This advisory circular (AC) provides applicants guidance for obtaining an airworthiness approval for traffic alert collision avoidance systems (TCAS II). It also provides guidance for certification of a stand-alone Mode S transponder system. This AC includes the TCAS II version 7.0 plus the new version 7.1 and performance standards for the optional functionality of TCAS II hybrid surveillance.

AC 20-151A.pdf

This AC sets forth an acceptable means, but not the only means of showing compliance with the provisions of Title 14 of the Code of Federal Regulations (14 CFR) parts 23, 25, 27, and 29 regarding airworthiness type certification requirements for composite aircraft structures involving fiber reinforced materials, e.g., carbon and glass fiber reinforced plastics. Guidance information is also presented on the closely related design, manufacturing, and maintenance aspects.

The procedures outlined in this AC provide guidance material for composite structures, particularly those that are essential in maintaining the overall flight safety of the aircraft (“critical structure” as defined in Appendix 2), and are considered acceptable to the FAA for showing compliance with certification requirements of civil composite aircraft. This circular is published to aid in the evaluation of certification programs for composite applications and to reflect the current status of composite technology. It is expected that this circular will be modified periodically to reflect the continued evolution of composite technology and the data collected from service experience and expanding applications.

There are factors unique to the specific composite materials and processes used for a given application. For example, the environmental sensitivity, anisotropic properties, and heterogeneous nature of composites can make the determination of structural failure loads, modes, and locations difficult. The reliability of such evaluation depends on repeatable structural details created by scaled manufacturing or repair processes. The extent of testing and/or analysis may differ for a structure depending upon the criticality to flight safety, expected service usage, the material and processes selected, the design margins, the failure criteria, the database and experience with similar structures, and on other factors affecting a particular structure. It is expected that these factors will be considered when interpreting this AC for use on a specific application.

Published on 08/03/2009, FAA Advisory Circular AC 33.17-1 A Engine Fire Protection provides guidance directed to aircraft engine manufacturer’s and modifiers to help demonstrate the fire protection regulatory requirements of 14 CFR 33.17.

07/09/2009, AC 20-163, Displaying Geometric Altitude Relative to Mean Sea Level

 AC 91-76A, Hazard Associated with Sublimation of Solid Carbon Dioxide (Dry Ice) Aboard Aircraft

06/25/2009, AC 33.87-2, Comparative Endurance Test Method to Show Durability for Parts Manufacturer Approval of Turbine Engine and Auxiliary Power Unit Parts

06/11/2009, AC 33-7A, Guidance for 30-Second and 2-Minute One-Engine-Inoperative (OEI) Ratings for Rotorcraft Turbine Engines

06/03/2009, AC 65-25E, William (Bill) O’Brien Aviation Maintenance Technician Awards Program

05/21/2009, AC 150/5300-18B, General Guidance and Specification for Submission of Aeronautical Surveys to NGS: Field Data Collections and Geographic Information System (GIS) Standards

05/19/2009, AC 150/5345-46D, Specifications for Runway and Taxiway Light Fixtures