Hughes 269C accident near Mohawk, Tennessee, November 14, 1988
On November 14, 1988 at about 5:17 pm local time, a Hughes 269C (helicopter), registered N9575F, was destroyed in an accident near Mohawk, Tennessee (Cooper Field). It was an instructional flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 14, 1988 · about 5:17 pm local time
- Place
- Mohawk, Tennessee · Cooper Field · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 269C · all 269Cs on the register
- Registration
- N9575F · no longer on the register · serial 440295
- Damage
- Destroyed
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE HELICOPTER HAD LANDED AT A PRIVATE AIRSTRIP AND THE INSTRUCTOR DEPLANED. THE DUAL STUDENT REMAINED IN THE HELICOPTER WITH THE ENGINE RUNNING. THE CFI REBOARDED AND THE STUDENT MADE THE TAKEOFF. LATER, ON DOWNWIND IN TRAFFIC PATTERN, A WITNESS REPORTED A LOUD NOISE FROM THE ENGINE. THE MAIN ROTOR WAS OBSERVED TO SLOW NOTICEABLY AND THE HELICOPTER ENTERED A VERY STEEP DESCENT, IMPACTING THE GROUND ABOUT 1,000 FEET SOUTH OF THE RUNWAY. THE ENGINE ROD BOLTS ON THE NUMBER FOUR CYLINDER HAD FRACTURED. EXAMINATION OF THE FLIGHT CONTROLS REVEALED NO EVIDENCE OF PREIMPACT FAILURE. ONE OF THE ROD BOLTS WAS METALLURGICALLY EXAMINED AND SHOWED CRACKING THROUGH 25 PERCENT OF THE BOLT. THE FATIGUE WAS ATTRIBUTED TO INSUFFICIENT PRELOAD ON THE BOLT. THE ENGINE HAD 813 HRS SINCE A MAJOR OVERHAUL AND 36 HRS SINCE ANNUAL 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: instructor: helicopter; rotorcraft: gyroplane; rotorcraft: helicopter
- Flight time: 756 hours in all; 604 in this make and model; 107 in the last 90 days; 53 in the last 30 days; 694 as pilot in command; 207 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 6,170 hours
- Last inspection: annual inspection, April 21, 1988; 36 hours since
- Maximum gross weight: 2,050 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming HI0-360-D1A (piston); 0 hours total
The flight
- Departed from: PVT Morristown TN
- Flight plan: none
- Runway 27, 2,250 ft by 50 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 55°F (13°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.
Other NTSB records under N9575F 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.