This advisory circular (AC) describes acceptable means for showing compliance with
paragraph (c) of Title 14, Code of Federal Regulations (14 CFR) 25.901, Installation, of
subpart E, Powerplant. Section 25.901(c) is intended to ensure that the applicant conducts an
overall safety assessment of the powerplant and auxiliary power unit (APU) installations that
meets the requirements of § 25.1309, while also addressing the unique compliance concerns
involved in powerplant and APU installations. The regulation is intended to augment other
applicable part 25 design and performance standards for transport category airplanes. This
document describes a method of conducting a system safety assessment (SSA) of the powerplant
installation.

This deviation memorandum updates FAA Order 8000.71 to replace the term and
definition for “hybrid lift” with “powered-lift,” as one of the examples of aircraft
category. The term “powered-lift” is defined in § 1.1 of title 14, Code of Federal
Regulations (CFR) and has not been prohibited from FAA use with regards to the order
which states, in paragraph 5.i. Applicability, “Where definitions are already present in
FAA regulations (for terms such as ‘aircraft,’ ‘type,’ or ‘type certificate’), the regulatory
definitions will take precedent.”
The International Civil Aviation Organization (ICAO) has since adopted the term and
definition of “powered-lift,” which fully aligns with the FAA definition. Therefore, any
usage of the “hybrid lift” term is now outdated for international agreement

This notice provides inspectors with information on the Federal
Aviation Administration (FAA)-approved deicing program for Winter 2024–2025. This notice is
designed to be used in conjunction with the FAA Holdover Times (HOT), Degree-Specific
Holdover Times (DSHOT), Regression Data, and Allowance Time Guidelines for
Winter 2024–2025. This notice replaces Notice N 8900.667, FAA-Approved Deicing Program
for Winter 2023–2024, which expired on July 31, 2024.

This notice provides guidance to aviation safety inspectors (ASI)
authorized to perform field approvals, Flight Standards (FS) Safety Assurance offices using the
Electronic FAA Form 337 (E337) system, and Aviation Safety Engineers (ASE). This notice is
administrative in nature

On September 7, 2023, the Federal Aviation Administration (FAA)
published Notice N 8100.18, Organization Designation Authorization (ODA) Holder
Interference with ODA Unit Members (UM) and Communication between UMs and the FAA, to
provide instructions and procedures intended to eliminate or minimize ODA holder interference
with UMs performing their authorized functions, and to ensure free communication between
UMs and the FAA. This Notice extends the ongoing interference reporting, communication
instructions, and Interference Review Team (IRT) procedures in Notice N 8100.18. The FAA
intends that the policies contained in this Notice will be incorporated into the FAA’s next
revision of FAA Order 8100.15, Organization Designation Authorization Procedures, except that
the ongoing role of the IRT would remain as established by this Notice. To the extent that this
Notice conflicts with the current Order 8100.15B, the contents of this Notice supersede that
Order