Hughes 500D incident near Mcgrath, Alaska, July 5, 2011
On July 5, 2011 at about 3:15 am local time, a Hughes 500D (helicopter), registered N315SH, suffered minor damage in an incident during enroute (descent) near Mcgrath, Alaska (Mcgrath airport). It was flown under charter and air-taxi rules (Part 135). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A fatigue fracture of the governor-to-fuel control Pc line, which resulted in a partial loss of engine power.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 5, 2011 · about 3:15 am local time · cases in 2011
- Place
- Mcgrath, Alaska · Mcgrath · cases near this airport · map
- Type
- Incident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 500D
- Registration
- N315SH · registry record · serial 1120D
- Damage
- Minor damage
- Flight
- Flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that during a descent, the helicopter's engine sound changed abruptly and was immediately followed by the engine-out audio horn, and a red engine-out annunciator light. She entered an emergency autorotation, and then selected a mostly open area that contained some trees as an emergency landing site. During the emergency landing, the main rotor blades struck several small trees as the helicopter touched down on the uneven, tundra-covered terrain. A postincident inspection revealed a fatigue fracture in the engine Pc line that provided compressed air to operate the engine governor and fuel control units. The Pc line met the metallurgical material specifications, but there was a bend in a normally straight portion of the line, which would have placed stress on the Pc line when installed. The additional stress likely resulted in the eventual fatigue failure of the line. It could not be determined how or when the bend occurred.
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 (descent) defining event
- Autorotation Collision with terrain or object (not controlled flight into terrain)
The NTSB's findings
- Environmental issues › Physical environment › Object/animal/substance › Tree(s) › Contributed to outcome
- cause Aircraft › Aircraft power plant › Engine fuel and control › Fuel controlling system › Fatigue/wear/corrosion other cases naming the engine
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 15,382 hours in all; 1,510 in this make and model; 30 in the last 90 days; 15 in the last 30 days; 13,857 as pilot in command; 2,350 on instruments
- Last flight review: March 30, 2011
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 8,601 hours
- Last inspection: 100-hour inspection, June 11, 2011; 91 hours since
- Landing gear: fixed
- Engine: Allison / Rolls Royce 250-C20B (turboshaft); 0 hours total
- Operator: Soloy Helicopters LLC
The flight
- Departed from: PAMC Mcgrath AK at 10:00 pm
- Destination: PAMC Mcgrath AK
Weather at the time
- Light: daylight
- Wind: from 050° at 3 knots
- Visibility: 10 statute miles
- Sky: scat at 11,000 ft
- Temperature: 59°F (15°C), dew point 54°F (12°C)
- Altimeter: 29.70 inHg
- Observation at 10:36 pm from PAFM, 3 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on May 14, 2012. 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 Laboratory 15 - Factual Report 12-004 (7 Embedded Images) | PDF, 4 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 3 | Pilot Statement | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Connections how this case links to the rest of the register
- N315SH on the register today · the tail number may have moved to another aircraft since
- Hughes 386 aircraft on the register
- Engine: Allison / Rolls Royce 250-C20B 113 aircraft carry this series today · as the NTSB recorded it
- MC Grath Airport · nearest airport
- Accidents and incidents in Alaska 5,932 since 1982 · 826 in the last ten years
- Alaska 9,143 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/ANC11IA059.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.