Is AD 98-04-12 a recurring Airworthiness Directive?

Yes — AD 98-04-12 requires a repetitive inspection every 20 hours. Next-due depends on the aircraft's time in service.

Which aircraft does AD 98-04-12 apply to?

AD 98-04-12 applies to Robinson Helicopter Company — models R44. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 98-04-12

recurring

Official AD 98-04-12 · FR doc 98-9478 · 1998-04-10 · airframe

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

What this AD requires

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 98-04-12 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (RHC) Model R44 helicopters by individual letters. This AD requires an initial and repetitive measurement of the lateral cyclic trim spring shaft (shaft) diameter and replacement of the shaft spring assembly (spring assembly) if the shaft diameter is excessively worn. Replacement of the spring assembly with a modified spring assembly is considered terminating action for this AD. This amendment is prompted by an incident in which a pilot felt binding in the cyclic control when attempting to move it to the left. A precautionary landing was made using only right-hand turns. Subsequent inspection revealed that a notch was worn in the shaft, which caused the shaft and spring to move from the lower mount and interfere with the lateral control. Inspection of a second RHC Model 44 helicopter revealed similar wear. Excessive wear can create a notch on the shaft, which can cause the spring assembly to move out of its lower mount. This condition, if not corrected, could lead to the shaft interfering with lateral cyclic control, which could result in loss of control of the helicopter.

Repetitive inspection. Re-inspect every 20 hours. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 98-04-12 applies to

MakesRobinson Helicopter Company

ModelsR44

Serial-conditional — narrows to serials 0002–0420, 0425–0425, 0426–0426, 0427–0427.

Part-conditional — C056-1.

Applies only to R44 helicopters with C056-1 Rev. A through G lateral cyclic trim spring assembly installed (superseded by Rev. H spring assembly).

Whether AD 98-04-12 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 98-04-12 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.