDER COLLIDED WITH A DITCH DURING THE LANDING ROLL OUT IN THE FIELD. THE DITCH WAS NOT VISIBLE TO THE PILOT UNTIL THE LATTER STAGES OF THE LANDING ROLL OUT.
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: student
- Flight time: 29 hours in all; 23 in this make and model; 5 in the last 90 days; 3 in the last 30 days; 14 as pilot in command
- Medical certificate: None
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded, January 2, 2000
- Maximum gross weight: 1,102 lb
- Seats: 2
- Landing gear: fixed
- Engine: (type not recorded); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 10 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
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.
Other NTSB records under N53AS the same tail number, which may have belonged to a different aircraft at the time
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.