Hiller UH 12D accident near Mehama, Oregon, July 17, 2020
On July 17, 2020 at about 3:54 pm local time, a 1960 Hiller UH 12D (helicopter), registered N2297W, was destroyed in an accident during maneuvering near Mehama, Oregon. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
An in-flight separation of a tail rotor blade due to fatigue cracking and overstress, which resulted in a loss of directional control and subsequent ground impact.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 17, 2020 · about 3:54 pm local time
- Place
- Mehama, Oregon · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH 12D No Series, built 1960 · all UH 12Ds on the register
- Registration
- N2297W · no longer on the register · serial 1206
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The pilot was performing an aerial application flight. No radar information was available for the flight. The support truck operator reported that the helicopter departed from the truck and flew toward a field. Shortly after the helicopter departed, the truck operator heard the pilot report over the radio that he was “going down.” A witness reported that the engine noise changed pitch and became loud before impact. A postcrash fire ensued. The helicopter struck several large trees and came to rest inverted at the base of a large tree. Postaccident examination of the engine revealed no anomalies that would have precluded normal operations. However, the tail rotor assembly was found fractured and separated from the tailboom with parts scattered in the initial part of the debris field. One tail rotor blade remained secured at the hub, and the other blade was fractured and separated. The tension-torsion straps for that blade extended outward from the hub and were fractured and splayed. Metallurgical examination revealed that 10 of the 11 straps fractured from fatigue cracking followed by overstress. The fatigue cracking initiated at multiple locations along the bores in contact with the cylindrical plain bearing. Wear, in the form of smearing, gouging, spalling, and galling of the faying surfaces, led to the fatigue crack initiation. The fatigue cracks then propagated perpendicular to the area with the highest tensile stresses and at the thinnest locations along the bearing bore. No indications of corrosion were observed. Thus, the tail rotor blade separated during flight due to fatigue cracking and overstress. According to the component replacement schedule, the tension-torsion strap bundles are to be replaced every 12,500 flight hours and were set to be removed in 1,383.3 flight hours from the time of the accident.
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 control in flight during maneuvering (low-alt flying)
- Part(s) separation from AC during maneuvering defining event
The NTSB's findings
- Aircraft › Aircraft structures › (general) › (general) › Fatigue/wear/corrosion
- Aircraft › Aircraft propeller/rotor › Tail rotor › Tail rotor blade › Fatigue/wear/corrosion
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 11,884 hours in all; 10,334 in this make and model; 11,753 as pilot in command
- Last flight review: April 12, 2020
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 4,243 hours
- Last inspection: 100-hour inspection, July 14, 2020; 16 hours since
- Maximum gross weight: 2,750 lb
- Seats: 3
- Landing gear: fixed
- Engine: Rolls Royce 250-C20B (turboshaft); 4,233 hours total
- Fire on the ground
- Operator: Western Helicopter Service Inc
The flight
- Departed from: OR38 Brooks OR at 12:30 pm
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 320° at 4 knots
- Visibility: 10 statute miles
- Sky: overcast at 3,800 ft; scat at 2,000 ft
- Temperature: 66°F (19°C), dew point 55°F (13°C)
- Altimeter: 30.09 inHg
- Observation at 3:56 pm from SLE, 18 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
13 documents, released by the NTSB on August 30, 2022. 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.
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N2297W the same tail number, which may have belonged to a different aircraft at the time
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.