IAD05LA046 · Schweizer 269C
Schweizer 269C · Accident: airframe, component or system failure while maneuvering
From Mallory Airport (WV12) to Logan County Airport (6L4)
Event
- NTSB case
- IAD05LA046
- 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
- Unknown
- 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
Schweizer 269C
- Aircraft type
- Schweizer 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
- N61193
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Mallory Airport (WV12), S. Charleston, WVTo Logan County Airport (6L4), Logan, WV
- 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
- Maneuvering
- 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
- 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
- Substantial
Cause areas
- Manufacturer › Maintenance, replacement, not performed
- Rotor drive system, engine to transmission drive › Fatigue
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
While investigating a fire, the pilot noticed an "unusual vibration," and a "needle split" on the rpm gauge. The rotor speed began to decay and the engine speed began to increase. The pilot then entered an autorotation. The helicopter, impacted terrain, was substantially damaged, and a passenger was seriously injured. Examination of the drive train revealed that the main drive pinion, which drove both the main rotor assembly and the tail rotor drive shaft, had failed in fatigue that had initiated in the root of the first (most forward) engaged pinion thread. The failed pinion had been in service for 4,055.4 hours. Including the accident pinion, 10 instances of pinion failures were identified during the investigation. Times in service ranged from 261.5 to 4,243 hours. According to the manufacturer, life limits for the pinion ranged from 6,000 to 8,000 hours depending on application. As a result of this investigation, The FAA issued an SAIB alerting owners and operators of pending revisions to the inspection procedures for the pinion. The manufacturer revised its Handbook of Maintenance Instructions, to include the revised inspection procedures, and submitted design revisions to the FAA to make the part more robust.
Probable cause
A fatigue fracture of the main transmission drive pinion. Also causal was the manufacturer's failure to remove the affected pinions from service during the period that transpired between the initial failures and the accident flight.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record IAD05LA046
- Event ID
- 20050330X00381
- Case number
- IAD05LA046
- 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, coordinates. 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: 332ac9cd9ea9ea2ddde7dbce8f6be1bf65225a1bb9b61efe72808d9e730e597b; retrieved 2026-09-21T09:09:08.369Z.