Enstrom F 28F incident near Glendale, Arizona, August 22, 2017
On August 22, 2017 at about 4:04 pm local time, a 1996 Enstrom F 28F (helicopter), registered N52PD, was involved in an incident near Glendale, Arizona (Glendale Munical Airport). It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
An internal failure of the turbo-compressor, which resulted in oil leaking into the turbo-compressor’s exhaust.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 22, 2017 · about 4:04 pm local time
- Place
- Glendale, Arizona · Glendale Munical Airport · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Enstrom F 28F, built 1996 · all F 28Fs on the register
- Registration
- N52PD · registry record · serial 807
- Damage
- Not recorded
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
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
- Autorotation Fire/smoke (non-impact) defining event
- Fire/smoke (non-impact) during landing
- Engine shutdown during after landing
The NTSB's findings
- cause Aircraft › Aircraft power plant › Turbocharging (recip only) › Turbocharger › Malfunction
- Aircraft › Aircraft power plant › Turbocharging (recip only) › (general) › Fatigue/wear/corrosion
Flight instructor
- Certificate: flight instructor, commercial pilot, private
- Ratings: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,300 hours in all; 1,280 in this make and model; 90 in the last 90 days; 1,220 as pilot in command; 960 on instruments
- Last flight review: December 18, 2015
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
Dual student
- Certificate: private, student
- Ratings: single-engine land
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 6,264.3 hours
- Last inspection: annual inspection, July 6, 2017
- Maximum gross weight: 2,600 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycomng HIO-360-F1AD (piston); 965 hours total
- Operator: Airwest Aviation Academy LLC
The flight
- Departed from: GEU Glendale AZ at 3:20 pm
- Destination: GEU Glendale AZ
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 020° at 4 knots
- Visibility: 10 statute miles
- Sky: scat at 15,000 ft
- Temperature: 91°F (33°C), dew point 57°F (14°C)
- Altimeter: 29.97 inHg
- Observation at 3:53 pm from KGEU
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on August 27, 2018. 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 | Materials Lab Factual Report No. 17-074 | PDF, 7 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 3 | Record of Email | PDF, 2 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.