Hiller UH-12E accident near Miltonfreewater, Oregon, May 21, 1997
On May 21, 1997 at about 5:51 pm local time, a Hiller UH-12E (helicopter), registered N3005J, was substantially damaged in an accident near Miltonfreewater, 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
The main rotor blade separated due to fatigue. Factors were: an Airworthiness Directive was not properly performed, and inadequate inspection of the main rotor blades.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 21, 1997 · about 5:51 pm local time
- Place
- Miltonfreewater, Oregon · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH-12E · all UH-12Es on the register
- Registration
- N3005J · registry record · serial 5024
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
A witness reported that as he was watching the helicopter maneuver for the aerial application flight, one of the main rotor blades separated from the helicopter. The helicopter then nosed down and collided with the terrain. Examination of the separated sections of the main rotor blade found that the origin area contained a few crack arrest positions and small ratchet marks, indicating that fatigue cracking initiated from multiple locations. The thickness of the larger spar was measured and found to be slightly below the specified manufacturer's measurements. Scratches or scoring marks, similar to a sanded appearance, were noted on the lower surface where the thickness was reduced. The thickness of the spar wall continued to decrease further outboard of the fracture. Corrosion was also visible. The applicable Airworthiness Directive (AD) requires performance of inspections per the Service Bulletin (SB) to prevent main rotor blade failure due to cracking of the spar or delamination of the trailing edge skin from the spar. The SB specifies the different types of inspections to be accomplished, the intervals for accomplishment of the inspections, and how the inspections are to be performed to detect for cracks or delamination. The SB indicates that a chemical compound is to be used to strip the paint from the surface to accomplish the inspection. Maintenance records indicate that inspections were performed, however, no cracks were detected.
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; instructor: airplane single-engine; instrument: airplane; rotorcraft: helicopter
- Flight time: 7,950 hours in all; 3,200 in this make and model
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 4,196 hours
- Last inspection: annual inspection, July 10, 1996; 490 hours since
- Maximum gross weight: 2,750 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-540-C2A (piston); 0 hours total
The flight
- Departed from: ALW Walla Walla WA at 4:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 220° at 10 knots
- Visibility: 35 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 43°F (6°C)
- Altimeter: 29.00 inHg
- Observation at 5:50 pm from ALW, 10 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.
Other NTSB records under N3005J 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.