AD Amdt-39-9533

[Federal Register Volume 61, Number 48 (Monday, March 11, 1996)]
[Rules and Regulations]
[Pages 9599-9601]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 96-5369]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-72-AD; Amendment 39-9533; AD 96-05-07]


Airworthiness Directives; Boeing Model 757 Series Airplanes 
Equipped with Pratt & Whitney Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 757 series airplanes, that 
currently requires repetitive inspections to detect cracking in the 
midspar fuse pins and replacement of certain fuse pins. This amendment 
requires inspection of certain fuse pins, and replacement of certain 
fuse pins with certain other fuse pins. This amendment also requires 
inspections of refinished straight fuse pins and replacement of cracked 
refinished straight fuse pins with certain other straight fuse pins. 
This amendment is prompted by the development of new corrosion-
resistant steel fuse pins. The actions specified by this AD are 
intended to prevent cracking of the midspar fuse pins, which may lead 
to separation of the strut and engine from the wing of the airplane.

DATES: Effective April 10, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 10, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. 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 

[[Page 9600]]
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

FOR FURTHER INFORMATION CONTACT: Carrie Sumner, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (206) 227-2778; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 93-16-09, 
amendment 39-8666 (58 FR 45044, August 26, 1993), which is applicable 
to certain Boeing Model 757 series airplanes, was published as a 
supplemental notice of proposed rulemaking in the Federal Register on 
June 8, 1995 (60 FR 30208). The action proposed to require:
    1. Inspections to detect cracking of straight fuse pins,
    2. Replacement of cracked straight fuse pins with either new 15-5PH 
corrosion- resistant steel fuse pins or like pins,
    3. Replacement of bulkhead fuse pins with new 15-5PH corrosion-
resistant steel fuse pins, and
    4. Repetitive inspections of newly-installed fuse pins. 
(Installation of the new 15-5PH corrosion-resistant steel fuse pins 
would allow a longer repetitive inspection interval than was previously 
provided by AD 93-16-09.)
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    All of the commenters support the proposed rule.
    One of the commenters, however, requests that the FAA consider 
revising this AD to include terminating action when Boeing finalizes 
its proposed pylon modification program. The commenter considers that 
that program, together with the replacement of the fuse pins, should 
constitute terminating action for the repetitive inspections that are 
required by this AD. The FAA acknowledges this comment, and may 
consider additional rulemaking once the manufacturer's pylon 
modification program has been developed, reviewed, and approved.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.
    There are approximately 273 Model 757 series airplanes equipped 
with Pratt & Whitney engines of the affected design in the worldwide 
fleet. The FAA estimates that 237 airplanes of U.S. registry will be 
affected by this AD.
    The actions that are currently required by AD 93-16-09 take 
approximately 8 work hours per fuse pin; there are 4 fuse pins per 
airplane. The average labor rate is approximately $60 per work hour. 
Based on these figures, the cost impact of the actions currently 
required by AD 93-16-09 on U.S. operators is estimated to be $455,040, 
or $1,920 per airplane, per cycle. However, since the integrity and 
strength of the new steel fuse pins permit longer inspection intervals, 
the cost impact for these inspections will actually be lessened (since 
the inspections are not required to be performed as frequently as they 
were previously required under AD 93-16-09).
    The new actions that are required by this new AD will take 
approximately 56 work hours per fuse pin to accomplish, at an average 
labor rate of $60 per work hour (There are 4 fuse pins per airplane). 
Required parts will be provided by the manufacturer at no cost to the 
operator. Based on these figures, the cost impact on U.S. operators of 
the new requirements of this AD is estimated to be $3,185,280, or 
$13,440 per airplane.
    The cost impact figures discussed above are 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 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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-8666 (58 FR 
45044, August 26, 1993), and by adding a new airworthiness directive 
(AD), amendment 39-9533, to read as follows:

96-05-07 Boeing: Amendment 39-9533. Docket 94-NM-72-AD. Supersedes 
AD 93-16-09, Amendment 39-8666.

    Applicability: Model 757 series airplanes equipped with Pratt & 
Whitney engines, 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 (f) 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.
    Note 2: Inspections accomplished prior to the effective date of 
this amendment in accordance with the procedures described in Boeing 
Service Bulletin 757-54A0019, Revision 4, dated May 27, 1993; 
Revision 3, dated March 26, 1992; or Revision 2, dated October 11, 
1989; are considered acceptable for compliance with the applicable 
inspection specified in this amendment.

    To prevent cracking of the midspar fuse pins, which may lead to 
separation of the strut and engine from the wing of the airplane, 
accomplish the following:
    (a) For airplanes equipped with straight fuse pins, part number 
(P/N) 311N5067-1: Prior to the accumulation of 3,800 total flight 
cycles on the straight fuse pin, perform an eddy current inspection 
to detect cracking in the straight fuse pins, in accordance with 
Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 
1994.
    (1) If no cracking is detected, repeat the inspection thereafter 
at intervals not to 

[[Page 9601]]
exceed 1,000 flight cycles on the straight fuse pin.
    (2) If any cracking is detected, prior to further flight, 
accomplish the requirements of either paragraph (a)(2)(i) or 
(a)(2)(ii) of this AD.
    (i) Replace the cracked straight fuse pin with a new straight 
fuse pin, P/N 311N5067-1. Prior to the accumulation of 3,800 total 
flight cycles on that newly installed straight fuse pin, perform an 
eddy current inspection to detect cracking in that straight fuse 
pin, in accordance with the service bulletin. Repeat the inspection 
thereafter at intervals not to exceed 1,000 flight cycles on that 
newly installed straight fuse pin. Or
    (ii) Replace the cracked straight fuse pin with a new 15-5PH 
fuse pin, P/N 311N5217-1. Prior to the accumulation of 14,000 total 
flight cycles on that newly installed 15-5PH fuse pin, perform an 
eddy current inspection to detect cracking in that newly installed 
15-5PH fuse pin, in accordance with the procedures described in the 
service bulletin. Repeat the inspection thereafter at intervals not 
to exceed 3,500 flight cycles on that newly installed 15-5PH fuse 
pin.
    (b) For airplanes equipped with refinished straight fuse pins, 
P/N 311N5067-1: Prior to the accumulation of 1,000 total flight 
cycles on the refinished straight fuse pin, perform an eddy current 
inspection to detect cracking in the refinished straight fuse pins, 
in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, 
dated March 17, 1994.
    (1) If no cracking is detected, repeat the inspection thereafter 
at intervals not to exceed 1,000 flight cycles on the refinished 
straight fuse pin.
    (2) If any cracking is detected, prior to further flight, 
accomplish the requirements of either paragraph (b)(2)(i), 
(b)(2)(ii), or (b)(2)(iii) of this AD, in accordance with the 
service bulletin.
    (i) Replace the cracked refinished straight fuse pin with a 
crack-free refinished straight fuse pin, P/N 311N5067-1. Prior to 
the accumulation of 1,000 total flight cycles on that newly 
installed refinished straight fuse pin, perform an eddy current 
inspection to detect cracking in that newly installed refinished 
straight fuse pin, in accordance with the procedures described in 
the service bulletin. Repeat this inspection thereafter at intervals 
not to exceed 1,000 flight cycles on the newly installed refinished 
straight fuse pin. Or
    (ii) Replace the cracked refinished straight fuse pin with a new 
straight fuse pin, P/N 311N5067-1. Prior to the accumulation of 
3,800 total flight cycles on that newly installed straight fuse pin, 
perform an eddy current inspection to detect cracking in that newly 
installed straight fuse pin, in accordance with the service 
bulletin. Repeat the inspection thereafter at intervals not to 
exceed 1,000 flight cycles on that newly installed straight fuse 
pin. Or
    (iii) Replace the cracked refinished straight fuse pin with a 
new 15-5PH fuse pin, P/N 311N5217-1. Prior to the accumulation of 
14,000 total flight cycles on that newly installed 15-5PH fuse pin, 
perform an eddy current inspection to detect cracking in that newly 
installed 15-5PH pin, in accordance with the procedures described in 
the service bulletin. Repeat the inspection thereafter at intervals 
not to exceed 3,500 flight cycles on that newly installed 15-5PH 
fuse pin.
    (c) For airplanes equipped with bulkhead fuse pins, P/N 
311N5211-1: Within 3,000 flight cycles after the effective date of 
this AD, replace the bulkhead fuse pins with 15-5PH fuse pins, P/N 
311N5217-1, in accordance with Boeing Service Bulletin 757-54A0019, 
Revision 5, dated March 17, 1994, and accomplish the requirements of 
paragraph (d) of this AD.
    (d) For airplanes equipped with 15-5PH fuse pins: Prior to the 
accumulation of 14,000 total flight cycles on the 15-5PH fuse pins, 
perform an eddy current inspection to detect cracking in those 15-
5PH fuse pins, in accordance with the procedures described in Boeing 
Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994.
    (1) If no cracking is detected, repeat the inspection thereafter 
at intervals not to exceed 3,500 flight cycles on the 15-5PH fuse 
pin.
    (2) If any cracking is detected, accomplish the requirements of 
both paragraphs (d)(2)(i) and (d)(2)(ii) of this AD.
    (i) Prior to further flight, replace any cracked 15-5PH fuse pin 
with a new 15-5PH fuse pin, P/N 311N5217-1, in accordance with the 
procedures described in the service bulletin. And
    (ii) Prior to the accumulation of 14,000 total flight cycles on 
that newly installed 15-5PH fuse pin, perform an eddy current 
inspection to detect cracking in that newly installed 15-5PH fuse 
pin, in accordance with the procedures described in the service 
bulletin. Repeat the inspection thereafter at intervals not to 
exceed 3,500 flight cycles on that newly installed 15-5PH fuse pin.
    (e) Fuse pins must be of the same type on the same strut. For 
example, a steel fuse pin having P/N 311N5067-1 may not be installed 
on the same strut that has a corrosion-resistant steel (CRES) fuse 
pin having P/N 311N5217-1 installed on that strut. However, fuse 
pins on one strut may differ from those on another strut, provided 
the fuse pins are not of mixed types on the same strut.
    (f) 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, Seattle Aircraft Certification 
Office (ACO), 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, Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (g) 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.
    (h) The inspections and replacements shall be done in accordance 
with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 
17, 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 Boeing Commercial 
Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. 
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.
    (i) This amendment becomes effective on April 10, 1996.

    Issued in Renton, Washington, on March 1, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-5369 Filed 3-8-96; 8:45 am]
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