Beech H35 accident near Green Lake, Wisconsin, July 25, 2010
On July 25, 2010 at about 5:30 pm local time, a Beech H35, registered N5443D, was substantially damaged in an accident during enroute (descent) near Green Lake, Wisconsin. It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A total loss of engine power during descent due to the overhaul facility’s inadequate maintenance.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 25, 2010 · about 5:30 pm local time
- Place
- Green Lake, Wisconsin · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech H35 · all H35s on the register
- Registration
- N5443D · no longer on the register · serial D-4991
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, while on approach to the destination airport, the engine experienced a total loss of power. He selected an uphill-sloped soybean field to make a forced landing and retracted the landing gear. The airplane slid 260 feet before coming to a stop. The airplane sustained firewall damage during the landing sequence. The postaccident investigation revealed several anomalies with the engine that were not in accordance with engine manufacturer's recommended maintenance practices. The No. 2 bearing was dislodged/separated and remnants of it were most likely the metallic debris found in the oil sump and oil filter. The cylinder thru-bolts were found to be tight; however, 19 of the 36 cylinder deck stud nuts were loose. A crack was observed between the No. 4 main bearing saddle on the left half of the crankcase, which extended through the No. 5 main bearing saddle. The pilot reported that the airplane had undergone a top overhaul about 18 flight hours prior to the accident. At the conclusion of the examination, the exact cause of the engine failure could not be definitively identified.
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
- Loss of engine power (total) during enroute (descent) defining event
- Collision with terrain or object (not controlled flight into terrain) during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Power plant › (general) › Failure
- cause Aircraft › Aircraft handling/service › Maintenance/inspections › (general) › Incorrect service/maintenance
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 1,206 hours in all; 116 in this make and model; 19 in the last 90 days; 19 in the last 30 days
- Last flight review: July 20, 2010
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 4,126 hours
- Last inspection: annual inspection, July 20, 2010; 19 hours since
- Maximum gross weight: 2,900 lb
- Seats: 4
- Landing gear: retractable
- Engine: Cont Motor O-470-G-C1 (piston); 0 hours total
The flight
- Departed from: PDC Prairie Du Chie WI at 4:45 pm
- Destination: OSH Oshkosh WI
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 110° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 55°F (13°C)
- Altimeter: 30.11 inHg
- Observation at 5:53 pm from OSH, 31 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 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.