Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
SW-07-34
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.