Enstrom F 28F N52PD

Summary

On 22 August 2017 at about 16:04 local time, a Enstrom F 28F registered N52PD, operated by Airwest Aviation Academy LLC, was involved in an incident near Glendale, Arizona, United States. 2 people were on board and nobody was injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

22 August 2017 at 16:04

Classification

Incident

Location

Glendale, Arizona, United States

Nearest airport

Glendale Munical Airport (GEU)

Coordinates

33.5269, -112.2953

Aircraft

Enstrom F 28F

Registration

N52PD

Category

Helicopter

Year built

1996

Engines

1

Operator

Airwest Aviation Academy LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Glendale → Glendale

Aircraft damage

Not recorded

Weather

VMC

Light

Day

NTSB number

WPR17IA198

Nobody was injured.

An internal failure of the turbo-compressor, which resulted in oil leaking into the turbo-compressor’s exhaust.

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

Read the full NTSB narrative

The flight instructor and student pilot were practicing hovering autorotations when the cockpit filled with smoke. The helicopter had just touched down, so the flight instructor secured the cockpit and both he and the student egressed the helicopter with the engine still running. About 5 minutes later, the engine stopped. Postincident examination of the helicopter revealed no fire or other related damage. Maintenance personnel reported that the smoke appeared to have originated from the failure of an internal oil seal within the turbocharger-compressor that leaked oil into the turbocharger-compressor's exhaust system. No further examination or repair was accomplished and the turbocharger was replaced. Further examination revealed damage to the turbocharger-compressor v-clamp assembly that was installed on the exhaust. The strap portion of the v-clamp assembly contained cracks on the outer face that emanated from three of the four spot welds. The edge of the strap portion exhibited evidence of bending deformation on both sides of the assembly. In the deformed areas, the distance between the edge of the retainer and the edge of the strap was smaller when compared to other, non-deformed areas. Further, microscopic examination of the largest crack revealed a fatigue crack emanating from the outer surface of the v-clamp assembly strap. It is likely that the v-clamp assembly bolts were tightened to an extent that caused the deformation in the strap. The damage found to the v-clamp was not related to the source of the smoke.

Quoted verbatim from the NTSB record.