Aerospace Industries Association of America **1000 Wilson Blvd., Suite 1700, Arlington, VA 22209 Tel (703) 358-1000 Fax (703) 358-1011**  **Internet: http://www.aia-aerospace.org** General Aviation Manufacturers Association **1400 K Street N.W., Suite 801, Washington, DC 20005 Tel (202) 393-1500 Fax (202) 842-4063**  **Internet: http://www.GAMA.aero** August 31, 2010

Docket Operations, M-30 (Docket# FAA-2010-0636) U.S. Department of Transportation 1200 New Jersey Avenue SE, Room W12-140, West Building Ground Floor, Washington, DC 20590-0001

SUBJECT: AIA/GAMA Request for Comment Period Extension, NP RM 10-10

Aerospace Industries Association (AIA) and General Aviation Manufacturers Association (GAMA) are requesting an extension to the comment period for N PRM 10-10, Airplane and Engine Certification Requirements in Supercooled Large Drop, Mixed Phase , and Ice Crystal Icing Conditions in accordance with 14CFR§11.47. AIA and GAMA represent the vast m ajority of the industry that is affected by this proposed regulation.

The NPRM includes reference to 5-guidance documents which detail how compliance to this rule can be achieved. As of this request, only 3 of 5 document s have been released for comment. As the NPRM is being published in connection with this new guidanc e, the requirement does not stand on its own and, therefore, it is not possible to determine the comp lete impact of the proposal. Although the initial 62-day comment has been extended by 30 days, the availabil ity of the guidance material remains critical to a thorough review and response from the industry. Fin ally, because the proposed rule differs in some are as from the ARAC recommendations, thorough review by t he entire industry is necessary. AIA and GAMA request the comment period for NPRM 10-10 be extend ed for 60-days after all guidance referenced in the proposed rule has been published for public review and comment.

The FAA is proposing a regulation which will have di rect effect on a significant portion of aviation manufacturers. The requirements being proposed are not specific and, therefore, the FAA is issuing accompanying guidance material along with the regul atory text in the NPRM. Because the requirements o f the NPRM do not stand on their own, but rather must be understood through companion guidance material, the industry cannot fully evaluate the impact of th is regulation without reviewing all associated guid ance. The NRPM states that the following guidance document s will be published in support of this proposed regulation:

 AC 25-XX, Compliance of Transport Category Airplanes with Cer tification Requirements for Flight in Icing Conditions . (Available for Comment on 7-30-2010)

 Revision to AC 20-147, Turbojet, Turboprop, and Turbofan Engine Induction Sys tem Icing and Ice Ingestion . (Not Available for Comment as of 8-30-2010) GAMA 10-34AIA/GAMA Request for Comment Period Extension, NPRM 10-10 August 31, 2010

 Revision to AC 25-25, Performance & Handling Characteristics in Icing, Pa rt 25 Appendix C

. (Not Available for Comment as of 8-30-2010)

 Revision to AC 25.629-1A Aeroelastic Stability Subs tantiation of Transport Category Airplanes. (Available for Comment on 8-11-2010)

 Revision to AC 25.1329-1B, Approval of Flight Guidan ce Systems (Available for Comment as of 6-6-2010)

As of August 30 th , 2010, several key guidance documents have not bee n made available for review and comment. AIA and GAMA understand some key technica l features, which will define the regulations, will be included in this missing guidance. For instance, there is question as to how radome ice shape inges tion for SLD conditions will be addressed. Depending on the guidance material, the regulation will have significantly different implications. In order for the affected industry to have a fair opportunity t o understand the proposed regulation so we can provide appropria te comment, this NPRM referenced material must be released with sufficient time remaining in the NPRM comment period.

Further, this NPRM is being put out for comment near the end of the FAA’s fiscal year, at a time when t he agency is publishing many other items which impact the same regulated entities. Because of this end o f year rush to publish policy, guidance and regulator y proposals, the industry resources for review have been unreasonably strained.

As a result of the issues briefed above, AIA and GA MA request the comment period for NPRM 10-10 be extended for 60-days after all guidance referenced in the proposed rule has been published for public

review and comment.

Sincerely,

_________________________ ______________ _____________ Todd Sigler Gregory J. Bowles Assistant Vice President, Civil Aviation Director , Engineering & Manufacturing Aerospace Industries Association General Aviation Manufacturers Association