| AD Number | 68-20-07 | Status | Active |
| Effective Date | October 08, 1968 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-664 |
| Product Type | ["Propeller"] | Product Subtype | Not specified |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Dowty Propellers |
| Model(s) | (c) R184/4-30-4/ (c) R193/4-30-4/ (c) R257/4-30-4/ |
68-20-07 DOWTY ROTOL: Amendment 39-664. Applies to Dowty Rotol Propellers (c) R.193/4-30-4/50 installed on Fairchild F. 27A-F-G-J, FH.227 and Fokker F.27 Mk 400, (c) R.257/4-30-4/60 installed on Fairchild FH.227B, FH.227C, FH.227D and FH.227E, and (c) R.184/4-30-4/50 installed on Grumman G-159.
Compliance required as indicated unless already accomplished.
To prevent failure of the propeller hub driving center, P/N RA 57500, accomplish the following:
(a) For all propellers except the (c) R.184/4-30-4/50 propeller, incorporate Dowty Rotol Modification (c) VP.2486, in accordance with Dowty Rotol Service Bulletin No. 61.573B dated June, 1968, or later ARB approved issue, or FAA approved equivalent at the next scheduled overhaul or within the next 4500 hours time in service after the effective date of this AD, whichever occurs first.
(b) For (c) R.184/4-30-4/50 propellers accomplish the following:
(1) For propeller hubs having 2500 or more hours time in service on the effective date of this AD and that have not been modified in accordance with paragraph (5), inspect the hub in accordance with paragraph (3) within the next 50 hours time in service and incorporate the modification specified in paragraph (5) at the next scheduled overhaul or prior to the accumulation of 400 hours time in service after the effective date of this AD, whichever occurs first.
(2) For propeller hubs having less than 2500 hours time in service on the effective date of this AD and that have not been modified in accordance with paragraph (5), inspect the hub in accordance with paragraph (3) prior to the accumulation of 2550 hours time in service and incorporate the modification specified in paragraph (5) within the next 400 hours time in service or prior to the accumulation of 2500 hours time in service, whichever occurs later.
(3) Inspect the rear face of the hub driving center flange with a magnifying glass and by the magnetic particle fluid method in accordance with Dowty Rotol Service Bulletin 61-633 dated June 1968, or later approved ARB issue, or an FAA approved equivalent.
(4) If cracked hub driving centers are detected during any inspection, before further flight replace the propeller hub driving center with a serviceable part of the same part number having no cracks.
(5) Incorporate Dowty Rotol Modification No. (c) VP.2486 in accordance with Dowty Rotol Service Bulletin No. 61-573A dated June 1968, or later ARB approved issue, or an FAA approved equivalent. The inspection specified in paragraph (3) is not required in hubs modified in accordance with this paragraph.
This supersedes Amendment 39-587 (33 F.R. 5866), AD 68-08-05.
This amendment becomes effective October 8, 1968.