# SDR 97ZZZX4406

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 30, 1997
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N407AL](https://openairdocs.org/aircraft/N407AL), registered now
- Make and model: Bell 407
- Registry model: [Bell 407](https://openairdocs.org/model/bell-helicopter-textron-canada-407) (OpenAirDocs)
- Aircraft serial: 53044
- System (JASC): [6220 · Main Rotor Head](https://openairdocs.org/jasc/6220)
- Part: Frahm Damper
- Part number: 407010150103
- Condition: Damaged
- Location: Main Rotor Hub
- Part time: 920 hours
- Stage of operation: IN
- Nature of condition: E
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/97ZZZX4406

## Discrepancy

PILOT REPORTED A ONE-TO-ONE VIBRATION.  WHILE WORKING ON THE ROTOR VIBRATION, THE FRAHM DAMPER WAS FOUND DAMAGED.  UPON REMOVING MAIN ROTOR COVER ASSEMBLY, NOTED ITEM 32 (LINER ASSEMBLY) HAD EXCESSIVE CONTACT WITH ITEM 17 (PAD ASSEMBLY).  LINER ASSEMBLY WAS BROKEN INTO NUMEROUS PIECES.  PAD ASSEMBLY WAS ALSO EXCESSIVELY DAMAGED.  THE UPPER FLANGES ON ITEM 18 (WEIGHT ASSEMBLY) CONTACTED THE RADIUS AREA OF ITEM 34 (HOUSING ASSEMBLY) TO A POINT WHICH CAUSED THE HOUSING ASSEMBLY TO BE GOUGED AND CRACKED IN THE RADIUS AREA.

---
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.