ERA11LA204 · Robinson R22 BETA
Robinson R22 BETA · Accident: powerplant system/component malfunction/failure en route
From 26NK · Hamptonburgh, NY to Greenwood Lake Airport (4N1)
Narrative check · The NTSB narrative appears to contradict this record's location. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- ERA11LA204
- 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
Robinson R22 BETA
- Aircraft type
- Robinson R22
- 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
- N259TW
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 26NK · Hamptonburgh, NYTo Greenwood Lake Airport (4N1), West Milford, NJ
- 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
- Defining eventThe 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
- Powerplant system/component malfunction/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
- Aircraft › Aircraft propeller/rotor
- Personnel issues › Action/decision
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
According to the pilot, following clutch engagement after engine start and warm up, it took 20 to 25 seconds for the main rotor to start turning. About 15 minutes into the flight and while cruising at 700 feet above ground level, the pilot heard a “flapping” noise and smelled burning rubber. He then “sensed” that the engine was losing power, observed numerous caution lights illuminate, and entered an autorotation. The helicopter subsequently impacted uneven terrain, which resulted in damage to the fuselage, as well as the main and tail rotor blades. Postaccident examination found that both power transmission belts had been ripped, mostly through the center of the backing, separating the two sides of the belt. A review of maintenance records showed that an airframe overhaul was completed about 4 months before the accident, which included replacement of both v-belts.According to the manufacturer’s maintenance manual, a delay of more than 5 seconds between clutch switch engagement and rotor turning indicates excessive belt slack. Power transmission belts that are too loose can jump out of their grooves during start up and jump forward into the next groove or off the forward edge of the pulley. The pre-engine start checklist instructs pilots to adjust the slack of the power transmission belt system so that the rotor begins turning within 5 seconds of clutch engagement. Evidence suggests that the pilot did not perform the recommended check.
Probable cause
The pilot’s failure to adhere to published preflight checklist limitations and procedures, resulting in excessive slack and subsequent failure of the power transmission belts and a total loss of rotor system drive.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA11LA204
- Event ID
- 20110322X24645
- Case number
- ERA11LA204
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: 2862d46fd8873aa4335a1355b8b5cacf13d6c3ba1f32c5f831a6d1ccef76890a; retrieved 2026-09-15T15:57:13.338Z.