Alternative Methods of Compliance: Request, Review, and Approval

An FAA Alternative Method of Compliance approval process begins when an aircraft owner, operator, design approval holder, or parts manufacturer sends the FAA a written proposal — with supporting engineering data — showing that a different way of addressing an Airworthiness Directive (AD) will deliver an equivalent level of safety. Authority for the request sits in 14 CFR 39.19, and the alternative cannot be used until the responsible FAA office manager, or an authorized designee, issues a formal approval.¹ Everything else in the process — where to file, what to include, how long it takes, what happens if you’re denied — flows from that basic structure.

When You Actually Need an AMOC

An AD issued under 14 CFR Part 39 is a binding rule. It tells you exactly what to inspect, repair, or modify, and by when. Operating a product that doesn’t meet an applicable AD violates 14 CFR 39.7 every time you fly.² Until you either finish the required work or hold an approved alternative, the aircraft is grounded as a matter of law.

The most common reason to seek an AMOC is that something about your specific aircraft blocks the standard fix. Under 14 CFR 39.17, if a modification, alteration, or repair affects your ability to accomplish what the AD requires, you must request FAA approval of an alternative — unless you can demonstrate the change already eliminated the unsafe condition.³

Operators also file AMOC requests when they’ve developed a more efficient way to address the unsafe condition, when they need more time to comply, when a required part is no longer available, or when errors in the AD or its referenced service documents make literal compliance impossible.⁴ The theme in every case is the same: the standard path is blocked or impractical, but the safety concern the AD was written to address still has to be resolved.

What to Put in the Request

Incomplete submissions are the most common reason for delays. A strong package gives the reviewing engineer everything needed to make a safety determination without follow-up requests. Include:

The exact AD number and the specific paragraphs you want an alternative for.
Aircraft, engine, or propeller make, model, and serial numbers covered by the request.
A clear description of your proposed method and why the AD’s prescribed action doesn’t work for your situation.
Engineering substantiation — analyses, calculations, test results, structural reports, material specifications, or other technical data — showing the alternative provides an equivalent level of safety.
The duration and scope you’re asking for: permanent, a defined number of flight hours, or a temporary measure until standard compliance can be completed.

The evaluator will compare your submission directly against the risk analysis that justified the original AD, so the data has to address the same failure modes the AD was written to catch.⁵ If a fastener is unavailable, include shear strength calculations for the substitute. If an existing modification blocks access to an inspection area, propose a different inspection technique and show the data confirming it detects the same failure modes.

Previous AMOC approvals for similar situations, or related findings from the same AD, can strengthen your case. Include them if you have them. Everything you submit becomes part of the permanent project file for that AD.⁵

One structural decision to think about before filing: whether you want an individual AMOC or a global one. A global AMOC covers two or more operators and is automatically transferable when an aircraft changes hands. An individual AMOC is approved for a single operator, and it transfers only if the FAA determines it doesn’t rely on factors unique to you — your maintenance schedule, your facilities and tooling, your training program, or recurring inspections built around your own program.⁵

Where to Send the Request and Who Reviews It

Routing depends on who you are. Individual owners and small operators send proposals through their assigned Principal Inspector at the local Flight Standards District Office. The PI may add comments before forwarding the package to the manager of the office identified in the AD, typically an Aircraft Certification Office. You can send a copy directly to that manager at the same time, but the PI routing is required.⁶

Design approval holders and others without an assigned PI send proposals directly to the manager of the FAA office identified in the AD.⁵ Getting the routing wrong means the request sits in a queue nobody is watching.

Some AMOC requests never reach an FAA engineer at all. The agency authorizes company Designated Engineering Representatives (DERs) and Organization Designation Authorization (ODA) holders to approve certain categories of AMOC directly, with no further FAA sign-off. The AD itself usually states whether delegated authority applies.⁷ Delegation is limited to cases where the requester intends to restore the product to its type certification basis or another known, published standard, and it covers structural repairs and modifications, temporary structural repairs, alternative inspection methods when a repair makes the AD-mandated inspection impossible, and minor non-structural deviations that don’t affect the corrective action addressing the unsafe condition. DERs operating under delegated authority don’t have to coordinate with the local Flight Standards office, but they must still decide whether the AMOC should be transferable, and the FAA can revoke delegated authority at any time.

How Long It Takes and What Approval Looks Like

Processing time varies. Straightforward requests can be turned around in a few weeks; technically complex proposals involving structural modifications or novel inspection methods can take several months and often require coordination between the certification office and multiple safety specialists.⁵ No FAA-wide standard timeline is published.

If the proposal is acceptable, the responsible office manager (or a person with delegated authority) issues a formal approval, either by email or letter. The approval document identifies the AD number and paragraphs covered, the make and model designations or serial numbers it applies to, and any conditions or limitations you must follow.⁵ Receiving an acknowledgment of your submission or a tracking number is not approval. Until the approval document is in hand, the alternative cannot be used.

Urgent After-Hours Requests

FAA Order 8110.103B includes a 24/7 support process for AMOCs that come up outside business hours. To qualify, the need must arise after normal business hours and support must be necessary to avoid significant air transportation disruptions or substantial operator impact.⁵ The operator’s PI or Flight Standards office identifies the need and notifies the Airworthiness Engineering Group, which contacts the manager of the responsible certification office. That manager decides whether the criteria are met, whether staff is available, and whether the data supports approval. If only limited operation can be justified, the FAA may approve a time-limited AMOC while a permanent solution is worked out.

The FAA is explicit that this channel is not intended for operators who failed to plan adequately for AD compliance.⁵

If the FAA Denies Your Request

Order 8110.103B has no formal appeal process for a denial. It does instruct evaluators to give the requester a chance to fix deficiencies before a final denial is issued, so if your submission falls short you should hear about the specific problems and get an opportunity to supply additional data or a revised proposal.⁵

If the denial becomes final, the written response states the reasons. Your options at that point are to comply with the AD as written, file a new AMOC proposal that addresses the FAA’s identified safety concerns, or pursue the issue through the FAA’s broader petition and review processes. The aircraft stays grounded in the meantime.

After Approval: Records, Transfer, and Revocation

An approved AMOC creates ongoing obligations. Under 14 CFR 91.417, the aircraft’s maintenance records must show the current status of all applicable ADs, including the method of compliance, the AD number, and revision date, plus when the next action is due for anything recurring. The AMOC approval document is the proof that your alternative is the legally valid method, and it must be retained and transferred with the aircraft on sale.⁸

During inspections or ramp checks, the technician references the AMOC to explain why the aircraft doesn’t show standard AD compliance. If you can’t produce it, the inspector has no way to verify that your deviation is authorized, and the aircraft may be found unairworthy. Any flight-hour limits, calendar deadlines, or recurring inspection requirements written into the approval have to be tracked precisely. Operating outside the scope of what the AMOC authorizes is treated the same as violating the AD.

Approval isn’t permanent either. If the FAA later determines the AMOC no longer provides an acceptable level of safety, it must revoke the approval. The responsible office sends a certified letter proposing revocation and stating reasons; the holder gets at least seven days to respond with data challenging the determination or a different AMOC that addresses the new concerns. A final revocation letter follows within five business days of the notice period closing. In a genuine emergency, the FAA can skip the notice period and revoke immediately, which effectively grounds the aircraft until either the AD is complied with or a new AMOC is approved.⁵

The Cost of Skipping the Process

Flying an aircraft that doesn’t meet an applicable AD — whether you never complied, your AMOC was revoked, or you operated outside the scope of your approval — violates 14 CFR 39.7 each time you fly, with a separate violation for each day the condition continues or for each flight.²

Under the inflation-adjusted penalty schedule, the maximum civil penalty per violation is up to $17,062 for individuals and small businesses that are not airmen; up to $1,875 for airmen serving as airmen and individual operators; and up to $75,000 for companies and other entities. Those figures reflect the most recent inflation adjustment effective as of late 2024.⁹ Because each flight counts separately, exposure adds up quickly.

Beyond civil penalties, the FAA has authority under 49 U.S.C. § 44709 to amend, suspend, or revoke any certificate — including airman certificates and aircraft airworthiness certificates — when the Administrator determines safety in air commerce requires it.¹⁰ A pattern of AD violations is exactly the kind of concern that triggers certificate action. The practical rule is straightforward: don’t fly until either the AD is complete or the AMOC is approved in writing.

1
eCFR. 14 CFR 39.19 – May I Address the Unsafe Condition in a Way Other Than That Set Out in the Airworthiness Directive?
2
eCFR. 14 CFR Part 39 – Airworthiness Directives
3
eCFR. 14 CFR 39.17 – What Must I Do if a Change in a Product Affects My Ability to Accomplish the Actions Required in an Airworthiness Directive?
4
Federal Aviation Administration. Recommendations Report – Section 222 Subgroup
5
Federal Aviation Administration. FAA Order 8110.103B – Alternative Methods of Compliance
6
eCFR. 14 CFR 39.19 – May I Address the Unsafe Condition in a Way Other Than That Set Out in the Airworthiness Directive?
7
Federal Aviation Administration. FAA Order 8110.103B – Alternative Methods of Compliance
8
eCFR. 14 CFR 91.417 – Maintenance Records
9
eCFR. 14 CFR Part 13 Subpart H – Civil Monetary Penalty Inflation Adjustment
10
Office of the Law Revision Counsel. 49 USC 44709 – Amendments of Certificates and Ratings