Hiller UH-12E accident near Brooten, Minnesota, July 5, 1983
On July 5, 1983 at about 1:00 pm local time, a Hiller UH-12E (helicopter), registered N4028K, was substantially damaged in an accident near Brooten, Minnesota. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 5, 1983 · about 1:00 pm local time
- Place
- Brooten, Minnesota
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH-12E · all UH-12Es on the register
- Registration
- N4028K · registry record · serial 5069
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
THE HELICOPTER HAD JUST LIFTED OFF OF THE FLATBED OF A TRUCK WHEN IT STARTED TO SPIN. THE PLT LOWERED THE COLLECTIVE, REDUCED THE POWER & LANDED BESIDE THE TRUCK. DURING TOUCHDOWN, THE MAIN ROTOR BLADES STRUCK THE TRUCK. AN INVESTIGATION REVEALED THAT THE THRUST BEARING, PN 25200-3, IN THE TAIL ROTOR DRIVE WAS INSTALLED BACKWARDS. THIS ALLOWED THE BEVELED DRIVE GEAR TO MOVE FORWARD & BECOME DISENGAGED FROM THE TAIL ROTOR DRIVE GEAR.
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; rotorcraft: helicopter
- Flight time: 3,260 hours in all; 360 in this make and model; 120 in the last 90 days; 3,200 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 545 hours
- Last inspection: annual inspection, April 15, 1983; 117 hours since
- Maximum gross weight: 3,100 lb
- Seats: 3
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: Brooten MN at 1:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 360° at 4 knots
- Visibility: 25 statute miles
- Sky: clear
- Temperature: 61°F (16°C), dew point 0°F (-18°C)
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.