14 CFR Part 39
Airworthiness Directives
What an AD is, the legal effect of one, and how to comply another way. The 6 sections below are the ones owners, schools and pilots look up most, each explained in plain English beside the official text.
- 39.3What an Airworthiness Directive isAn Airworthiness Directive is a legally enforceable FAA rule, not a recommendation. ADs apply to four kinds of product: aircraft, aircraft engines, propellers and appliances.
- 39.7Flying without complying with an ADAnyone who operates a product that does not meet the requirements of an applicable Airworthiness Directive is in violation of 39.7. That makes an overdue AD a reason not to fly, and the pilot and the owner can both be held responsible.
- 39.11What an AD can requireAn AD can require three kinds of thing: inspections you must carry out, conditions and limitations you must comply with, and actions you must take to resolve the unsafe condition.
- 39.15ADs on a modified aircraft or partYes, an AD still applies after the product has been changed. Modifying, altering or repairing the affected area does not take an aircraft or part out of an AD that names it.
- 39.19Alternative methods of compliance (AMOC)Anyone may propose an alternative method of compliance (AMOC), or a change in compliance time, that gives an acceptable level of safety. You may use it only after the manager of the FAA office named in the AD approves it.
- 39.23Ferrying an aircraft with an open ADYou can usually fly an aircraft with an open AD to a place where the work can be done, but you need a special flight permit (a ferry permit) from the FAA unless your operations specifications already allow it. The AD itself can rule the flight out.
The rest of Part 39 is on the eCFR.