An Airworthiness Directive (AD) is a legally enforceable rule the FAA issues when it finds an unsafe condition in an aircraft, engine, propeller or appliance that's likely to exist in others of the same design. ADs are issued under 14 CFR Part 39. If an AD applies to your aircraft and you haven't complied, the aircraft isn't airworthy.

As the owner, keeping track of ADs is your responsibility, even though your mechanic does the work.

Who's responsible

Under §91.403(a), the owner or operator is primarily responsible for maintaining the aircraft in an airworthy condition, including compliance with ADs. Your mechanic researches ADs at the annual inspection and records compliance, but if a recurring AD comes due between annuals, it's on you to notice.

The kinds of AD you'll see

  • One-time ADs: do an inspection, replace a part or modify something once, and you're done. Record the compliance and it stays complied.
  • Recurring ADs: repeat an inspection at an interval, by hours, by calendar time, or by cycles (whichever comes first, in some cases). These are the ones that catch owners out.
  • Terminating action: some recurring ADs offer a permanent fix (for example, replacing the part with an improved one) that ends the repeat inspections.
  • Emergency ADs: issued for urgent safety problems and effective immediately for those who receive them.

ADs can apply to the airframe, the engine, the propeller, or an appliance (a magneto, a vacuum pump, an ELT, a fuel valve). An airplane's applicable ADs depend on its exact model and serial number and those of every component installed, which is why the list changes when you swap an engine, prop or accessory.

Alternative method of compliance (AMOC)

Sometimes the AD's prescribed method doesn't fit. An owner or mechanic can apply to the FAA for an alternative method of compliance. An approved AMOC is documented and recorded like the AD itself.

What your records must show

§91.417(a)(2)(v) requires the owner to keep records of the current status of applicable ADs, including for each:

  • the AD number and revision date,
  • the method of compliance, and
  • if the AD involves recurring action, the time and date when the next action is required.

This record is usually an AD compliance list kept with the logbooks: every AD that applies, with how and when it was complied with, and when it's next due. A list that only says "all ADs complied with" doesn't show the next due time for recurring ADs.

Finding the ADs that apply to your aircraft

  • The FAA publishes ADs in the Dynamic Regulatory System (DRS), searchable by make and model.
  • Search for the airframe, engine and propeller models, and for appliances installed (magnetos, carburetors, vacuum pumps, ELTs, seat rails and so on).
  • Your mechanic will typically run an AD search at each annual; ask for a printout and keep it with your records.
  • New ADs are issued all the time. Many owners subscribe to email notifications for their models.

Keeping recurring ADs from slipping

Recurring ADs fail when nobody is watching the clock between annuals. A few habits help:

  1. Put every recurring AD on the same list as your other due items (oil changes, transponder check, ELT battery), with both the hours and the date it's due.
  2. Record tach time at the end of every flight, so hour-based items are always current.
  3. Look ahead: review what's coming due in the next 30 days or 10 hours, especially before a long trip.
  4. Ground the airplane yourself if a recurring AD is overdue. Flying with an overdue AD makes the airplane unairworthy and can affect your insurance.

Frequently asked questions

What is an Airworthiness Directive?

A legally enforceable FAA rule, issued under 14 CFR Part 39, that requires action to correct an unsafe condition in an aircraft, engine, propeller or appliance. Compliance is mandatory for the aircraft it applies to.

Who is responsible for AD compliance, the owner or the mechanic?

The owner or operator is primarily responsible under 14 CFR 91.403. The mechanic performs and records the work, but the owner must make sure ADs, including recurring ones, are complied with on time.

What must an AD compliance record include?

Under 14 CFR 91.417, the current status of each applicable AD: the AD number and revision date, the method of compliance, and for recurring ADs, the time and date the next action is due.

Can I fly with an overdue AD?

No. An aircraft that hasn't complied with an applicable AD is not airworthy. In limited cases a special flight permit can be issued to fly it to a place where the work can be done.