Sikorsky S-64E accident near Index, Washington, June 27, 1991
On June 27, 1991 at about 9:05 pm local time, a Sikorsky S-64E (helicopter), registered N6959R, was destroyed in an accident near Index, Washington. It was an other work-use flight under external-load helicopter rules (Part 133). 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE CONTROL INTERFERENCE BY THE MECHANIC WHEN HE INADVERTENTLY RAISED THE COLLECTIVE PITCH AND THE COPILOT'S FAILURE TO ATTEND THE FLIGHT CONTROLS. FACTORS RELATING TO THE ACCIDENT WERE THE MOTION SICKNESS OF THE MECHANIC, INADEQUATE COLLECTIVE PITCH CONTROL LOCKING MECHANISM UTILIZED BY THE COMPANY, AND ADMINISTRATIVE TASKS THAT DIVERTED THE CO-PILOT'S ATTENTION FROM ATTENDING THE FLIGHT CONTROLS.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 27, 1991 · about 9:05 pm local time · cases in 1991
- Place
- Index, Washington · map
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Sikorsky S-64E · all S-64Es on the register
- Registration
- N6959R · no longer on the register · serial 64002
- Damage
- Destroyed
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
THE ACFT WAS ON AN EXTERNAL LOAD LOGGING OPN AND THE PIC HAD LANDED AT A FIELD SITE TO REFUEL. THE PIC EXITED, WITH THE ACFT RUNNING AT FULL RPM WHILE IT WAS BEING REFUELED, AND THE COPILOT REMAINED IN THE RIGHT SEAT COMPLETING LOAD REPORTS. THE ACFT CONTROLS WERE UNATTENDED. THE CREW CHIEF WAS SEATED IN THE AFT FACING HOIST OPR STATION, WHICH HAD THE COLLECTIVE PITCH STICK INSTALLED BESIDE THE SEAT. HE HAD BECOME AIR SICK DURING THE FLT, AND REMAINED SEATED AFTER THE PIC EXITED. WHEN HE ATTEMPTED TO EXIT, WHICH REQUIRED THAT HE STAND, TURN AROUND AND STEP UP OUT OF THE SEAT WELL, THE ACFT TOOK OFF TO A HOVER AND ROTATED TO THE LEFT. THE TAIL ROTOR STRUCK A ROTOR BLADE BOX ON TOP OF A SUPPORT TRAILER PARKED BY THE REFUELING SITE, FRACTURING THE AFT TAIL BOOM, PYLON AND TAIL ROTOR FROM THE ACFT. THE ACFT PITCHED NOSE DOWN, ROLLED OVER AND IMPACTED THE GROUND.
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: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 17,000 hours in all; 9,000 in this make and model; 110 in the last 90 days; 48 in the last 30 days; 15,000 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 42,000 lb
- Seats: 3
- Landing gear: fixed
- Engine: P&W JFTD12A4A (turboshaft); 0 hours total
- Fire on the ground
- Operator: Erickson Air Crane CO.
The flight
- Departed from: NONE Index WA at 8:15 pm
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 340° at 13 knots
- Visibility: 35 statute miles
- Sky: scat at 2,500 ft
- Temperature: 70°F (21°C), dew point 52°F (11°C)
- Altimeter: 29.00 inHg
- Observation at 8:52 pm from PAE, 38 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.
Connections how this case links to the rest of the register
- N6959R: not on the register today · the record of its deregistration
- Sikorsky S-64 16 registered today · the model family and its accident history
- Sikorsky 827 aircraft on the register
- Engine: P&W JFTD12A4A 12 aircraft carry this series today · as the NTSB recorded it
- Accidents and incidents in Washington 2,713 since 1982 · 362 in the last ten years
- Washington 10,644 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/SEA91FA143.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.