FTW98TA104 · Hughes 269C
Hughes 269C · Accident: airframe, component or system failure en route
From BACON RANCH, TX to an unrecorded destination
Narrative check · The NTSB narrative appears to contradict this record's flight rules. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- FTW98TA104
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Government
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Hughes 269C
- Aircraft type
- Hughes 269
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N1093N
- Operator
- Gary L. Nunley · private individual
- Onboard fatalities
- Unknown
- Route
- From BACON RANCH, TXTo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Public Aircraft Narrative disagrees
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Lubricant, grease › Loss, total
- Rotor drive system › Failure
- Rotor drive system, engine to transmission drive › Disconnected
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot and a crewmember/gunner of the public use helicopter reported hearing a loud squealing noise, emanating from the rear of the helicopter, while in flight at 75 feet AGL. Rotor RPM began decaying from 3,100 to approximately 2,000 RPM, and the pilot initiated an autorotation. During the landing, the main rotor blades contacted the ground, and helicopter came to rest in a rocky dry creek bed on its right side. The tension nut for the short shaft was found upstream from the point of impact. An examination revealed that splines for the drive shaft coupling were damaged, and the plating on the adapter was discolored as result of excessive heat. Further examination revealed that the damage sustained by the shaft and adapter were consistent with loss of grease and subsequent overheating and destruction of the drive splines. The forward rubber boot, used to retain the lubricant, had separated, resulting in the loss of lubrication.
Probable cause
failure of splines on the drive shaft coupling after separation of the forward bubber boot and loss of lubrication (grease), which resulted in a disconnect of the rotor drive system and an autorotation/forced landing. Lack of suitable terrain in the forced landing area was a related factor.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW98TA104
- Event ID
- 20001211X09449
- Case number
- FTW98TA104
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 438819284a1100c8714d2c46177599584235a6495ce5de73c9d105b9a03df4ea; retrieved 2026-09-21T20:57:18.140Z.
- Corrected after a review of the NTSB narrative, which states these values explicitly: operation. The narrative states "The pilot and a crewmember/gunner of the public use helicopter reported hearing a loud squealing noise"; the flight was a public aircraft operation, not Part 91 general aviation.