Is AD 2016-21-05 a recurring Airworthiness Directive?

No — AD 2016-21-05 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2016-21-05 apply to?

AD 2016-21-05 applies to Boeing — models 777-200, 777-200LR, 777-300, 777-300ER, 777. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2016-21-05

one-time

Official AD 2016-21-05 · FR doc 2016-25491 · 2016-11-14 · airframe

Airworthiness Directives; The Boeing Company Airplanes

What this AD requires

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, -200LR, -300, and -300ER series airplanes. This AD was prompted by a report indicating that the manufacturer discovered locations where the control components and wiring of the left and right engine fuel spar valves do not have adequate physical separation to meet the redundant system separation requirements. This AD requires modifying the wiring, and installing a new relay bracket and new location for the relay on the left and right engine fuel spar valves. This AD also requires an inspection to identify the part number of the motor operated valve (MOV) actuators for the left and right engine fuel spar valves; replacement of specified MOV actuators with new MOV actuators; certain bonding resistance measurements; and applicable corrective actions. We are issuing this AD to prevent loss of control of both the left and right engine fuel spar valves during a single event, such as local wire bundle damage or a wire bundle fire, which could cause both engines to shut down or result in the inability to control an engine fire.

Which aircraft AD 2016-21-05 applies to

MakesBoeing

Models777-200, 777-200LR, 777-300, 777-300ER, 777

Applies to airplanes identified in Boeing Special Attention Service Bulletin 777-28-0061, Revision 2, dated May 4, 2015.

Whether AD 2016-21-05 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 2016-21-05 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.