VOR navigation loop antenna

FAA Aircraft Certification Service SPECIAL AIRWORTHINESS INFORMATION BULLETIN http://www.faa.gov/aircraft/safety/alerts/SAIB

SAIB: SW-07-34 Date: May 29, 2007 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin alerts you, owners and operators of Agusta S.p.A Model A109E rotorcraft, of VOR navigation loop antenna failures due to high temperature and vibration.

Background

Several operators of Agusta Model A109E rotorcraft have reported failures of one element of the VOR navigation loop antenna. These failures occurred with the Dorne and Morgolin P/N DMN 48-1 antennas, and were attributed to high temperature and vibration. Although this failure mode does not result in an inoperative VOR antenna, pilots should be aware that it does result in reduced sensitivity of the VOR navigation antenna. A total loss of the VOR signal would be annunciated by the HSI flag, which does not occur with this type of antenna failure mode.

Recommendations

Agusta has developed a new replacement antenna (P/N DMN48-5) which has been developed and certified to operate in higher temperature and vibration environments. The DMN48-5 antenna is fully interchangeable with the existing DMN48-1 antenna. We recommend that all operators of the A109E rotorcraft install the DMN48-5 VOR antenna.

For Further Information Contact

Carroll Wright, Aerospace Engineer, FAA Rotorcraft Directorate, ASW-111, 2601 Meacham Blvd., Fort Worth, Texas 76137; phone (817) 222-5120; fax (817) 222-5961; email: [email protected].