AD 74-10-11

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AD Number:
74-10-11
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; AIRESEARCH: Applies to Model TSCP 700-4B Auxiliary Power Units (APU) Ins...Show more
Subject:
Auxiliary Power Units
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/14/1974
Make:
Airesearch | The Boeing Company
Model:
Auxiliary Power Units | DC-10-10 | DC-10-10F | DC-10-15 | DC-10-30 | DC-10-30F (KC-10A, KDC-10) | DC...Show more
Product Type:
Appliance
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Superseded AD: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Superseded By: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: 74-10-11
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-1869

AD NUMBER:   74-10-11

SUBJECT HEADING:   Airworthiness Directives; AIRESEARCH: Applies to Model TSCP 700-4B Auxiliary Power Units (APU) Installed in McDonnell Douglas Model DC-10 Aircraft

ACTION:  

SUMMARY:  

DATES:   Effective June 14, 1974.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   74-10-11 AIRESEARCH: Amendment 39-1837 as amended by Amendment 39-1869. Applies to Model TSCP 700-4B Auxiliary Power Units (APU) installed in McDonnell Douglas Model DC-10 aircraft.

"Pursuant to the authority of the Federal Aviation Act of 1958, delegated to me by the Administrator the following airworthiness directive applicable to AiResearch Model TSCP 700- 4B Auxiliary Power Units (APU) (installed in McDonnell-Douglas Model DC-10 Series Aircraft) is effective immediately upon receipt of this telegram because of numerous reports of fatigue cracks in the fuel control differential pressure regulator body. The presence of crack(s) can allow fuel to leak into the APU compartment. Compliance required as indicated, unless already accomplished.

(a) Within 25 hours additional time in service after the effective date of this AD, as amended, unless already accomplished, install a placard in view of the flight crew to prohibit all in-flight operation of the APU. Thereafter the APU may not be used in flight but may be used in ground operations."

(b) The operating restriction prescribed in (a), above, may be removed when the inspections and modifications described in paragraph 2.B. and C. of AiResearch Service Bulletin 969900-49-3635, Revision 1, dated May 14, 1974, or later FAA-approved revisions, are accomplished. Differential pressure regulator body assembly P/N 977320-1 or -2 which does not meet the wall thickness and fillet radius requirements specified in the referenced Service Bulletin must be rendered unserviceable. Those found satisfactory or that can be reworked per the instructions contained in paragraph 2.B.(4) of the referenced Service Bulletin must be re- identified as P/N 977320-4 and may be continued in service. Re-identify the fuel control assembly per paragraph 2.D. of the referenced service bulletin."

(c) Within 3000 APU operating cycles in service after accomplishment of paragraph (b), above, and at intervals not to exceed 3000 APU operating cycles in service thereafter, inspect the fuel control differential pressure regulator body, P/N 977320-4, for cracks in accordance with paragraph 2.B.(2) of AiResearch Service Bulletin 969900-49-3635. If cracks are found, replace the housing with a serviceable housing conforming to P/N 977320-4, prior to further in-flight operation.

Note: For the purpose of this AD, an APU operating cycle is any operation consisting of a start and shut-down. The number of cycles may be determined by actual count, or, subject to acceptance by the assigned FAA Maintenance Inspector, may be calculated by dividing the fuel control assembly time in service by the operator's fleet average APU operating time per APU operating cycle.

(d) The inspections prescribed in (c) above may be discontinued when the fuel control differential pressure regulator body assembly P/N 977320-4 is replaced with a new part conforming to P/N 977656-1.

(e) Equivalent procedures may be approved by the Chief, Aircraft Engineering Division, FAA Western Region, upon submission of adequate substantiation data.

Amendment 39-1837 was effective May 13, 1974, for all persons except those to whom it was made effective immediately by telegram dated April 17, 1974.

This Amendment 39-1869 becomes effective June 14, 1974.

FOOTER: