76-18-03 DOWTY ROTOL: Amendment 39-2711. Applies to Dowty Rotol Type (c)R193/4-30-4/50, (c)R257/4-30-4/60, and (c)R184/4-30-4/50 propellers having Hub Driving Centers, P/N 601026638, modified to Dowty Rotol Mod. No. (c)VP2486. These propellers are installed on, but not necessarily limited to, Fokker Model F-27, Fairchild Model FH-227, and Grumman Model G-159 Series airplanes.
NOTE: Dowty Rotol Mod. No. (c)VP2486 is covered in Dowty Rotol Service Bulletin 61-573A, dated June 1968, and the incorporation of the modification is required by AD 68-20-7.
Compliance is required at the next propeller overhaul or within the next 4700 hours propeller time in service after the effective date of this AD, whichever occurs first, unless already accomplished.
To prevent cracking and possible failure of the hub driving center due to improper machining, accomplish the following:
(a) For propellers that incorporate hub and driving center assemblies having the following serial numbers, rework the hub driving center to salvage scheme No. 640144000, in accordance with Dowty Rotol Service Bulletin 61-858, dated February 4, 1975, or an equivalent approved in accordance with paragraph (c) of this AD:
Hub and Driving Center Assembly Serial Numbers
Serial No.
Propeller Type
Serial No.
Propeller Type
184/59/47
R184/4-30-4/50
DRG/31/62
R184/4-30-4/50
184/59/60
"
DRG/288/64
"
184/59/62
"
DRG/290/64
"
184/59/64
"
DRG/56/65
"
184/59/65
"
DRG/116/65
"
184/60/79
"
DRG/122/65
"
184/60/86
"
DRG/223/65
"
184/60/89
"
DRG/223/65
"
184/60/94
"
DRG/224/65
"
184/60/95
"
DRG/42/66
"
184/60/96
"
DRG/122/66
"
184/60/99
"
193/58/11
R193/4-30-4/50
184/60/103
"
193/58/17
"
184/60/126
"
193/58/27
"
184/60/146
"
193/58/38
"
184/60/147
"
193/59/116
"
184/60/159
"
193/59/119
"
184/60/160
"
193/60/150
"
DRG/10/61
"
193/60/151
"
DRG/12/61
"
DRG/32/62
"
DRG/14/61
"
DRG/119/66
"DRG/17/61
"
DRG/442/66
"
DRG/20/61
"
DRG/131/66
R257/4-30-4/60
DRG/24/61
"
DRG/407/66
"
DRG/25/61
"
DRG/408/66
"
DRG/31/61
"
DRG/454/66
"
DRG/38/61
"
DRG/28/67
"
DRG/41/61
"
DRG/30/67
"
DRG/43/61
"
DRG/86/67
"
DRG/44/61
"
DRG/93/67
"
DRG/48/61
"
DRG/95/67
"
DRG/49/61
"
DRG/189/67
"
DRG/58/61
"
DRG/194/67
"
DRG/2/62
"
DRG/231/67
"
DRG/9/62
"
DRG/233/67
"
DRG/10/62
"
DRG/344/67
"
DRG/11/62
"
DRG/345/67
"
DRG/19/62
"
DRG/348/67
"
(b) For propellers that incorporate hub and driving center assemblies having serial numbers not listed in paragraph (a) of this AD, accomplish the following in accordance with Dowty Rotol Service Bulletin 61-858, dated February 4, 1975, or an equivalent approved in accordance with paragraph (c) of this AD:
(1) Inspect the hub driving center to verify correct machining.
(2) If the hub driving center is found to be incorrectly machined, rework the hub driving center tosalvage scheme No. 640144000.
(c) The equivalent means of compliance specified in paragraphs (a) and (b) of this AD must be approved by the Chief, Aircraft Certification Staff, FAA Europe, Africa and Middle East Region, c/o American Embassy, APO New York, N.Y. 09667.
This amendment becomes effective on October 1, 1976.