Hiller UH-12E accident near Hudsonville, Michigan, September 28, 1989
On September 28, 1989 at about 11:45 am local time, a Hiller UH-12E (helicopter), registered N4028T, was substantially damaged in an accident near Hudsonville, Michigan. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE FATIGUE FAILURE OF ONE OF THE TENSION-TORSION PINS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 28, 1989 · about 11:45 am local time
- Place
- Hudsonville, Michigan · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH-12E · all UH-12Es on the register
- Registration
- N4028T · registry record · serial 5097
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
APPROXIMATELY 10 MINUTES AFTER TAKEOFF AT AN ALTITUDE OF 300 FT AGL AND AN AIRSPEED OF 60 KTS, THE PILOT EXPERIENCED A SEVERE VIBRATION AND A DECREASE IN RESPONSE TO CONTROL INPUTS. THE PILOT ENTERED AN AUTOROTATION AND WHEN APPROXIMATELY 10 - 15 FT AGL, THE TAIL BOOM WAS SEPARATED BY THE MAIN ROTOR. THE HELICOPTER THEN DESCENDED, NOSE FIRST, TO TERRAIN IMPACT. INSPECTION REVEALED A TENSION-TORSION PIN HAD FAILED AT THE DRAG BRACE BOLT HOLE. PRE-EXISTING CRACKS WERE FOUND EXTENDING FROM THE PIN SHANK TO THE BOLT HOLE.
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: airline transport pilot, flight instructor
- Ratings: single-engine land; instructor: helicopter; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 8,900 hours in all; 220 in this make and model; 120 in the last 90 days; 34 in the last 30 days; 8,800 as pilot in command; 444 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 1,197 hours
- Last inspection: annual inspection, February 18, 1989; 77 hours since
- Maximum gross weight: 3,100 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-540-C2A (piston); 0 hours total
The flight
- Departed from: NONE Byron Center MI at 11:30 am
- Destination: NONE Hudsonville MI
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 210° at 7 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 46°F (8°C), dew point 39°F (4°C)
- Altimeter: 30.00 inHg
- Observation at 11:50 am from GRR, 18 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 N4028T 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.