Hughes 500D accident near Ketchikan, Alaska, June 12, 1995
On June 12, 1995 at about 1:15 pm local time, a Hughes 500D (helicopter), registered N549SW, was substantially damaged in an accident near Ketchikan, Alaska. It was an other work-use flight under general aviation rules (Part 91). 4 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
AN AIR LEAK AT A 'B' NUT FITTING ON A PNEUMATIC PC TUBE TO THE POWER TURBINE GOVERNOR. COMPANY MAINTENANCE PERSONNEL DID NOT DETECT A LEAK AFTER PERFORMING MAINTENANCE ON THE GOVERNER AND P2 AIR LINE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 12, 1995 · about 1:15 pm local time
- Place
- Ketchikan, Alaska · map
- Type
- Accident
- Injuries
- 4 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 500D
- Registration
- N549SW · no longer on the register · serial 800754D
- Damage
- Substantial damage
- Flight
- Other work-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE HELICOPTER PILOT WAS IN CRUISE FLIGHT ABOUT 250 FEET ABOVE THE GROUND, TRANSPORTING LOGGING PERSONNEL TO A REMOTE AREA. THE ENGINE SUDDENLY LOST POWER, AND THE PILOT BEGAN AN AUTOROTATION TO A GRAVEL PIT. DURING TOUCHDOWN, THE TAILBOOM WAS SEVERED, AND THE HELICOPTER ROLLED ONTO ITS RIGHT SIDE. DURING RECOVERY OF THE HELICOPTER, THE LIFTING CABLE BROKE, AND THE HELICOPTER DESCENDED TO THE GROUND FROM ABOUT 400 FEET. POSTACCIDENT EXAMINATION OF THE ENGINE FUEL CONTROL AND POWER TURBINE GOVERNOR DID NOT REVEAL ANY MALFUNCTION. EXAMINATION OF THE PNEUMATIC PC TUBE (AIR LINE) FROM THE PC FILTER TO THE GOVERNOR REVEALED AN AIR LEAK AT THE 'B' NUT ATTACHMENT TO THE GOVERNOR 'T' FITTING. LABORATORY TESTING REVEALED THAT A TORQUE OF 300 INCH POUNDS WOULD HAVE BEEN REQUIRED TO STOP THE AIR LEAK. THE MANUFACTURER'S SPECIFIED TORQUE VALUE WAS 100 INCH POUNDS. RECORDS SHOWED THAT ON 6/7/95, MAINTENANCE HAD BEEN PERFORMED TO REPLACE THE GOVERNOR AND TO CLEAN AND REINSTALL THE P2 AIR LINE; AND ON 6/11/95 (DAY BEFORE THE ACCIDENT), THE ENGINE SPEED HAD BEEN ADJUSTED. THE MAINTENANCE MANUAL FOR THE ENGINE WARNED THAT AIR LEAKS IN THE PNEUMATIC SENSING SYSTEM COULD RESULT IN FLAME-OUT, POWER LOSS, OR OVERSPEED.
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
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane; rotorcraft: helicopter
- Flight time: 15,000 hours in all
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 4,278 hours
- Last inspection: continuous airworthiness programme, May 18, 1995; 76 hours since
- Maximum gross weight: 3,000 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: Fire Cove AK at 7:30 am
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: scat at 6,000 ft
- Temperature: 52°F (11°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 3 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.