Changes To AIM, Advisory Circular Raised Concerns

This just in from the FAA: pilots may continue to use their IFR-approved GPS units for instrument approaches, at least for now.

The Aircraft Owners and Pilots Association tells ANN on Friday, the FAA began to close the lid to the Pandora's Box of questions stemming from the agency's recent revision to policies that instruct pilots on how to use GPS units when flying under instrument flight rules.

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 on terminal and en route area navigation (RNAV) operations (AC 90-100A), and an associated list of compliant GPS units.

"The bottom line is pilots can continue using their IFR GPS units like before," said Randy Kenagy, AOPA's senior director of strategic planning.

In a letter to AOPA on Friday, the FAA confirmed pilots' ability to use appropriate GPS units (TSO-C129/129a) in lieu of  an automatic direction finder (ADF) or distance measuring equipment (DME) -- 1930s and 1950s technology, respectively.

As ANN reported, a recent change to the AIM had raised questions about pilots' authorization to make the GPS substitution.

"This is an important step that ensures pilots' ability to use IFR GPS," Kenagy said. "In addition to allowing them to use GPS in lieu of ADF and DME, it lets them continue using T-routes."

T-routes, or Tango routes, 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 units in their aircraft," said Kenagy. "It makes clear that the current operational approvals will be in place for a long time to come.

"But the letter makes clear that as system evolves to RNAV and required navigational performance (RNP), certain older units will not be allowed to be used for RNAV standard instrument departure and arrival routes (SIDs and STARs)," Kenagy cautioned. "AOPA will work with the FAA to ensure that members are not penalized for not having RNAV SID/STAR-capable equipment."

FMI: www.aopa.org, www.faa.gov