According to a new report, the FAA mulls changing insulation standards, amending its controversial rule upgrading flammability standards for thermal and acoustic insulation. There is worry that the unexpected scope of the new ruling, effective on September 2, 2005, would put too much burden on business aircraft owners and operators.

At about the same time the rule was going into effect, representatives from several associations met with the FAA to discuss the new regulations, believing they pose “a serious threat to continued operation after September 2 of many in-service Part 25 [certified] aircraft.” The meeting, attended by representatives from the General Aviation Manufacturers Association (GAMA), NBAA and several other trade groups, raised concerns that the application of new rule is “broader than originally intended.â€?

The associations explained, “It has long been understood that the requirements of the final rules would apply solely to thermal and acoustic blankets installed in Part 25 airplanes.” However, they continued, in corresponding guidance material released June 24 “it became clear that the rule was being applied to every insulating material in the fuselage of every Part 25 airplane (both old and new) and every piece of installed equipment with insulation.”

Based on the feedback the associations received from business aircraft operators, the FAA has developed an “action plan” to ease the burden of the requirements of the rule for the “immediate short term,” said a GAMA official. The FAA sent Flight Standards Airworthiness (FSAW) Bulletins 05-09 and 05-10 (September 1 and 7, respectively) to field inspectors to guide them in the application of the retroactive portion of the rule– Part 91.613(b)(1) and 135.170(c)(1). The bulletins “give inspectors a better understanding of the rule and provide clarification on the scope,” according to the GAMA official.

First, the bulletins make it clear that the new flammability requirements for thermal and acoustic insulation apply only to material “installed in the fuselage of transport-category airplanes.” The rule applies only when insulation is being replaced, but “the insulation that is inaccessible in flight is what should be the focus of compliance.” The FAA determined that insulation accessible in flight “can be readily extinguished and therefore this insulation material does not have to meet Part 25.856″â€? (the new flammability certification standards).

According to the bulletin, insulation on specific items covered by the rule include insulation inside ovens, carts, refrigerator meal boxes and coffee makers. It goes on to say “Insulation ‘visible in the cabin’ is considered compliant. Insulation not in the fuselage is not covered by the rule. Such areas ‘include the empennage, wheel wells and wing-to-body fairings.’”