Hiller UH12E accident near Becker, Minnesota, July 6, 2022
On July 6, 2022 at about 3:15 pm local time, a 1965 Hiller UH12E (helicopter), registered N64272, was substantially damaged in an accident during maneuvering near Becker, Minnesota. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The in-flight failure of the main rotor mast hub due to several undetected fatigue fractures.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 6, 2022 · about 3:15 pm local time
- Place
- Becker, Minnesota · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH12E, built 1965 · all UH12Es on the register
- Registration
- N64272 · no longer on the register · serial 1679
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
While the pilot was conducting an aerial application flight, he felt a small jolt, the main rotor mast failed, and the helicopter collided with terrain. Four days before the accident, a mechanic performed a dye penetrant inspection on the rotor mast; the helicopter had only flown 9 hours since the inspection. Attempts to retrieve the rotor mast parts from the operator were unsuccessful and when contact was reestablished with the owner, he had already disposed of the parts. Photos of the broken rotor hub were reviewed by the National Transportation Safety Board (NTSB) Materials Laboratory, which determined that several preexisting, progressive cracks were present.
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
- Sys/Comp malf/fail (non-power) during maneuvering defining event
The NTSB's findings
- Aircraft › Aircraft propeller/rotor › Main rotor system › (general) › Failure
- Aircraft › Aircraft propeller/rotor › Main rotor system › Main rotor head system › Fatigue/wear/corrosion
Pilot
- Certificate: private
- Ratings: rotorcraft: helicopter
- Flight time: 5,957.8 hours in all
- Last flight review: April 1, 2022
- Medical certificate: Unknown
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 10,285.9 hours
- Last inspection: 100-hour inspection, July 2, 2022; 9.6 hours since
- Maximum gross weight: 2,750 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming VO-540-C2A (piston); 0 hours total
- Operator: Triple H Aviation
The flight
- Departed from: Becker MN
- Destination: Becker MN
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 050° at 5 knots
- Visibility: 10 statute miles
- Sky: overcast at 600 ft
- Temperature: 66°F (19°C), dew point 59°F (15°C)
- Altimeter: 30.06 inHg
- Observation at 10:07 am from KMGG, 11 miles away
Weather report (METAR): KMGG 061507Z AUTO 05005KT 10SM OVC006 19/15 A3006 RMK AO2
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on July 5, 2024. 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.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Record of Conversation Operator | PDF, 1 page | View Download |
| 2 | Record of Conversation FAA | PDF, 1 page | View Download |
| 3 | Photos | PDF, 5 pages | View Download |
| 4 | Maintenance Records | PDF, 3 pages | View Download |
| 5 | Maintenace Records Summary | PDF, 1 page | View Download |
| 6 | Hiller Airworthiness Directive 73-20-03 | PDF, 2 pages | View Download |
| 7 | NTSB Materials Lab | PDF, 6 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.