Is AD 98-3634 a recurring Airworthiness Directive?

No — AD 98-3634 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 98-3634 apply to?

AD 98-3634 applies to Pilatus Britten-Norman — models BN-2. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 98-3634

one-time

AD 98-3634 · 1998-02-17 · appliance

Airworthiness Directives; Pilatus Britten-Norman Ltd. BN-2, BN- 2A, and BN-2B Series Airplanes

What this AD requires

This amendment supersedes Airworthiness Directive (AD) 97-03- 03, which applies to certain Pilatus Britten-Norman Ltd. (Pilatus) BN- 2, BN-2A, and BN-2B series airplanes that do not have Modification NB/ M/1571 generator terminal diodes installed. AD 97-03-03 currently requires the installation of higher capacity diodes on the generator switches regardless of whether the airplane is equipped with the original 50 amp DC generating system or a Modification NB/M/1148, which is a 70 amp system. This action retains the actions of AD 97-03-03, but modifies the applicability section to reflect that this AD does not apply to Pilatus BN-2, BN-2A, and BN-2B series airplanes with 50 amp DC generation systems installed. This AD is the result of reports that the applicability section of AD 97-03-03 is incorrect. The actions specified by this AD are intended to prevent a loss of electrical power to the navigation, communications, and lighting systems, which could impair the pilot's ability to maintain control of the airplane.

Which aircraft AD 98-3634 applies to

MakesPilatus Britten-Norman

ModelsBN-2

Applies per Pilatus Britten-Norman Aircraft Manufacturers Service Bulletin BN-2/SB.228, Issue 2, dated January 17, 1996 (supersedes AD 97-03-03); requires replacing diodes (old P/N 340502014 type 10B1/10D1, new P/N NB-81-5873 type 60S6) on the STBD GEN and PORT GEN switches. Text does not give a more specific model designation (e.g., BN-2A/BN-2B) than the BN-2 family.

Whether AD 98-3634 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.

Supersession

Supersedes AD 97-03-03.

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 98-3634 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.