Report: “Polished Frost” Is Not A Safe Concept

The FAA needs to change its rules to encourage pilots to totally clean frost from their aircraft’s wings before takeoff, rather than just smooth it out to remove the bumps, according to a safety recommendation from Britain’s Department for Transport. The recommendation was prompted by the investigation into the crash of a U.S.-owned and operated Bombardier CL-600 that crashed in the U.K. in 2002, under circumstances similar to last week’s crash of a CL-600 in Colorado that killed three people. FAR Part 91.527 says pilots must remove frost from the wings and other aerodynamic surfaces “unless that frost has been polished to make it smooth.” The British report says it’s not clear exactly how pilots should “polish” the frost, and that the rule may give the pilots the impression that some amount of frost is acceptable. “The concept of ‘Polished Frost’ is particularly inappropriate and potentially dangerous to modern aircraft types and detracts from the importance of strictly observing the clean wing principle,” the report says. A safety recommendation was issued to the FAA, suggesting that they should delete all reference to “Polished Frost” in the regs and ensure that the term is expunged from operations manuals.

Meanwhile, the publicity from last week’s Colorado accident has apparently alerted not only pilots but commercial air passengers to the dangers of icing. An American Connection flight out of Columbia, S.C., was delayed last week when passengers complained to the flight crew that they could still see ice on the wings, after a crew had finished cleaning them and the airplane was preparing to depart. The wings were re-cleaned before the flight took off.