[Federal Register Volume 59, Number 72 (Thursday, April 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-8818]


[[Page Unknown]]

[Federal Register: April 14, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 91-CE-47-AD; Amendment 39-8882; AD 94-08-10]

 

Airworthiness Directives: de Havilland DHC-6 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 88-13-
11, which currently requires repetitively inspecting both wing main 
spar lower cap angles for corrosion, and repairing or replacing any 
corroded part. This action retains these inspection and possible repair 
or replacement requirements, but eliminates the dual compliance time of 
both hours time-in-service (TIS) and calendar time. The Federal 
Aviation Administration (FAA) has determined that, since corrosion 
occurs regardless of whether the airplane is in service, the best 
compliance method for the proposed action is calendar time. The actions 
specified by this AD are intended to prevent failure of the wing 
structure because of corroded wing main spar lower cap angles.

DATES: Effective June 13, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 13, 1994.

ADDRESSES: Service information that applies to this AD may be obtained 
from de Havilland, Inc., 123 Garratt Boulevard, Downsview, Ontario, 
Canada, M3K 1Y5. This information may also be examined at the FAA, 
Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 
E. 12th Street, Kansas City, Missouri 64106; or at the Office of the 
Federal Register, 800 North Capitol Street NW., suite 700, Washington, 
DC.

FOR FURTHER INFORMATION CONTACT: Jon Hjelm, Aerospace Engineer, FAA, 
New York Aircraft Certification Office, 181 South Franklin Avenue, Room 
202, Valley Stream, New York 11581; telephone (516) 791-6220.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an AD that would apply to certain de 
Havilland DHC-6 series airplanes was published in the Federal Register 
on December 28, 1993 (58 FR 68575). The action proposed to supersede AD 
88-13-11 with a new AD that would retain the requirement of 
repetitively inspecting both wing main spar lower cap angles for 
corrosion, but require these inspections with a compliance method based 
solely on calendar time. The proposed actions would be accomplished in 
accordance with the Accomplishment Instructions section of de Havilland 
Service Bulletin No. 6/492, Revision A, dated October 23, 1987.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. One comment was received in support of 
the proposed rule.
    After careful review of all available information, the FAA has 
determined that air safety and the public interest require the adoption 
of the rule as proposed except for minor editorial corrections. The FAA 
has determined that these minor corrections will not change the meaning 
of the AD nor add any additional burden upon the public than was 
already proposed.
    The FAA estimates that 169 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 8 workhours per 
airplane to accomplish the required initial inspection, and that the 
average labor rate is approximately $55 an hour. Based on these 
figures, the total cost impact of the AD on U.S. operators is estimated 
to be $74,360. This figure does not account for repetitive inspections. 
The only difference between this AD and AD 88-13-11, which will be 
superseded by this required action, is limiting the compliance method 
to only calendar time instead of both calendar time and hours TIS. 
Therefore, the required action will not impose any additional cost 
impact upon the public than that which is already required by AD 88-13-
11.
    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 copy of the final evaluation prepared for this 
action is contained in the Rules Docket. A copy of it may be obtained 
by contacting 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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing AD 88-13-11, Amendment 39-
5960 (53 FR 23755, June 24, 1988), and by adding a new airworthiness 
directive to read as follows:

94-08-10 de Havilland: Amendment 39-8882; Docket No. 91-CE-47-AD. 
Supersedes AD 88-13-11, Amendment 39-5960.

    Applicability: Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-
300 airplanes (all serial numbers), certificated in any category.
    Compliance: Required initially in accordance with whichever of 
the following is applicable, unless already accomplished, and 
thereafter at intervals not to exceed 60 calendar months:
     Upon the accumulation of 120 calendar months from the 
date of manufacture or within the next 3 calendar months after the 
effective date of this AD, whichever occurs later;
     Upon the accumulation of 120 calendar months after 
incorporating Wing Box Replacement Modification No. 6/1630 in 
accordance with de Havilland Service Bulletin (SB) No. 6/362, 
Revision 1, dated January 18, 1985, or within the next 3 calendar 
months after the effective date of this AD, whichever occurs later; 
or
     Upon the accumulation of 120 calendar months of 
original manufacture of wings if used wings have been installed on 
the airplane or within the next 3 calendar months after the 
effective date of this AD, whichever occurs later.
    To prevent failure of the wing structure because of corroded 
wing main spar lower cap angles, accomplish the following:
    (a) Visually inspect the wing main spar and lower spar cap 
extensions for corrosion using a high intensity light in accordance 
with paragraph A in the ACCOMPLISHMENT INSTRUCTIONS section of de 
Havilland SB No. 6/492, Revision A, dated October 23, 1987.
    (b) If corrosion is found during the inspection required by 
paragraph (a) of this AD that exceeds the criteria specified in the 
COMPLIANCE section of de Havilland SB No. 6/492, Revision A, dated 
October 23, 1987, prior to further flight, accomplish the following:
    (1) Remove all surface corrosion and replace the cap angles in 
accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de 
Havilland SB No. 6/492, Revision A, dated October 23, 1987.
    (2) Dye penetrant inspect all parts where corrosion was removed 
to ensure that the part is corrosion-free. Replace any parts that 
have corrosion damage and reprotect reworked areas utilizing 
information specified in de Havilland Technical Advisory Bulletin 
No. 626/1, dated November 1970.
    (c) If any parts are reworked per the inspection result 
requirements of this AD, prior to further flight, accomplish the 
following:
    (1) Submit the details of all reworked areas to the manufacturer 
through the New York Aircraft Certification Office (ACO) at the 
address specified in paragraph (e) of this AD; and
    (2) Incorporate any additional instructions provided by the New 
York ACO as a condition for returning the airplane to service.
    (d) Special flight permits may be issued in accordance with 14 
CFR 21.197 and 21.199 to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (e) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, New York ACO, FAA, 
181 South Franklin Avenue, room 202, Valley Stream, New York 11581. 
The request shall be forwarded through an appropriate FAA 
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.

    (f) The inspections and repair or replacement (as necessary) 
required by this AD shall be done in accordance with de Havilland 
Service Bulletin No. 6/492, Revision A, dated October 23, 1987. 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., 123 Garratt 
Boulevard, Downsview, Ontario, Canada, M3K 1Y5. Copies may be 
inspected at the FAA, Central Region, Office of the Assistant Chief 
Counsel, room 1558, 601 E. 12th Street, Kansas City, Missouri, or at 
the Office of the Federal Register, 800 North Capitol Street NW., 
suite 700, Washington, DC.
    (g) This amendment (39-8882) supersedes AD 88-13-11, Amendment 
39-5960.
    (h) This amendment (39-8882) becomes effective on June 13, 1994.

    Issued in Kansas City, Missouri, on April 7, 1994.
Larry D. Malir,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-8818 Filed 4-13-94; 8:45 am]
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