AD 83-07-06

83-07-06 BOEING VERTOL COMPANY AND KAWASAKI HEAVY INDUSTRIES, LTD.: Amendment 39-4600. Applies to Boeing Vertol Model 107-II and Kawasaki Model KV107-II and KV107-IIA helicopters certificated in all categories equipped with No. 5 Synchronizing Shaft, P/N 107D3340-1 or 107D3140-1. Compliance is required as indicated on all No. 5 Synchronizing Shaft Assemblies P/N 107D3340-1 or 107D3140-1 with 1200 hours' or more total time in service.

To prevent failure of the steel synchronizing shaft due to improperly drilled rivet holes, accomplish the following:

A. Within 50 hours' time in service after the effective date of this AD (unless already accomplished within the past 250 hours' time in service) and every 300 hours' time in service thereafter, visually inspect the interior and exterior surfaces of the No. 5 Synchronizing Shaft Assembly P/N 107D3340-1 or 107D3140-1 for cracks, damage or defects in the area adjacent to the adapter-to-tube rivets at both ends, particularly at the inboard row of rivets. The visual inspection shall be either a lighted borescope inspection using at least 2X magnification or dye penetrant inspection methods combined with at least 2X visual magnification.

All paint on surfaces to be inspected must be removed prior to inspection.

B. Before the accumulation of 2000 hours' time in service, or before the accumulation of 2000 hours' time in service since last magnetic particle inspection, whichever is less, and at each 2000-hour interval thereafter, magnetic particle inspect the entire shaft assembly, P/N 107D3340-1 or 107D3140-1 in accordance with Boeing Vertol Overhaul Manual 107-5.

C. Replace any cracked or otherwise unserviceable part found during the inspections of Paragraphs A or B with serviceable parts prior to further flight.

D. An equivalent method of compliance with this AD may be used when approved by the Manager, New York Aircraft Certification Office, New England Region.

This amendment becomeseffective April 4, 1983.