This advisory circular (AC) is a summary of the current available data regarding identification and treatment of corrosive attack on aircraft structures and engine materials. Corrosion inspection frequency, corrosion identification, and the Federal Aviation Administration (FAA) emphasize here that corrosion treatment continues to be the responsibility of you, the operator, and you should accomplish these inspections per this AC, the manufacturer’s recommendations, or your own maintenance program. The information in this AC is applicable to aircraft for which the manufacturer has not published corrosion control information.

This order prescribes Federal Aviation Administration (FAA) procedures and responsibilities for
aircraft accident and incident notification, investigation, and reporting. It also provides a description
ofthe organization, functions, and authorities ofthe Accident Investigation Division, AVP-100. This
order also provides direction and guidance to aviation safety inspectors and air safety investigators
when they are called upon to act as, or support, the FAA Investigator-in-Charge (IIC) during an
accident or incident investigation. It also explains the roles and responsibilities ofthe FAA and the
National Transportation Safety Board (NTSB) when conducting investigations. All concerned
personnel must familiarize themselves with the provisions ofthis order that pertain to their operational
responsibilities and exercise their best judgment ifthey encounter situations not covered by the order.

This memorandum allows Aircraft Certification Service (AIR) personnel to be newly
assigned as an OMT lead or core OMT member without prior completion of FAA
course 28463, Basic Compliance Auditing for AVS Personnel. Personnel being assigned
as an OMT lead or core OMT member who are required to complete the course must do
so prior to or within 4 months after assignment if multiple course offerings are available
within the 4 month period. If multiple offerings are not available during the first 4 month
period after assignment, core OMT members must attend a course offering within the
next 4 month period.

This advisory circular (AC) provides guidance for the flight test evaluation of transport category
airplanes. This AC includes flight test methods and procedures to show compliance with the
regulations contained in title 14, Code of Federal Regulations (14 CFR) part 25, subpart B,
“Flight,” which address airplane performance and handling characteristics.
This revision, AC 25-7D, clarifies paragraph 23.2.4, Engine Restart Capability—§ 25.903(e);
adds paragraph 34.4, Circuit Protective Devices—§ 25.1357; and revises appendix B, Function
and Reliability (F&R) Tests, of this AC. This AC has been re-formatted to use a new paragraph
numbering system for improved usability.
The first change revises the means of compliance associated with demonstrating the restart
capability required by § 25.903(e). The second change adds a paragraph providing guidance for
flight test evaluation of compliance with the requirements for circuit protective devices. It is
made in response to recommendations from the National Transportation Safety Board. The third
change revises appendix B concerning F&R testing. It addresses issues that arose with F&R
testing on recent certification programs where the current guidance was unclear.