Enstrom F28A accident near Napoleon, Ohio, February 3, 2001
On February 3, 2001 at about 4:30 pm local time, a Enstrom F28A (helicopter), registered N98PM, was substantially damaged in an accident near Napoleon, Ohio (Henry County airport). It was an other work-use flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The fatigue failure in the fillet radius of the mast, which resulted in the separation of the main rotor system.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 3, 2001 · about 4:30 pm local time · cases in 2001
- Place
- Napoleon, Ohio · Henry County · cases near this airport · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Enstrom F28A · all F28As on the register
- Registration
- N98PM · registry record · serial 200
- Damage
- Substantial damage
- Flight
- Other work-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The helicopter developed a vibration, and the pilot elected to return to the departure airport. On final approach to landing, approximately 10 feet above the ground, the main rotor mast fractured, and the main rotor system departed the helicopter. The pilot and two passengers were not injured. Examination of the fracture surfaces by a Safety Board metallurgist revealed the mast failed in fatigue in the area of the fillet radius. Microscopic examination revealed that a portion of the fatigue region had been painted over with paint that matched the exterior of the mast. The mast installed in the accident helicopter had a narrower fillet radius than masts subsequently produced by the manufacturer. An FAA Airworthiness Directive (AD) that required inspecting and strengthening of the fillet radius affected the narrower masts. As a result of this investigation, the FAA amended the AD to immediately retire some transmission/mast combinations, and to ultimately remove all of the narrower masts from service.
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; instructor: airplane single-engine; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 9,000 hours in all; 1,200 in this make and model; 150 in the last 90 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 1,732 hours
- Last inspection: annual inspection, February 2, 2001; 1 hours since
- Maximum gross weight: 2,150 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming HIO-360-C1A (piston); 0 hours total
The flight
- Departed from: 7W5 Napolean OH at 4:20 pm
- Flight plan: none
- Runway 10, 4,487 ft by 65 ft
Weather at the time
- Light: daylight
- Wind: from 180° at 11 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 4,800 ft
- Temperature: 19°F (-7°C), dew point 10°F (-12°C)
- Altimeter: 30.27 inHg
- Observation at 4:52 pm from TOL, 17 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 2 |
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.
Connections how this case links to the rest of the register
- N98PM on the register today · the tail number may have moved to another aircraft since
- Enstrom F-28 147 registered today · the model family and its accident history
- Enstrom 215 aircraft on the register
- Engine: Lycoming HIO-360-C1A 6 aircraft carry this series today · as the NTSB recorded it
- Henry County · nearest airport
- Accidents and incidents in Ohio 1,884 since 1982 · 253 in the last ten years
- Ohio 8,531 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/IAD01LA031.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.