Airworthiness Directive 98-16-16
one-timeAirworthiness Directives; Pilatus Aircraft Ltd. Model PC-7 Airplanes
What this AD requires
This amendment adopts a new airworthiness directive (AD) that applies to certain Pilatus Aircraft Ltd. Model PC-7 airplanes. This AD requires replacing the seal unit on both main landing gear (MLG) legs and the nose landing gear (NLG) leg. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by this AD are intended to prevent MLG or NLG failure caused by deterioration of a MLG or NLG leg seal unit, which could result in damage to the airplane or airplane control problems during takeoff, landing, or taxi operations.
Which aircraft AD 98-16-16 applies to
Requires replacement of main landing gear (MLG) and nose landing gear (NLG) leg seal units per Pilatus SB No. 32-018, dated March 6, 1998, to prevent MLG/NLG leg failure from seal deterioration. Specific Pilatus model not identifiable from the available text (SB number is ATA-chapter based, not model-coded; applicability list truncated).
Whether AD 98-16-16 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.