AD 79-10-09

final rule

Airworthiness Directives; Hughes Model 369D Helicopters

AD Number
79-10-09
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft MD Helicopters, Inc. 369D Airworthiness Directives; Hughes Model 369D Helicopters

Unsafe Condition

Failure of the tail rotor pitch control assembly, which could result in loss of tail rotor control.

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

Required Actions

Check the locknut and tang washer of the tail rotor pitch control assembly before further flight. If loose, replace the assembly with a serviceable one having a white dot on the locknut. Repeat checks before each engine start-up until termination action per DN-37. Operators complying with DN-37 must replace assemblies within 150 hours time in service or accomplish DN-37 within 100 hours depending on prior repair status.

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

Compliance Time

Before further flight after the effective date of this AD

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

Affected Aircraft

Hughes Model 369D Helicopters except Serial Numbers 0409 and subsequent

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

Federal Register Abstract

Tail Rotor Pitch Control Assy

Applicability Source Text

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AD Number:
79-10-09
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Hughes Model 369D Helicopters
Subject:
Tail Rotor Pitch Control Assy
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/17/1979
Make:
MD Helicopters, Inc.
Model:
369D
Product Type:
Aircraft
Product Subtype:
Rotorcraft
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 79-10-09
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3466

AD NUMBER:   79-10-09

SUBJECT HEADING:   Airworthiness Directives; Hughes Model 369D Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective May 17, 1979.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
79-10-09 HUGHES HELICOPTERS: Amendment 39-3466. Applies to Hughes Model 369D Helicopters certificated in all categories, except Serial Numbers 0409 and subsequent.

Compliance required as indicated.

To prevent failure of the tail rotor pitch control assembly, which could result in loss of tail rotor control, accomplish the following:

(a) Before further flight after the effective date of this AD, check the 369D21803-3 locknut and tang washer P/N MS172209 or HS1551S238 of the tail rotor pitch control assembly P/N 369D21800 as follows:

Pull back the non-rotating boot P/N 369D21806 from the tail rotor pitch control assembly P/N 369D21800 and check the locknut and tang washer by hand for looseness.

(1) If the locknut or tang washer is loose, remove and replace the tail rotor pitch control assembly with a serviceable assembly with a white dot on the locknut, before further flight.

(2) If either the locknut or tang washer is not loose, repeat the check for looseness of the locknut or tang washer before each engine start-up. See (c) below for termination action.

The checks required by this AD may be performed by the pilot.

NOTE 1: For the requirements regarding the listing of compliance and method of compliance with this AD in the helicopter's permanent maintenance record, see FAR 91.173.

(b) For the operators that have previously complied with Hughes Service Information Notice DN-37, dated December 1, 1978, the following applies:

(1) If the tail rotor pitch control assembly was repaired due to looseness of the locknut or tang washer, repeat the checks in (a) above and remove and replace the tail rotor pitch control assembly within 150 hours time in service after the receipt of the airmail letter dated April 9, 1979.

(2) For the tail rotor pitch control assemblies for which records of repair are not known, see (b)(1) above.

(3) For the tail rotor pitch control assemblies which were repaired per DN- 37 with no looseness of the locknut or tang washer, the requirements of this AD do not apply.

NOTE 2: The pitch control assemblies which have loose locknut or tang washers must be overhauled per the Hughes Model 369D Helicopter Basic Handbook of Maintenance Instructions and DN-37, dated December 1, 1978, before return to service.

(c) For those assemblies which do not have loose tang washers or locknuts, per paragraph (a)(2) above, within 100 hours of time in service from the receipt of the airmail letter dated April 9, 1979, accomplish DN-37.

(d) Equivalent checks and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment becomes effective May 17, 1979, as to all persons except those persons to whom it was made immediately effective by the airmail letter dated April 9, 1979, which contained this amendment.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_79-10-09.html
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Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
79-10-09
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Hughes Model 369D Helicopters
Subject:
Tail Rotor Pitch Control Assy
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/17/1979
Make:
MD Helicopters, Inc.
Model:
369D
Product Type:
Aircraft
Product Subtype:
Rotorcraft
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 79-10-09
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3466

AD NUMBER:   79-10-09

SUBJECT HEADING:   Airworthiness Directives; Hughes Model 369D Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective May 17, 1979.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
79-10-09 HUGHES HELICOPTERS: Amendment 39-3466. Applies to Hughes Model 369D Helicopters certificated in all categories, except Serial Numbers 0409 and subsequent.

Compliance required as indicated.

To prevent failure of the tail rotor pitch control assembly, which could result in loss of tail rotor control, accomplish the following:

(a) Before further flight after the effective date of this AD, check the 369D21803-3 locknut and tang washer P/N MS172209 or HS1551S238 of the tail rotor pitch control assembly P/N 369D21800 as follows:

Pull back the non-rotating boot P/N 369D21806 from the tail rotor pitch control assembly P/N 369D21800 and check the locknut and tang washer by hand for looseness.

(1) If the locknut or tang washer is loose, remove and replace the tail rotor pitch control assembly with a serviceable assembly with a white dot on the locknut, before further flight.

(2) If either the locknut or tang washer is not loose, repeat the check for looseness of the locknut or tang washer before each engine start-up. See (c) below for termination action.

The checks required by this AD may be performed by the pilot.

NOTE 1: For the requirements regarding the listing of compliance and method of compliance with this AD in the helicopter's permanent maintenance record, see FAR 91.173.

(b) For the operators that have previously complied with Hughes Service Information Notice DN-37, dated December 1, 1978, the following applies:

(1) If the tail rotor pitch control assembly was repaired due to looseness of the locknut or tang washer, repeat the checks in (a) above and remove and replace the tail rotor pitch control assembly within 150 hours time in service after the receipt of the airmail letter dated April 9, 1979.

(2) For the tail rotor pitch control assemblies for which records of repair are not known, see (b)(1) above.

(3) For the tail rotor pitch control assemblies which were repaired per DN- 37 with no looseness of the locknut or tang washer, the requirements of this AD do not apply.

NOTE 2: The pitch control assemblies which have loose locknut or tang washers must be overhauled per the Hughes Model 369D Helicopter Basic Handbook of Maintenance Instructions and DN-37, dated December 1, 1978, before return to service.

(c) For those assemblies which do not have loose tang washers or locknuts, per paragraph (a)(2) above, within 100 hours of time in service from the receipt of the airmail letter dated April 9, 1979, accomplish DN-37.

(d) Equivalent checks and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment becomes effective May 17, 1979, as to all persons except those persons to whom it was made immediately effective by the airmail letter dated April 9, 1979, which contained this amendment.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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