Definition
A free FAA publication issued every two weeks that lists all newly issued and recently amended Airworthiness Directives (ADs). It serves as a regular update source so owners, operators, and maintenance personnel can stay current on AD activity affecting their aircraft, engines, propellers, and appliances.
Plain English
A free FAA update that comes out every two weeks listing the latest safety orders that aircraft owners and mechanics must comply with. Reading it regularly is how you find out about new required fixes for your aircraft.
Context Anchor
Seen when checking whether an aircraft, engine, propeller, or installed equipment has any new Airworthiness Directives that must be complied with.
Derivation
‘Biweekly’ comes from Latin ‘bi-’ meaning two, plus ‘weekly,’ so it means ‘every two weeks.’ ‘AD’ stands for Airworthiness Directive. Together it simply names a publication that comes out on a two-week cycle and contains AD information.
Why Pilots Care
Aircraft must comply with every applicable AD to remain legally airworthy; missing a new directive can ground the airplane or create safety risks.
Intuition Check
Do not read “AD Biweekly” as an optional newsletter. In this context, it is a regular FAA listing that points to mandatory safety directives, and “biweekly” means every two weeks.
Example Sentence 1
The owner reviewed the latest AD Biweekly to check whether any new directives applied to his Cessna 172.
Example Sentence 2
Mechanics review each new AD Biweekly to identify any directives that apply to the aircraft they service.