Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-09-47
August 7, 2009
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) is being
transmitted to owners and operators of aircraft equipped with Garmin
G1000, Perspective™, Prodigy™ Integrated Flight Decks installed with a
Garmin GFC 700 autopilot. The purpose of this SAIB is to inform pilots
of an issue that has been brought to the FAA’s attention with the
navigational radio auto-tune feature while performing a VOR or ILS
Approach.
The airworthiness concern is not an unsafe condition that would warrant
airworthiness directive (AD) action under Title 14 of the Code of
Federal Regulations (14 CFR) Part 39.
Background
Changes to navigation frequencies that occur between navigation
database cycle distributions may cause a mismatch between the
automatically tuned LOC/ILS frequency and the frequency shown on the
approach chart or applicable NOTAM. In these cases, the mismatched
(incorrect) automatically tuned frequency may cause the HSI to
automatically slew to the wrong course.
Recommendations
Pilot Action: If the auto-tuned LOC/ILS frequency does not correspond
to the frequency shown on the approach chart or applicable NOTAM, the
FAA recommends that the pilot:
Manually tune the navigation receiver to the correct LOC/ILS frequency (On the approach chart or NOTAM).
Assure that the correct inbound course is selected.
Manually fly the approach.
Or choose a different terminal procedure.
The GFC 700 will not capture, track, or give flight director commands for a manually selected course.
Garmin is planning resolution to this issue with GDU software version
10.00 and later versions will provide capability to couple the
autopilot to the VOR or LOC/ILS approach when the pilot manually tunes
the correct frequency and manually selects the proper course for the
approach.