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Airworthiness Directive 97-19-10

recurring
Official AD 97-19-10 · FR doc 97-24194 · 1997-09-12 · airframe

Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S- 64E Helicopters

What this AD requires

This amendment supersedes an existing airworthiness directive (AD), applicable to Sikorsky Aircraft-manufactured Model S-64E and S- 64F helicopters, that currently requires initial and repetitive inspections of the main gearbox assembly second stage lower planetary plate (plate) for cracks, and removal and replacement of the plate if cracks are found; and daily inspections of certain main transmission oil filter packs for magnesium chips, and removal and replacement of the main transmission if chips are found. The AD also provides for reworking and re-identifying the plate, as well as establishes a retirement life for the plate, including those that have been reworked and re-identified. This amendment requires, for Model S-64E helicopters, inspections and rework of the plate and establishes a new retirement life for the plate. This amendment is prompted by the type certificate holder's reports that four plates were discovered to have cracks, three of which had been reworked in accordance with the existing AD. The actions specified by this AD are intended to add another plate to the applicability of the AD, remove the requirements of AD 77-20-01 for the Model S-64F and prevent failure of the plate on the Model S-64E due to fatigue cracking, which could lead to failure of the main gearbox and subsequent loss of control of the helicopter.

Repetitive inspection. Re-inspect every 70 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 97-19-10 applies to

MakesErickson Air-Crane Co.
Part-conditional — 6435-20229-102, 6435-20229-102-TS-107, 6435-20229-104.

Main gearbox second stage planetary plate P/N 6435-20229-102/-104 inspection/rework/replacement per Erickson Air-Crane Service Bulletin 64B35-7C (Nov 8, 1995); retirement life established at 2,600 hours TIS. Specific model not confirmed in extracted text.

Whether AD 97-19-10 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 97-19-10 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.