Aircraft Certification Service (AIR) Draft Advisory Circulars (ACs) Open for Comment

Document Title:AC 20-196, Airworthiness Approval of Airborne Collision Avoidance Systems (ACAS)
Summary:

This AC replaces AC 20-151C for installation of Traffic Alert and Collision Avoidance Systems (TCAS) II with hybrid surveillance. It also contains new material for installation of Airborne Collision Avoidance Systems Xa (ACAS Xa) developed under the FAA’s NextGen program. Specifically, it provides acceptable means, but not the only means, for demonstrating compliance with title 14, Code of Federal Regulations (14 CFR) Parts 23 or 25 airworthiness regulations for initial and follow-on installations under the following Technical Standard Orders (TSOs):

  • TSO-C119c, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS II with Optional Hybrid Surveillance,
  • TSO-C119d, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS II With Hybrid Surveillance,
  • TSO C119e, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS II with Hybrid Surveillance, and
  • TSO-C219a, Airborne Collision Avoidance System (ACAS) Xa/Xo.
Documents for Download:                         Draft Document
Comment Matrix
Comments Due:November 19, 2026
How to Comment:Email Comments to: 9-AVS-TechWriters@faa.gov
Document Title:AC 21-56, Compliance Assurance System (CAS) Requirements for a Technical Standard Order Authorization (TSOA) Applicant/Holder
Summary:This advisory circular (AC) provides guidance on an acceptable means, but not the only means, for an applicant or holder (hereafter referred to as “applicant”) of a Technical Standard Order Authorization (TSOA) to implement a Compliance Assurance System (CAS) within their organization. A TSOA applicant with an established CAS would be using a systems-based approach as the basis for determining design compliance to the requirements of a Technical Standard Order (TSO). This AC defines the baseline organizational capabilities and engineering processes that constitute an effective CAS. Applicants may use these criteria to evaluate, establish, or improve their internal compliance architectures.
Documents for Download:                         Draft Document
Comment Matrix
Comments Due:December 8, 2026
How to Comment:Email Comments to: 9-AVS-TechWriters@faa.gov

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Last updated: Friday, October 23, 2026