What is an Alternative Method of Compliance (AMOC) for an Airworthiness Directive (AD)?
Different approaches or techniques that are not specified in an AD can, after FAA approval, be used to correct an unsafe condition on an aircraft or aircraft product. Although the alternative may not have been known at the time the AD was issued, an alternative method could be acceptable to accomplish the intent of the AD. A compliance time that differs from the requirements of the AD can also be approved if the revised time period provides an acceptable level of safety that is at least equivalent to that of the requirements of the AD.
Why have provisions for approval of an AMOC in an AD?
Provisions for an alternative method are desirable from an aircraft operator’s point of view and also eliminate the need for constant AD revisions when acceptable methods are developed for AD compliance. If an AD does not contain provisions for approving an AMOC, the AD must be revised before compliance can be accomplished by any method other than what is stated in the AD.
Who has the authority to approve an AMOC?
Each AD will state which office within the FAA Aircraft Certification Service is responsible for that AD. The manager of the responsible office has the authority to approve an AMOC, including different compliance times, for the requirements of the specific AD. One of the FAA Aircraft Certification Offices will have responsibility for AMOC approvals for a product manufactured in the United States. For a product manufactured outside the United States, a Standards Staff branch office of one of the four FAA Aircraft Certification Directorates will generally be listed in the AD as having responsibility for AMOC approvals.