[Federal Register Volume 62, Number 229 (Friday, November 28, 1997)]
[Rules and Regulations]
[Pages 63264-63266]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-31027]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-189-AD; Amendment 39-10220; AD 97-24-13]
RIN 2120-AA64


Airworthiness Directives; British Aerospace BAe Model ATP 
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 British Aerospace BAe Model ATP airplanes, that 
requires a detailed visual inspection of the flap drive torque tubes in 
the wing root area to detect inadequate clearance between the torque 
tubes and surrounding structure or scoring damage to the tubes; and 
follow-on repetitive inspections or corrective action, if necessary. 
Accomplishment of certain replacements and modifications would 
constitute terminating action for the repetitive inspections. This 
amendment is prompted by reports of inadequate clearance between flap 
drive torque tubes and surrounding structures, and possible scoring 
damage to the tubes. The actions specified by this AD are intended to 
prevent failure of the torque tubes, which could result in an 
asymmetric flap condition and reduced controllability of the airplane.

DATES: Effective January 2, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 2, 1998.

ADDRESSES: The service information referenced in this AD may be 
obtained from AI(R) American Support, Inc., 13850 Mclearen Road, 
Herndon, Virginia 20171. 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 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: International Branch, ANM-116, FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

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 certain British Aerospace BAe 
Model ATP airplanes was published in the Federal Register

[[Page 63265]]

on August 25, 1997 (62 FR 44917). That action proposed to require a 
detailed visual inspection of the flap drive torque tubes in the wing 
root area to detect inadequate clearance between the torque tubes and 
surrounding structure or scoring damage to the tubes; and follow-on 
repetitive inspections or corrective action, if necessary.

Comments

    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 10 British Aerospace BAe Model ATP 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 $600, 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:

97-24-13  British Aerospace Regional Aircraft [Formerly Jetstream 
Aircraft Limited, British Aerospace (Commercial Aircraft) Limited]: 
Amendment 39-10220. Docket 96-NM-189-AD.

    Applicability: BAe Model ATP airplanes, constructor numbers 2002 
through 2063 inclusive; 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 (c) 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 failure of the torque tubes, which could result in an 
asymmetric flap condition and reduced controllability of the 
airplane, accomplish the following:
    (a) Within 90 days after the effective date of this AD, conduct 
a detailed visual inspection of the flap drive torque tubes in the 
left and right wing root areas to detect inadequate clearance 
between the torque tubes and surrounding structure or scoring damage 
to the tubes, in accordance with Jetstream Service Bulletin ATP-27-
80, dated April 23, 1996.
    (1) If adequate clearance exists between all flap drive torque 
tubes and surrounding structure at the sites specified in the 
service bulletin, with no scoring damage to any of the tubes, no 
further action is required by this AD.
    (2) If inadequate clearance exists between any flap drive torque 
tube and surrounding structure at the sites specified in the service 
bulletin, with no scoring damage to the tubes: Accomplish the 
requirements of paragraphs (a)(2)(i) and (a)(2)(ii) of this AD.
    (i) At intervals not to exceed 250 hours time-in-service, repeat 
the detailed visual inspections required by paragraph (a) of this 
AD.
    (ii) Within 2,000 hours time-in-service after the initial 
inspection required by paragraph (a) of this AD, modify the 
structure to gain the required minimum clearance in accordance with 
the service bulletin. Accomplishment of the modification constitutes 
terminating action for the repetitive inspection requirement of 
paragraph (a)(2)(ii) of this AD.
    (3) If any scoring damage to the torque tubes is detected, 
accomplish the requirements specified in paragraph (a)(3)(i), 
(a)(3)(ii), or (a)(3)(iii) of this AD, as applicable, in accordance 
with the service bulletin, and at the time specified in the 
applicable paragraph.
    (i) If only one torque tube on one side or both sides of the 
airplane is damaged, and the scoring is within the maximum allowable 
damage limits in the service bulletin: Within 250 hours time-in-
service after any inspection required by this AD in which the damage 
was initially detected, modify the surrounding structure to gain the 
required minimum clearance and install a new torque tube.
    (ii) If both torque tubes on the same side of the airplane are 
damaged, and the scoring is within the maximum allowable damage 
limits in the service bulletin: Prior to further flight after any 
inspection required by this AD in which damage was initially 
detected, modify the surrounding structure to gain the required 
minimum clearance and replace at least one of the damaged torque 
tubes with a new torque tube. Within 250 hours time-in-service after 
any inspection in which damage was initially detected, replace the 
remaining damaged torque tube with a new torque tube.
    (iii) If any torque tube is damaged, and the scoring is more 
than the allowable damage limits described in the service bulletin: 
Prior to further flight, modify the surrounding structure to gain 
the required minimum clearance and replace the damaged tube(s) with 
a new torque tube(s).
    (b) Accomplishment of the modification to gain the required 
minimum clearance between the torque tubes and surrounding structure 
and the replacement of damaged torque tube(s) with a new torque 
tube(s) constitutes terminating action for the requirements of this 
AD.
    (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, International Branch, ANM-116, FAA, 
Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, International 
Branch, ANM-116.


[[Page 63266]]


    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (d) 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.
    (e) The actions shall be done in accordance with Jetstream 
Service Bulletin ATP-27-80, dated April 23, 1996. 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 AI(R) American Support, Inc., 13850 Mclearen Road, 
Herndon, Virginia 20171. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

    Note 3: The subject of this AD is addressed in British 
airworthiness directive 003-04-96.

    (f) This amendment becomes effective on January 2, 1998.

    Issued in Renton, Washington, on November 19, 1997.
Stewart R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-31027 Filed 11-26-97; 8:45 am]
BILLING CODE 4910-13-U