AC 90-100A may change all that

FAA Policy Change Voids Many IFR GPS Units
Numerous previously IFR-certified GPS receivers might now be unapproved for flying many instrument procedures due to recent FAA policy changes, according to AOPA.
May 25, 2:57am UTC

FAA Policy Change Voids Many IFR GPS Units
By Chad Trautvetter, Editor In Chief

Numerous previously IFR-certified GPS receivers might now be unapproved for flying many instrument procedures due to recent FAA policy changes, according to AOPA. On Thursday, the association said the FAA’s Advisory Circular 90-100A, issued in March, indicates that only three GPS models – the Garmin 400, 500 and G1000 series – are now legal. Other models made by Garmin, including the new GNS 480 WAAS receiver, as well as receivers manufactured by Chelton, Honeywell, Northstar, and Trimble are listed as “noncompliant,” AOPA said. (Click here for a more comprehensive compliance list.) AOPA said the the FAA has committed to work to resolve the pilot group’s concerns over these policy changes. The action, as it now stands, means up to 26,000 GPS users no longer comply with a 1996 FAA policy that allows GPS to be used in lieu of ADF or DME.

Yes, your tax dollars hard at work. From what I understand, this was a bureaucratic screw-up and the voided GPS units should be recertified within a month or so. Note that the Garmin GPSs were among the few not voided. In the mean time, you can fly all of the same approaches if you have DME and ADF on board in addition to GPS (how is that for a great leap backward?).

Relief for IFR-certified GPS owners
FAA clarifies policy after AOPA points out problem

Older IFR-certified GPS receivers (and many new ones) are OK to use as they were intended, thanks to a clarification of the rules sought by AOPA. A previous interpretation by the FAA had caused a panic among some 26,000 users.

The FAA has begun tying up a number of loose ends created when it revised policies that instruct pilots on how to use GPS receivers when flying under IFR. In a letter to the FAA, AOPA had drawn the agency’s attention to the consequences of the combined changes to the Aeronautical Information Manual (AIM), an advisory circular (AC 90-100A) on terminal and en route area navigation (RNAV) operations, and an associated list of compliant GPS units.

“The bottom line is pilots can continue using their IFR GPS receivers like before,” said Randy Kenagy, AOPA senior director of strategic planning.

In a June 1 letter to AOPA, the FAA confirmed that pilots can use appropriate GPS receivers (TSO-C129/129a) in lieu of ADF or DME. It also lets them continue using T routes, which allow properly equipped general aviation aircraft to safely transition through some of the busiest airspace in the nation and access some remote areas where no other ground-based navigation equipment exists.

“The FAA’s letter provides some much-needed relief to pilots who’ve installed expensive GPS receivers in their aircraft,” said Kenagy. "It makes it clear that the current operational approvals will be in place for a long time to come.

“But it also says that as system evolves to RNAV and required navigational performance (RNP), certain older receivers will not be allowed to be used for RNAV standard instrument departure and arrival routes (SIDs and STARs). AOPA will work with the FAA to ensure that members are not penalized for not having RNAV SID/STAR-capable equipment.”