Bell UH-1H accident near Chicago, Illinois, June 30, 2006
On June 30, 2006 at about 5:00 pm local time, a Bell UH-1H (helicopter), registered N681FD, was substantially damaged in an accident near Chicago, Illinois. It was a public-use flight (local) under public-use (government) rules. 3 people had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The in-flight separation of a tail rotor driveshaft hanger bearing due to inadequate maintenance performed by maintenance personnel. Contributing to the accident was the inability to maintain directional control due to the lack of tail rotor thrust.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 30, 2006 · about 5:00 pm local time
- Place
- Chicago, Illinois · map
- Type
- Accident
- Injuries
- 3 people had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell UH-1H · all UH-1Hs on the register
- Registration
- N681FD · registry record · serial 65-10101
- Damage
- Substantial damage
- Flight
- Public-use flight (local) · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
The public-use helicopter was responding to an emergency when it had a vibration and yawed to the right during cruise flight. It subsequently had a loss of tail rotor thrust. The pilot reduced engine power and made an autorotation to a park along the lakeshore. During landing flare, the helicopter yawed left as the pilot increased collective prior to touchdown. He stated that the touchdown "seemed smooth" and was made on the aft-portion of the skids, but as the helicopter slowed the left yaw tendency increased. The helicopter rolled over and came to rest inverted at the completion of the run-on landing. Examination of the helicopter revealed that the number-one tail rotor driveshaft hanger assembly had separated, resulting in a discontinuity of the tail rotor driveshaft. The machine bolt that held the assembly together was not installed with the required cotter pin. Further examination of the hanger assembly revealed that the splined areas did not contain grease. The remaining tail rotor driveshaft hanger bearings were properly greased and assembled. The mechanic who worked on the helicopter reported that due to other workload items, the previous tail rotor driveshaft inspection was interrupted several times before he was able to complete all of the required tasks. To avoid inter-mixing the driveshaft components, he temporarily reassembled the hanger assemblies before working on other projects. His intention was to disassemble each hanger bearing when he had the opportunity to complete the inspection. The mechanic stated that he must have forgotten to disassemble, inspect, and grease the number one hanger assembly. At the time of the accident, the number one hanger assembly had accumulated about 33 hours since the inspection.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane; rotorcraft: helicopter
- Flight time: 1,814 hours in all; 200 in this make and model; 20 in the last 90 days; 5 in the last 30 days; 1,753 as pilot in command
- Last flight review: January 1, 2006
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: minor injuries
Co-pilot
- Certificate: commercial pilot, private
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 329 hours in all; 3 in this make and model; 32 in the last 90 days; 2 in the last 30 days
- Last flight review: April 1, 2006
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 5,278 hours
- Last inspection: approved inspection programme, June 1, 2006; 6 hours since
- Maximum gross weight: 9,500 lb
- Seats: 8
- Landing gear: fixed
- Engine: Honeywell International Inc. T53-L-13BA (turboshaft); 0 hours total
The flight
- Departed from: LL35 Chicago IL at 4:50 pm
- Destination: LL35 Chicago IL
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 220° at 8 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 12,000 ft
- Temperature: 81°F (27°C), dew point 55°F (13°C)
- Altimeter: 30.06 inHg
- Observation at 4:53 pm from MDW, 7 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | 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.
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.