Cessna 208B N9714B

Summary

On 3 July 2017 at about 23:15 local time, a Cessna 208B registered N9714B, operated by Martinaire Aviation LLC, was involved in an accident near Alpine, Texas, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 July 2017 at 23:15

Classification

Accident

Location

Alpine, Texas, United States

Nearest airport

Alpine-Casparis Muni (E38)

Coordinates

30.3931, -103.6703

Aircraft

Cessna 208B

Registration

N9714B

Category

Airplane

Year built

1989

Engines

1

Operator

Martinaire Aviation LLC

Operating rule

Part 135: Air Taxi & Commuter

Phase of flight

Not recorded

Route

Alpine → Eagle Pass

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN17LA254

1 person had minor injuries.

Fracture of a compressor turbine (CT) blade due to operational overtemperatures and the failure of a maintenance technician to detect an existing crack in the CT blade during the last engine inspection.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

While on climbout on a cargo flight, the pilot heard a loud bang, followed by a squealing noise; the engine immediately lost power. The pilot accomplished a forced landing to a field, during which both wings were damaged after contacting power poles. Examination of the engine revealed the compressor turbine (CT) blades had fractured. Material analysis of the CT blades confirmed operational overtemperature conditions had occurred during previous flights, and significant creep in the microstructure of the blades indicated an imminent cracking probability in all the CT blades. During the last borescope inspection about 3 months before the accident, a crack in a CT blade that could be seen in a video recording of the inspection was not observed by the technician who conducted the inspection. It is likely that this CT blade failed due to creep and the undetected crack. The engine's compressor turbine vane ring had features different from an original equipment manufacturer part, including cooling air ducts that were a different size; however, the investigation was not able to determine if cooling air performance was compromised. The CT vane axial positioning, which was staggered, likely increased vibrational loads on the CT blades; however, the investigation was not able to determine if this contributed to the CT blade longevity and crack initiation.

Quoted verbatim from the NTSB record.