AD 71-19-04

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AD Number:
71-19-04
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; BRITISH AIRCRAFT CORPORATION Models 744 and 745D Airplanes
Subject:
Placard On Cabin Pressurization
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
08/06/1971
Make:
Vickers-Armstrongs (Aircraft Limited)
Model:
Viscount 744 | Viscount 745D
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 71-19-04
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-1286

AD NUMBER:   71-19-04

SUBJECT HEADING:   Airworthiness Directives; BRITISH AIRCRAFT CORPORATION Models 744 and 745D Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective August 6, 1971.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
71-19-04 BRITISH AIRCRAFT CORPORATION: Amdt. 39-1286. Applies to Viscount Models 744 and 745D airplanes.

Compliance is required as indicated.

To prevent cabin depressurization due to leakage through cracks in the rear pressure bulkhead boundary member accomplish the following:

(a) For airplanes that have accumulated 25,000 or more landings on the effective date of this AD -

(1) Before further flight install an operating limitation placard in the pilot's compartment in clear view of the pilot prohibiting further flight at a cabin pressure differential exceeding 3.5 p.s.i. and

(2) Within the next 25 landings after the effective date of this AD comply with paragraph (d).

(b) For airplanes that have accumulated 20,000 or more landings but less than 25,000 landings on the effective date of this AD -

(1) Before further flight install an operating limitation placard in the pilot's compartment in clear view of the pilot prohibiting further flight at a cabin pressure differential exceeding 4.5 p.s.i. and

(2) Within the next 50 landings after the effective date of this AD comply with paragraph (d).

(c) For airplanes that have accumulated less than 20,000 landings on the effective date of this AD, before the accumulation of 20,000 landings or before the accumulation of 100 landings after the effective date of this AD, whichever occurs later, comply with paragraph (d).

(d) Inspect the rear pressure bulkhead boundary member around the complete circumference of the boundary member for cracks -

(1) Using the eddy current method, with a standard pencil non ferrous probe, along the forward inside bend radius of the boundary member, or

(2) Visually inspect using a magnifying lens of at least 10 powers.

(e) If any cracks in the boundary member are found during the inspection required by paragraph (d), before further flight repair the cracked boundary member -

(1) By reinforcing the cracked portion of the boundary member with a length of serviceable boundary member section which extends at least three inches beyond the extremities of any crack; or

(2) By replacing the cracked portion with a length of serviceable boundary member section; connecting the replacement section by typical type joint plates.

(f) The placard required by paragraph (a) or (b) may be removed after paragraph (d) and paragraph (e), if applicable, have been accomplished.

(g) For the purpose of complying with this AD, subject to acceptance by the assigned FAA maintenance inspector, the number of landings may be determined by dividing each airplane's hours' time in service by the operator's fleet average time from takeoff to landing for the airplane type.

(BAC campaign wire SS1073V refers to this subject.)

This amendment is effective upon publication in the Federal Register as to all persons except those persons to whom it was made immediately effective upon receipt of the airmail letter dated August 6, 1971, which contained this amendment.

FOOTER: