[Federal Register Volume 61, Number 207 (Thursday, October 24, 1996)]
[Rules and Regulations]
[Pages 55084-55085]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-26719]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-07-AD; Amendment 39-9785; AD 96-21-08]
RIN 2120-AA64


Airworthiness Directives; Short Brothers Model SD3-30 and SD3-
SHERPA 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 to all Short Brothers Model SD3-30 and SD3-SHERPA series 
airplanes, that requires inspections of the vertical fin-to-tailplane 
joint to detect any loose bolts; and, if necessary, inspections to 
detect elongation of bolt holes, and replacement with new bolts, if 
necessary. Additionally, this amendment requires inspections of the 
upper shear angle to detect pulled or loose rivets, and replacement of 
the shear angle using new rivets, if necessary. This amendment is 
prompted by reports of loose bolts in the vertical fin-to-tailplane 
joint and pulled or loose rivets in an upper shear angle. The actions 
specified by this AD are intended to prevent reduced structural 
integrity of the vertical fin to tailplane joint due to such 
discrepancies of the bolts or rivets.

DATES: Effective November 29, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 29, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from Short Brothers plc, 2011 Crystal Drive, Suite 713, 
Arlington, Virginia 22202-3719. 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: Greg Dunn, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2799; fax (206) 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 all Short Brothers Model SD3-30 
and SD3-SHERPA series airplanes was published in the Federal Register 
on August 1, 1996 (61 FR 40159). That action proposed to require 
inspections of the vertical fin-to-tailplane joint to detect any loose 
bolts; and, if necessary, inspections to detect elongation of bolt 
holes, and replacement with new bolts, if necessary. Additionally, that 
action proposed to require inspections of the upper shear angle to 
detect pulled or loose rivets, and replacement of the shear angle using 
new rivets, 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 66 Short Brothers Model SD3-30 and SD3-
SHERPA series airplanes of U.S. registry will be affected by this AD, 
that it will take approximately 74 work hours 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 $293,040, or $4,440 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

[[Page 55085]]

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:

96-21-08 Short Brothers, PLC: Amendment 39-9785. Docket 96-NM-07-AD.

    Applicability: All Model SD3-30 and SD3-SHERPA 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 
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 reduced structural integrity of the vertical fin to 
tailplane joint, accomplish the following:
    (a) Within 60 days after the effective date of this AD, perform 
a visual inspection to detect loose bolts in the vertical fin to 
tailplane joint, in accordance with Shorts Service Bulletin SD330-
55-18, dated April 20, 1995 (for Model SD3-30 airplanes), or Shorts 
SD3 SHERPA Service Bulletin SD3 SHERPA-55-1, dated April 20, 1995 
(for Model SD3-SHERPA airplanes), as applicable.
    (1) If no loose bolt is found, repeat the visual inspection 
thereafter at intervals not to exceed 1,500 flight hours.
    (2) If any loose bolt is detected, inspect the bolt for wear and 
distortion and inspect the hole for elongation, in accordance with 
the applicable service bulletin.
    (i) If the bolt and hole are within the limits specified by the 
applicable service bulletin, prior to further flight, refit the bolt 
with a new nut and washers, in accordance with the applicable 
service bulletin. Repeat the visual inspection thereafter at 
intervals not to exceed 1,500 flight hours.
    (ii) If the bolt is worn or distorted and the hole is within the 
limits specified by the applicable service bulletin, prior to 
further flight, replace the bolt, nut, and washers with a new bolt, 
a new nut, and new washers, in accordance with the applicable 
service bulletin. Repeat the visual inspection thereafter at 
intervals not to exceed 1,500 flight hours.
    (iii) If the hole is elongated within the limits specified in 
the applicable service bulletin, prior to further flight, oversize 
the diameter of the hole, and replace the bolt, nut, and washers 
with a new matching bolt, new nut, and new washers, in accordance 
with the applicable service bulletin. Repeat the visual inspection 
thereafter at intervals not to exceed 1,500 flight hours.
    (iv) If the hole is elongated beyond the limits specified in the 
applicable service bulletin, prior to further flight, repair in 
accordance with a method approved by the Manager, Standardization 
Branch, ANM-113, FAA, Transport Airplane Directorate.
    (b) Within 60 days after the effective date of this AD, perform 
a visual inspection to detect looseness or pulling of the rivets of 
attach shear angles SD3-32-0217/K and SD3-32-0218/K. If any 
looseness or pulling of the rivets is detected, prior to further 
flight, replace the shear angle using oversize rivets, in accordance 
with the applicable service bulletin.
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the ANM-113.

    (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 Shorts Service 
Bulletin SD330-55-18, dated April 20, 1995, or Shorts SD3 SHERPA 
Service Bulletin SD3 SHERPA-55-1, dated April 20, 1995, as 
applicable. 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 Short Brothers plc, 
2011 Crystal Drive, Suite 713, Arlington, Virginia 22202-3719. 
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.
    (f) This amendment becomes effective on November 29, 1996.

    Issued in Renton, Washington, on October 10, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-26719 Filed 10-23-96; 8:45 am]
BILLING CODE 4910-13-U