Cessna 208B accident near Verdigris, Oklahoma, March 24, 2015
On March 24, 2015 at about 8:07 pm local time, a 1988 Cessna 208B, registered N106BZ, was substantially damaged in an accident during enroute (climb to cruise) near Verdigris, Oklahoma. It was a flight test under general aviation rules (Part 91). 1 person had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The fuel pump gear manufacturer’s allowance of set-up gears made from a nonconforming material to be put in the production inventory system, the installation of a nonconforming gear in the accident airplane’s production fuel pump, and the gear’s failure, which resulted in a loss of fuel flow to the engine and the subsequent 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
- March 24, 2015 · about 8:07 pm local time
- Place
- Verdigris, Oklahoma · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 208B, built 1988 · all 208Bs on the register
- Registration
- N106BZ · no longer on the register · serial 208B0106
- Damage
- Substantial damage
- Flight
- Flight test · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, during the postmaintenance test flight, the turboprop engine lost power. The airplane was unable to maintain altitude, and the pilot conducted a forced landing, during which the airplane was substantially damaged. The engine had about 9 total flight hours at the time of the accident. A teardown of the fuel pump revealed that the high-pressure drive gear teeth exhibited wear and that material was missing from them, whereas the driven gear exhibited little to no visible wear. A metallurgical examination of the gears revealed that the damaged drive gear was made of a material similar to 300-series stainless steel instead of the harder specified M50 steel, whereas the driven gear was made of a material similar to the specified M50 steel. Subsequent to these findings, the airplane manufacturer determined that the gear manufacturer allowed three set-up gears made from 300-series stainless steel to become part of the production inventory during the manufacturing process. One of those gears was installed in the fuel pump on the accident airplane, and the location of the two other gears could not be determined. Based on the evidence, it is likely that the nonconforming gear installed in the fuel pump failed because it was manufactured from a softer material than specified, which resulted in a loss of fuel flow to the engine and the subsequent loss of engine power. The manufacturer subsequently inspected its stock of gears and issued notices to customers that had engines with fuel pumps installed with the same part number gear set as the one installed on the accident airplane. The manufacturer also issued a service information letter and service bulletins regarding the fuel pump gear set for engines used in civilian and military applications. As of the date of this report, the two remaining gears have not been located.
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 (partial) during enroute (climb to cruise) defining event
- Collision with terrain or object (not controlled flight into terrain) during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine fuel and control › Fuel pump › Fatigue/wear/corrosion
- cause Organizational issues › Support/oversight/monitoring › Oversight › Parts/tools tracking › Manufacturer
- cause Aircraft › Fluids/misc hardware › Fluids › Fuel › Not specified
Pilot
- Certificate: airline transport pilot, foreign licence
- Ratings: single-engine land; instrument: airplane
- Flight time: 6,500 hours in all; 970 in this make and model; 22 in the last 90 days; 10 in the last 30 days; 5,500 as pilot in command
- Last flight review: February 8, 2015
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 11,443 hours
- Last inspection: annual inspection, March 11, 2015; 9 hours since
- Maximum gross weight: 7,449 lb
- Seats: 2
- Landing gear: retractable
- Engine: Honeywell TPE331-12JR (turboprop); 9 hours total
The flight
- Departed from: TUL Tulsa OK at 8:00 pm
- Destination: TUL Tulsa OK
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 220° at 11 knots, gusting 21
- Visibility: 10 statute miles
- Sky: broken clouds at 6,000 ft
- Temperature: 82°F (28°C), dew point 55°F (13°C)
- Altimeter: 29.73 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 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.
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.