AD 78-09-03 ACTIVE

78-09-03 DOWTY ROTOL, LTD.: Amendment 39-3196. Applies to Dowty Rotol Type R193/4-30-4/50 and R193/4-30-4/61 propellers of the following serial numbers which may be installed on, but not necessarily limited to, Fairchild Model F27A, F27F, F27J, FH-227, and FH- 227-1; and Fokker F-27 Mks. 200, 400, 500 and 600 airplanes:

193/60/167
DRG/34/61
DRG/66/62
DRG/284/63
DRG/120/64
DRG/4/61
DRG/35/61
DRG/19/63
DRG/285/63
DRG/121/64
DRG/5/61
DRG/2/62
DRG/22/63
DRG/286/63
DRG/122/64
DRG/6/61
DRG/3/62
DRG/24/63
DRG/287/63
DRG/123/64
DRG/7/61
DRG/33/62
DRG/25/63
DRG/320/63
DRG/138/64
DRG/9/61
DRG/35/62
DRG/26/63
DRG/321/63
DRG/141/64
DRG/13/61
DRG/36/62
DRG/72/63
DRG/337/63
DRG/142/64
DRG/14/61
DRG/37/62
DRG/134/63
DRG/14/64
DRG/158/64
DRG/25/61
DRG/41/62
DRG/136/63
DRG/17/64
DRG/207/64
DRG/26/61
DRG/42/62
DRG/222/63
DRG/36/64
DRG/208/64
DRG/27/61
DRG/49/62
DRG/224/63
DRG/78/64
DRG/292/66
DRG/33/61
DRG/50/62
DRG/226/63
DRG/79/64
DRG/296/66

Compliance is required as indicated, unless already accomplished.

To reduce the possibility of propeller hub and driving center assembly failure due to corrosion, and subsequent possible propeller failure, accomplish the following:

(a) Within the next 1000 hours time in service after the effective date of this AD, or at the next scheduled propeller overhaul, whichever occurs first, inspect the propeller hub and driving center assembly in accordance with Dowty Rotol Service Bulletin 61-882, dated March 11, 1977 (hereinafter SB 61-882), and the therein referenced Dowty Rotol Propeller Overhaul Manual Pub. No. 61-2-2, Repair Scheme Manual Pub. No. 923; and Process Specification Manual Pub. No. 872, or FAA-approved equivalents.

(b) If, as a result of the inspection required by paragraph (a) of this AD, propeller hub or driving center assembly corrosion is found to exceed the limits specified in Dowty Rotol Overhaul Manual 61-2-2 and Repair Scheme Manual Publication No. 923 Repair Schemes 650013110 and 650013120 or an FAA-approved equivalent, before further operation, replace the propeller hub and driving center assembly with a serviceable propeller hub and driving center assembly or an FAA-approved equivalent.

(c) The equivalent means of compliance specified in paragraphs (a) and (b) of this AD must be approved by the Chief, Aircraft Certification Staff, AEU-100, Europe, Africa, and Middle East Region, Federal Aviation Administration, c/o American Embassy, Brussels Belgium.

This amendment becomes effective May 22, 1978.