AD 68-20-07

final rule

DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers

AD Number
68-20-07
Status
final_rule
Effective Date
Product Category
propeller
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft propeller assembly
Problem area Propeller

Applicability

TypeManufacturerModelDetails
aircraft Dowty Propellers (c) R184/4-30-4/ DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers
aircraft Dowty Propellers (c) R193/4-30-4/ DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers
aircraft Dowty Propellers (c) R257/4-30-4/ DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers
propeller Dowty Propellers (c) R184/4-30-4/ DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers
propeller Dowty Propellers (c) R193/4-30-4/ DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers
propeller Dowty Propellers (c) R257/4-30-4/ DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers

Unsafe Condition

Failure of the propeller hub driving center, part number RA 57500, due to cracks.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Incorporate Dowty Rotol Modification (c) VP.2486 per Service Bulletin 61.573B or equivalent. Inspect hubs with magnifying glass and magnetic particle fluid method per SB 61-633. Replace cracked driving centers before flight. For R.184/4-30-4/50 propellers, inspections and modifications depend on hours time in service as specified.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within the next 4500 hours time in service after the effective date for most propellers, or as specified for R.184/4-30-4/50 based on their time in service on the effective date.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Dowty Rotol propellers models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 installed on specific aircraft models as listed.

AI-generated summary from the source AD text. Verify against the official source before acting.

Applicability Source Text

Show captured applicability text from the source AD
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AD Number:
68-20-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers
Subject:
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/08/1968
Make:
Dowty Propellers
Model:
(c) R184/4-30-4/ | (c) R193/4-30-4/ | (c) R257/4-30-4/
Product Type:
Propeller
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 68-20-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-664

AD NUMBER:   68-20-07

SUBJECT HEADING:   DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers

ACTION:  

SUMMARY:  

DATES:   Effective October 8, 1968.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   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.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_68-20-07.html
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Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
68-20-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers
Subject:
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/08/1968
Make:
Dowty Propellers
Model:
(c) R184/4-30-4/ | (c) R193/4-30-4/ | (c) R257/4-30-4/
Product Type:
Propeller
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 68-20-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-664

AD NUMBER:   68-20-07

SUBJECT HEADING:   DOWTY ROTOL Models (c) R.193/4-30-4/50, (c) R.257/4-30-4/60, and (c) R.184/4-30-4/50 Propellers

ACTION:  

SUMMARY:  

DATES:   Effective October 8, 1968.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   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.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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