Beech V35 accident near Walters, Oklahoma, July 8, 2017
On July 8, 2017 at about 3:50 pm local time, a 1967 Beech V35, registered N6257V, was substantially damaged in an accident during enroute near Walters, Oklahoma (Jones Farm Field Airport). It was a personal flight under general aviation rules (Part 91). 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Maintenance personnel’s installation of an improper vacuum pump gasket, which resulted in oil starvation to the engine and a subsequent 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 8, 2017 · about 3:50 pm local time
- Place
- Walters, Oklahoma · Jones Farm Field Airport · map
- Type
- Accident
- Injuries
- 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech V35 UNDESIGNAT, built 1967 · all V35s on the register
- Registration
- N6257V · no longer on the register · serial D-8587
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airline transport pilot was conducting a personal, cross-country flight. He reported that, about 10 minutes after takeoff, the oil pressure decreased to 0, and the engine experienced a loss of all power. The pilot conducted a forced landing on a soft field about 1 mile short of an airport, during which the airplane sustained substantial damage to the firewall and lower fuselage. A review of the airplane's maintenance records revealed that the vacuum pump had been replaced the day before the accident. Examination of the engine revealed that three connecting rods exhibited thermal and impact damage, and three rod journals were found dry and exhibited thermal discoloration, indicative of oil starvation. Disassembly indicated that a gasket typically used for carburetors was installed on the vacuum pump. The installed gasket did not completely cover the high-pressure oil orifice on the vacuum pump mounting fixture, which resulted in oil leakage, subsequent oil starvation to the engine, and the loss of engine power.
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
- Loss of engine power (total) during enroute defining event
- Off-field or emergency landing during landing
The NTSB's findings
- cause Aircraft › Fluids/misc hardware › Misc hardware › (general) › Incorrect service/maintenance
- cause Personnel issues › Task performance › Maintenance › Installation › Maintenance personnel
- cause Aircraft › Fluids/misc hardware › Fluids › Oil › Fluid level
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; single-engine sea; instrument: airplane
- Flight time: 5,000 hours in all; 26 in this make and model; 20 in the last 90 days
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 3,432 hours
- Last inspection: annual inspection, February 7, 2017; 10 hours since
- Maximum gross weight: 3,400 lb
- Seats: 6
- Landing gear: retractable
- Engine: Continental IO-520-BB6 (piston); 3,441 hours total
The flight
- Departed from: CWC Wichita Falls TX at 3:40 pm
- Destination: LAW Lawton OK
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 130° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 77°F (25°C), dew point 72°F (22°C)
- Altimeter: 30.06 inHg
- Observation at 3:53 pm from LAW, 20 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on January 3, 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 | Memorandum for the Record Pilot Statement CEN17LA286 | PDF, 1 page | View Download |
| 2 | Passenger Statement CEN17LA286 | PDF, 2 pages | View Download |
| 3 | Recent Maintenance Record to Replace Engine Cylinders | PDF, 1 page | View Download |
| 4 | Memorandum for the Record Engine Examination Summary of Findings CEN17LA286- | PDF, 1 page | View Download |
| 5 | Recent Maintenance Record to Replace Vacuum Pump CEN17LA286X | PDF, 1 page | View Download |
| 6 | Memorandum for the Record Vacuum Pump Gasket Examination CEN17LA286 | PDF, 1 page | View Download |
| 7 | Photo Array CEN17LA286 | 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.