Is AD 99-25766 a recurring Airworthiness Directive?

No — AD 99-25766 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 99-25766 apply to?

AD 99-25766 applies to Mcdonnell Douglas — models C-9, DC-9-80, MD-88. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 99-25766

one-time

AD 99-25766 · 1999-10-07 · airframe

Airworthiness Directives; McDonnell Douglas Model DC-9, DC-9-80, and C-9 (Military) Series Airplanes, and Model MD-88 Airplanes

What this AD requires

This amendment supersedes two existing airworthiness directives (AD), applicable to certain McDonnell Douglas Model DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 airplanes, that currently require installation of hydraulic line restrictors in the main landing gear (MLG), and modification or replacement of the left and right MLG hydraulic damper assemblies. This amendment requires an additional modification of the MLG hydraulic damper assemblies, or replacement of the MLG hydraulic damper assemblies with modified and reidentified hydraulic damper assemblies. This amendment is prompted by reports indicating that MLG hydraulic damper assemblies removed for overhaul had failed or damaged spring retainers, due to insufficient material thickness of the spring retainers. The actions specified by this AD are intended to prevent failure of the hydraulic damper assemblies of the MLG, which could result in vibration damage and collapse of the MLG.

Which aircraft AD 99-25766 applies to

MakesMcdonnell Douglas

ModelsC-9, DC-9-80, MD-88

certain

Whether AD 99-25766 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:

Method of compliance — The specific action taken (inspected, replaced, modified) and to what revision.

Date — When the work was done.

Aircraft time — Total time in service / tach at compliance — how recurring next-due is computed.

Signature & certificate — The A&P/IA who returned it to service, with certificate number.

Is AD 99-25766 complied with on your aircraft?

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.