[Federal Register Volume 59, Number 86 (Thursday, May 5, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-9730]


[[Page Unknown]]

[Federal Register: May 5, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 92-NM-157-AD; Amendment 39-8893; AD 94-09-05]

 

Airworthiness Directives; de Havilland, Inc., Model DHC-7 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain de Havilland Model DHC-7 series airplanes, that 
requires a one-time inspection to assess the adequacy of the clearance 
between various adapter plates and seal retaining angles on the 
fuselage side access panel, and modification of both the forward and 
rear seal retention angles. This amendment is prompted by reports of 
incidents involving corrosion and fatigue cracking in commuter-class 
airplanes that are approaching or have exceeded their economic design 
goal. The actions specified by this AD are intended to prevent 
degradation of the structural capabilities of the affected airplanes.

DATES: Effective June 6, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 6, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from de Havilland, Inc., Garratt Boulevard, Downsview, Ontario 
M3K 1Y5, Canada. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, 
Engine and Propeller Directorate, New York Aircraft Certification 
Office, 181 South Franklin Avenue, room 202, Valley Stream, New York; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Sol Maroof, Aerospace Engineer, 
Airframe Branch, ANE-172, FAA, New York Aircraft Certification Office, 
181 South Franklin Avenue, room 202, Valley Stream, New York 11581; 
telephone (516) 791-6220; fax (516) 791-9024.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to certain de Havilland Model DHC-7 series airplanes was 
published as a supplemental notice of proposed rulemaking (NPRM) in the 
Federal Register on January 4, 1994 (59 FR 266). That action proposed 
to require a one-time inspection to assess the adequacy of the 
clearance between various adapter plates and seal retaining angles on 
the fuselage side access panel, and modification of both the forward 
and rear seal retention angles.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.
    The commenter supports the proposed rule.
    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.
    The FAA estimates that 44 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 8 work hours per 
airplane to accomplish the modifications and inspections, and that the 
average labor rate is $55 per work hour. Required parts will be nominal 
in cost. Based on these figures, the total cost impact of the AD on 
U.S. operators is estimated to be $19,360, or $440 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES. 

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-09-05 De Havilland, Inc.: Amendment 39-8893. Docket 92-NM-157-AD.

    Applicability: Model DHC-7 series airplanes having serial 
numbers 1 through 99 inclusive, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent structural failure, accomplish the following:
    (a) For airplanes having serial numbers 1 through 77 inclusive, 
79 through 83 inclusive, 85, and 86: Within 12 months after the 
effective date of this AD, inspect the clearance between the wing 
forward pick-up adapter plates and the seal retaining angle on the 
fuselage side access panel in accordance with de Havilland Service 
Bulletin 7-57-11, dated December 17, 1982.
    (1) If the adapter plates are undamaged or if scoring on the 
adapter plates does not exceed 0.050 inch in depth, prior to further 
flight, accomplish Modification 7/2319 in accordance with the 
service bulletin.
    (2) If scoring on the adapter plates is equal to or exceeds 
0.050 inch in depth, prior to further flight, repair in accordance 
with a method approved by the Manager, New York Aircraft 
Certification Office (ACO), ANE-170, FAA, Engine and Propeller 
Directorate.
    (b) For airplanes having serial numbers 1 through 99 inclusive: 
Within 12 months after the effective date of this AD, inspect the 
clearance between the rear mounting adapter plates and the seal 
retaining angle on the fuselage side access panel in accordance with 
de Havilland Service Bulletin 7-57-19, dated February 24, 1984.
    (1) If the adapter plates are undamaged or if scoring on the 
adapter plates does not exceed 0.050 inch in depth, prior to further 
flight, accomplish Modification 7/2355 in accordance with the 
service bulletin.
    (2) If scoring on the adapter plates is equal to or exceeds 
0.050 inch in depth, prior to further flight, repair in accordance 
with a method approved by the Manager, New York ACO, ANE-170, FAA, 
Engine and Propeller Directorate.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, New York ACO, ANE-170, FAA, Engine 
and Propeller Directorate. Operators shall submit their requests 
through an appropriate FAA Principal Maintenance Inspector, who may 
add comments and then send it to the Manager, New York ACO.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

    (d) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the 
airplane to a location where the requirements of this AD can be 
accomplished.
    (e) The inspections and modifications shall be done in 
accordance with de Havilland Service Bulletin 7-57-11, dated 
December 17, 1982, and de Havilland Service Bulletin 7-57-19, dated 
February 24, 1984. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR Part 51. Copies may be obtained from de Havilland, 
Inc., Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies 
may be inspected at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and 
Propeller Directorate, New York Aircraft Certification Office, 181 
South Franklin Avenue, Room 202, Valley Stream, New York; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.
    (f) This amendment becomes effective on June 6, 1994.

    Issued in Renton, Washington, on April 18, 1994.
Darrell M. Pederson, Acting Manager,
Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 94-9730 Filed 5-4-94; 8:45 am]
BILLING CODE 4910-13-U