Mcdonnell Douglas 500E accident near Mount Zion, Kentucky, April 30, 1992
On April 30, 1992 at about 5:25 pm local time, a Mcdonnell Douglas 500E (helicopter), registered N97BR, was substantially damaged in an accident near Mount Zion, Kentucky. It was a public-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
AN IN-FLIGHT SEPARATION OF THE TAIL ROTOR ASSEMBLY AS THE RESULT OF THE LOSS OF AN ABRASION STRIP FROM THE LEADING EDGE OF ONE OF THE TAIL ROTOR BLADES, WHICH INDUCED VIBRATIONAL STRESSES HIGH ENOUGH TO INITIATE FATIGUE FAILURE IN THE TAIL ROTOR GEAR BOX MOUNTING STUDS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 30, 1992 · about 5:25 pm local time
- Place
- Mount Zion, Kentucky · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mcdonnell Douglas 500E
- Registration
- N97BR · no longer on the register · serial 145E
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
WHILE FLYING IN A CRUISE CONFIGURATION AT 1500 FEET MEAN SEA LEVEL, AND ABOUT 10 MINUTES INTO THE FLIGHT THE HELICOPTER STARTED TO VIBRATE. THE PILOT ELECTED TO MAKE A FORCED LANDING IN THE MOST SUITABLE AREA AVAILABLE. DURING THE DESCENT THE VIBRATION CONTINUED TO WORSEN. AT ABOUT 5 FEET ABOVE THE SELECTED LANDING SITE THE PILOT HEARD A LOUD BANG, THE HELICOPTER YAWED TO THE RIGHT AND PITCHED NOSE DOWN. THE PILOT LOWERED THE COLLECTIVE AND PUT THE HELICOPTER ON THE GROUND. METALLURGICAL EXAMINATION DETERMINED THAT THE LOSS OF THE ABRASION STRIP FROM THE LEADING EDGE OF TAIL ROTOR BLADE S/N 5086 INDUCED VIBRATIONAL STRESSES THAT WERE HIGH ENOUGH TO INITIATE FATIGUE FAILURE IN THE TAIL ROTOR GEAR BOX MOUNTING STUDS WHICH RESULTED IN THE SEPARATION OF THE GEAR BOX ASSEMBLY FROM THE HELICOPTER.
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, commercial pilot
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 5,750 hours in all; 500 in this make and model; 150 in the last 90 days; 50 in the last 30 days; 4,700 as pilot in command; 1,100 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 1,350 hours
- Last inspection: 100-hour inspection, January 2, 2000; 59 hours since
- Maximum gross weight: 3,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C-20D (turboshaft); 0 hours total
The flight
- Departed from: CVG Cincinnati OH at 5:10 pm
- Destination: CVG
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 25 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 | |||
| 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.