Airworthiness Directive 2021-07-09
recurringAirworthiness Directives; The Boeing Company Airplanes
What this AD requires
The FAA is superseding Airworthiness Directive (AD) 2007-07- 03, which applied to certain The Boeing Company Model 747-100, 747- 100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. AD 2007-07-03 required repetitive tests to detect hot air leaking from the trim air diffuser ducts or sidewall riser duct assemblies (collectively referred to as TADDs), related investigative actions, and corrective actions if necessary. AD 2007-07-03 also provided an optional terminating action for the repetitive tests. This AD requires repetitive inspections of all TADD material for damage and applicable on-condition actions. This AD was prompted by reports that high temperature composite material TADDs installed as specified in AD 2007-07-03 have also failed. The FAA is issuing this AD to address the unsafe condition on these products.
Which aircraft AD 2021-07-09 applies to
Whether AD 2021-07-09 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.