FTW99FA148 · Beech C18S
Beech C18S · Accident: propeller failure/malfunction en route
From Jack Brooks Regional Airport (BPT) to Springdale Municipal Airport (ASG)
Event
- NTSB case
- FTW99FA148
- 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
- 1 · 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
Beech C18S
- Aircraft type
- Beechcraft 18
- 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
- N9729H
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Jack Brooks Regional Airport (BPT), Beaumont, TXTo Springdale Municipal Airport (ASG), Springdale, AR
- 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
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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 › Cracked
- Propeller system/accessories, blade › Fatigue
- Propeller system/accessories, blade › Separation
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During a cross-country flight, the pilot of the twin-engine airplane reported to air traffic control that he has 'lost an engine.' A witness observed the right engine hanging from its lower mounts as the airplane turned right and headed towards the nearest airport. The airplane impacted trees approximately 1 mile short of the runway threshold. Examination of the right engine propeller revealed that one of its blades was separated about mid-span. The separated tip section of the blade was not recovered. Metallurgical examination of the fracture surface revealed that the blade failed as a result of a fatigue crack that originated from corrosion pits on the camber surface (face) of the blade. The failed blade was examined approximately 6 hours prior to the accident in accordance with an airworthiness directive (AD 81-13-06 R2) that called for inspections of the blade for corrosion and fatigue. However, the inspections called out in the AD were only applicable to the blade fillet and shank regions, well inboard of the fracture location on the failed blade. Overhaul of the propeller in accordance with the propeller manufacturer's manual includes grinding of each blade to 'remove all visual evidence of corrosion.' According to the airplane's owner, the propellers had not been overhauled in the eight years that he had owned the aircraft. The maintenance records were destroyed in the accident, which precluded determination of the date and time of the last propeller overhaul. The accident airplane was being operated under Title 14 CFR Part 91, and therefore, the propellers were not required to be overhauled at specified intervals.
Probable cause
the separation of a propeller blade in cruise flight as a result of fatigue cracking emanating from surface corrosion pitting.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW99FA148
- Event ID
- 20001212X18762
- Case number
- FTW99FA148
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1999-05-24.
- API snapshot SHA-256: 94d5b0ae4f9114e6da4419513120f158b8f24ac6a99423ac778cb4f9bdf3a1ac; retrieved 2026-09-20T22:06:35.342Z.