FTW01LA005 · Holt THORPE T-18C THORPE T-1
Holt THORPE T-18C THORPE T-1 · Accident: propeller failure/malfunction en route
From Roy Hurd Memorial Airport (E01) to an unrecorded destination
Event
- NTSB case
- FTW01LA005
- 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
- 2 · 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
- General aviation
- 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
Holt THORPE T-18C THORPE T-1
- Aircraft type
- Holt THORPE T-18C
- Category
- Airplane
- 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
- N85LH
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Roy Hurd Memorial Airport (E01), Monahans, 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
- Part 91: General Aviation
- 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
- Propeller failure/malfunction
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Propeller system/accessories, blade › Corroded
- Propeller system/accessories, blade › Fatigue
- Propeller system/accessories, blade › Separation
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
According to witnesses, the amateur-built experimental airplane was in cruise flight between 1,500 and 2,500 feet agl, when they heard a loud noise and observed pieces of the airplane separate from the airframe. Subsequently, the airplane entered a descent and impacted the ground. A fire erupted and consumed the airplane. Examination of the airplane revealed that a propeller blade separated 14.5 inches from the butt end. The blade failed due to fatigue initiating from an intergranular corrosion crack. According to the manufacturer's recommended interval between overhauls, the blade was four years overdue for an overhaul. An overhaul could have detected the corrosion crack that led to the failure. Additionally, each blade had been shortened approximately 6 inches since it was originally manufactured, and the propeller was not approved by the manufacturer for installation on the type of engine in the airplane.
Probable cause
the failure of the propeller blade due to fatigue, which originated from a corrosion crack. A contributory factor was the pilot/owner's failure to ensure that the propeller was overhauled at the manufacturer's recommended interval.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW01LA005
- Event ID
- 20001212X22156
- Case number
- FTW01LA005
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- 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: 26c1f931daf26fc57f6165c025e0cb4937c76332ff4f99937503e311912fb509; retrieved 2026-09-20T20:49:56.633Z.