FAA rescinds known icing interpretation at AOPA's request

September 25, 2008

After two years of waiting, the FAA has finally acceded to AOPA’s request to rescind a letter of interpretation on known icing, saying it was published in error. But even with the old interpretation invalidated, the agency says it will be at least another month before pilots can expect new guidance.

AOPA was concerned that the FAA’s 2006 letter of interpretation identified relative humidity as a factor in determining known icing conditions, a factor that could ground many GA pilots even when no visible moisture is present. The association wrote to the FAA in November 2006, asking the agency to rescind the letter.

The following spring, the FAA responded with a new draft interpretation. Again AOPA commented, this time urging the FAA to consider a pilot’s entire decision-making process, not just whether he or she experiences ice buildup, when deciding whether to take enforcement action. But that draft interpretation never was finalized, leaving the original 2006 interpretation in place.

Finally, on Sept. 22, the FAA rescinded its original interpretation. But the agency has not yet provided a new interpretation of the regulation.

In a letter to AOPA, FAA officials said they expected to issue a new interpretation in October, but considering the long history of dispute over the meaning of this regulation, pilots may have to wait even longer for official guidance.