Amateur-built Series 5 accident near Yucca Grove, California, April 5, 2024
On April 5, 2024 at about 3:00 am local time, a 1998 amateur-built Series 5, registered N743JT, was substantially damaged in an accident during enroute (cruise) near Yucca Grove, California. It was a personal 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 pilot’s improper repair of the oil sump, which resulted in a loss of oil pressure and collision with terrain during a precautionary landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 5, 2024 · about 3:00 am local time
- Place
- Yucca Grove, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built Series 5, built 1998
- Registration
- N743JT · registry record · serial S9501-0091
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported the engine run-up and takeoff were normal. While in cruise flight the pilot noticed a slight drop in oil pressure. With no increase in oil temperature or other engine warnings he decided to continue the flight while monitoring the engine parameters. A short time later the oil pressure began to drop at a faster rate. He decided to perform a precautionary landing. He shut down the engine and configured the airplane for landing on a highway service road, but while on approach he noticed the landing area was obstructed by light poles. He maneuvered the airplane towards an adjacent dirt field; however, the terrain was much rougher than anticipated, and the airplane nosed over during roll out after striking scrub brush. The engine’s oil sump had a crack in its mounting flange that resulted in a loss of oil on previous flights, but not at a significant rate. The crack was then improperly repaired by the pilot, who used epoxy putty to seal it rather than having it welded or replaced. During the accident flight, which was the first since the repair, the crack propagated beyond the putty fill area and the putty unbonded, resulting in most of the engine oil being expelled out of the crack.
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
- Powerplant sys/comp malf/fail during enroute (cruise) defining event
- Nose over/nose down during landing (landing roll)
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng oil sys › Fatigue/wear/corrosion
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng oil sys › Incorrect service/maintenance
- Personnel issues › Task performance › Maintenance › Repair › Pilot
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: glider; instructor: instrument airplane; instrument: airplane; rotorcraft: glider
- Flight time: 5,370 hours in all; 69 in this make and model; 90 in the last 90 days; 49 in the last 30 days; 3,050 as pilot in command
- Last flight review: March 16, 2024
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 838.4 hours
- Last inspection: condition inspection, September 11, 2023; 13.7 hours since
- Maximum gross weight: 1,550 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental C90-12F (piston); 87 hours total
The flight
- Departed from: CCB Upland CA at 1:34 am
- Destination: HND Las Vegas NV
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 230° at 16 knots, gusting 30
- Visibility: 10 statute miles
- Sky: a few clouds at 12,000 ft
- Temperature: 68°F (20°C), dew point 28°F (-2°C)
- Altimeter: 29.57 inHg
- Observation at 6:56 pm from KLAS, 46 miles away
Weather report (METAR): METAR KLAS 050156Z 23016G30KT 10SM VCBLDU FEW120 FEW250 20/M02 A2957 RMK AO2 PK WND 18036/0124 SLP000 T02001022=
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Photographs from the investigation 1 picture from the NTSB's docket, as the NTSB released them
The NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.
Documents from the investigation the NTSB's docket: the evidence folder behind the report
6 documents, released by the NTSB on November 26, 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 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 2 | Accident Site Photo | PDF, 2 pages · our copy | View Download |
| 3 | NTSB Engine Examination Report | PDF, 6 pages | View Download |
| 4 | Video Attachment to the NTSB Engine Examination Report | MOV file | Download |
| 5 | Jpi Engine Monitor Data | data file | Download |
| 6 | Engine Logbook Excerpts | 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.
Other NTSB records under N743JT 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.