Tulsa - Tulsa

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.

Flight / Schedule

Tulsa - Tulsa

Registration

N106BZ

MSN

208B-0106

Year of Manufacture

1988

Date

March 24, 2015 at 03:07 PM

Type

CRASH

Flight Type

Test

Flight Phase

Flight

Crash Site

Plain, Valley

Crash Location

Verdigris Oklahoma

Region

North America • United States of America

Coordinates

36.2348°, -95.6911°

Crash Cause

Technical failure

Narrative Report

On March 24, 2015 at 03:07 PM, Tulsa - Tulsa experienced a crash involving Cessna 208B Grand Caravan, operated by Private American, with the event recorded near Verdigris Oklahoma.

The flight was categorized as test and the reported phase was flight at a plain, valley crash site.

2 people were known to be on board, 0 fatalities were recorded, 2 survivors were identified or estimated. This corresponds to an estimated fatality rate of 0.0%.

Crew on board: 1, crew fatalities: 0, passengers on board: 1, passenger fatalities: 0, other fatalities: 0.

The listed crash cause is technical failure. 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.

Aircraft reference details include registration N106BZ, MSN 208B-0106, year of manufacture 1988.

Geospatial coordinates for this crash are approximately 36.2348°, -95.6911°.

Fatalities

Total

0

Crew

0

Passengers

0

Other

0

Crash Summary

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.

Cause: Technical failure

Occupants & Outcome

Crew On Board

1

Passengers On Board

1

Estimated Survivors

2

Fatality Rate

0.0%

Known people on board: 2

Operational Details

Schedule / Flight

Tulsa - Tulsa

Flight Type

Test

Flight Phase

Flight

Crash Site

Plain, Valley

Region / Country

North America • United States of America

Aircraft Details

Registration

N106BZ

MSN

208B-0106

Year of Manufacture

1988