69-23-04 DOWTY ROTOL: Amdt. 39-872. Applies to the following Dowty Rotol propellers with propeller cylinder P/N's RA 44133/1 or RA 44709 or RA 62807 or RA 67888, except propeller cylinders modified by Modification No. (c) VP.2422: (c) R.130/4-20 - 4/12E installed on Vickers Viscount Model 745D aircraft; (c) R.148/4-20 - 4/21E on Viscount Model 744 aircraft; (c) R.186/4-30 - 4/16 on Hawker Siddeley Argosy AW-650 aircraft; and (c) R.175/4-30 - 4/13E on Fairchild F.27 and F.27B aircraft.
Compliance is required as indicated, unless already accomplished.
To prevent failure of propeller cylinders, at the next scheduled propeller overhaul after the effective date of this AD, or before the cylinder accumulates 6,000 hours total time in service, whichever occurs later, incorporate Dowty Rotol Modification No. (c) VP.2480 in accordance with Dowty Rotol Service Bulletin No. 61-564, Revision 4, dated December, 1968, or later ARB- approved issue, or FAA-approved equivalent.
Thisamendment becomes effective December 11, 1969.