[Federal Register Volume 61, Number 251 (Monday, December 30, 1996)]
[Rules and Regulations]
[Pages 68565-68566]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31525]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-265-AD; Amendment 39-9851; AD 96-25-08]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-7 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all de Havilland Model DHC-7 series airplanes, that 
requires performing a review of the airplane maintenance records to 
determine if any insulation blankets have been repaired or changed 
during service, and various follow-on actions, if necessary. This 
amendment is prompted by reports of corrosion forming on areas of the 
airplane structure where black film thermal insulation blankets are 
used. The actions specified by this AD are intended to prevent such 
corrosion, which could result in degradation of the structural 
capability of the airplane fuselage and consequent sudden loss of cabin 
pressure.

DATES: Effective February 3, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 3, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 
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, New York Aircraft Certification Office, 
Engine and Propeller Directorate, 10 Fifth Street, Third Floor, 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 and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, Engine and Propeller Directorate, 10 Fifth 
Street, Third Floor, Valley Stream, New York 11581; telephone (516) 
256-7522; fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all de Havilland Model DHC-7 
series airplanes was published in the Federal Register on September 30, 
1996 (61 FR 51062). That action proposed to require performing a review 
of the airplane maintenance records to determine if any insulation 
blankets have been repaired or changed during service, and various 
follow-on actions, if necessary.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 50 de Havilland Model DHC-7 series airplanes 
of U.S. registry will be affected by this AD, that it will take 
approximately 1 work hour per airplane to accomplish the required 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the cost impact of the AD on U.S. operators is estimated 
to be $3,000, or $60 per airplane.
    The 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.

Regulatory Impact

    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 part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

96-25-08  De Havilland, Inc.: Amendment 39-9851. Docket 95-NM-265-
AD.

    Applicability: All Model DHC-7 series airplanes, certificated in 
any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent degradation of the structural capability of the 
fuselage and sudden loss of cabin pressure, accomplish the 
following:
    (a) Within six months after the effective date of this AD, 
perform a review of the airplane maintenance records to determine if 
any insulation blankets have been repaired or changed during 
service, in accordance with

[[Page 68566]]

de Havilland Service Bulletin S.B. 7-21-30, dated July 6, 1994.
    (b) If no insulation blanket has been repaired or changed, no 
further action is required by this AD.
    (c) If any insulation blanket has been repaired or changed, 
prior to further flight, perform a visual inspection to detect black 
film insulation of the air conditioning system, in accordance with 
de Havilland Service Bulletin S.B. 7-21-30, dated July 6, 1994.
    (1) If no black film insulation is detected, prior to further 
flight, perform a review of the airplane modification records to 
determine if any kit listed in ``Table 1--Modification List'' has 
been installed, in accordance with the service bulletin.
    (i) If no kit listed in ``Table 1-Modification List'' is found 
to be installed, no further action is required by this AD.
    (ii) If any kit listed in ``Table 1-Modification List'' is found 
to be installed, prior to further flight, perform the various 
follow-on actions in accordance with the service bulletin. (The 
follow-on actions include an inspection to detect black film 
insulation, removal of any black film insulation, an inspection to 
detect corrosion, repair of corroded structure, and installation of 
new silver blankets.) However, in lieu of repairing corroded 
structure in accordance with service bulletin, the repair of any 
corrosion shall be done in accordance with a method approved by the 
Manager, New York Aircraft Certification Office (ACO), FAA, Engine 
and Propeller Directorate.
    (2) If any black film insulation is detected, prior to further 
flight, perform the follow-on actions in accordance with the service 
bulletin. (The follow-on actions include removal of any black film 
insulation, an inspection to detect corrosion, repair of any 
corroded structure, and installation of new silver blankets.) 
However, in lieu of repairing corroded structure in accordance with 
service bulletin, the repair of any corrosion shall be done in 
accordance with a method approved by the Manager, New York ACO.
    (d) As of the effective date of this AD, no person shall install 
black Orcon film insulation, part number AN46B/AN36B, on any 
airplane.
    (e) 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, 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

    (f) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (g) The actions shall be done in accordance with de Havilland 
Service Bulletin S.B. 7-21-30, dated July 6, 1994. 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 Bombardier, Inc., Bombardier 
Regional Aircraft Division, 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, New York Aircraft Certification Office, Engine and 
Propeller Directorate, 10 Fifth Street, Third Floor, Valley Stream, 
New York; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (h) This amendment becomes effective on February 3, 1997.

    Issued in Renton, Washington, on December 5, 1996.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-31525 Filed 12-27-96; 8:45 am]
BILLING CODE 4910-13-U