Hiller UH-12E accident near Marshall, Washington, November 10, 1998
On November 10, 1998 at about 5:00 pm local time, a Hiller UH-12E (helicopter), registered N752GB, was destroyed in an accident near Marshall, Washington. It was an other work-use flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The loss of the bolt that connects the lateral cyclic linkage push rod to the lower end of the upper firewall-mounted lateral cyclic linkage bellcrank, resulting in an uncontrolled descent into the terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 10, 1998 · about 5:00 pm local time
- Place
- Marshall, Washington · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH-12E · all UH-12Es on the register
- Registration
- N752GB · no longer on the register · serial 1752
- Damage
- Destroyed
- Flight
- Other work-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While climbing out after takeoff from the helicopter pad located at the pilot's residence/place of business, the bolt that connected the lower end of the upper-firewall lateral cyclic linkage bellcrank to its push rod separated from the aircraft. With the bolt missing from the control linkage, the necessary increase of the angle of attack (cyclic feathering) of the retreating blade (port blade) could not take place. Without this feathering, which is produced by the lateral position of the cyclic, the forward-moving blade (starboard side)produced considerably more lift than the retreating blade. This resulted in an uncontrolled roll to the left and an uncontrolled descent into the terrain.
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: single-engine land; single-engine sea; instructor: airplane single-engine; instructor: helicopter; instrument: airplane; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 9,300 hours in all; 7,000 in this make and model
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 8,515 hours
- Last inspection: 100-hour inspection, June 17, 1998; 91 hours since
- Maximum gross weight: 3,100 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-540-C2A (piston); 0 hours total
The flight
- Destination: Keller WA
- Flight plan: none
- Runway 0
Weather at the time
- Light: not reported
- Wind: from 170° at 7 knots
- Visibility: 10 statute miles
- Sky: scat at 4,000 ft
- Temperature: 36°F (2°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
- Observation at 4:56 pm from KGE, 12 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
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.