# SDR ALG2001F00001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 4, 2001
- Submitted: June 20, 2001
- Operation: Air carrier
- Aircraft: [N917AL](https://openairdocs.org/aircraft/N917AL), registered now
- Make and model: Bell 407
- Registry model: [Bell 407](https://openairdocs.org/model/bell-helicopter-textron-canada-407) (OpenAirDocs)
- Aircraft serial: 53381
- Engine: Allsn 250C47B
- System (JASC): [6310 · Engine/Transmission Coupling](https://openairdocs.org/jasc/6310)
- Part: Drive Shaft
- Part number: 206340300105
- Part serial: KC734
- Condition: Failed
- Location: Main Rotor
- Part time: 2,114 hours
- Stage of operation: CR
- How discovered: O
- Nature of condition: E, F
- Precautionary procedure: R
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ALG2001F00001

## Discrepancy

IN CRUISE FLIGHT.  VIBRATION IN AIRFRAME AND PEDALS INCREASING IN AMPLITUDE FROM SLIGHT TO EXTREME.  WHEN THE VIBRATION REACHED THE EXTREME LEVEL, POWER WAS LOST TO THE ROTOR SYSTEM AND THE AIRCRAFT WAS AUTOROTATED TO THE WATER.  INPUT DRIVESHAFT FAILED AND WAS FOUND COMPLETELY DECOUPLED AT THE TRANSMISSION INPUT ADAPTER.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.