[Federal Register Volume 66, Number 78 (Monday, April 23, 2001)]
[Rules and Regulations]
[Pages 20380-20383]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-9664]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2000-NM-295-AD; Amendment 39-12184; AD 2001-08-07]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-200 and -300 Series
Airplanes Equipped with a Main Deck Cargo Door Installed in Accordance
with Supplemental Type Certificate (STC) SA2969SO
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 737-200 and -300 series
airplanes, that currently requires a one-time inspection to detect
cracks of the lower frames and reinforcing angles of the main deck
cargo door where the door latch fittings attach between certain
fuselage stations and water lines, and replacement of any cracked part
with a new part having the same part number. That AD was prompted by
reports that, during the inspections required by the existing AD,
cracks were found in the reinforcing angles of the main deck cargo door
frame. This amendment requires, among other actions, an inspection to
detect cracks of the lower frames and
[[Page 20381]]
reinforcing angles of the main deck cargo door; replacement of any
lower frame or reinforcing angle of the main deck cargo door when it
has reached its maximum life limit. The actions specified by this AD
are intended to detect and correct cracking of the lower portion of the
main deck cargo door frames, which could result in sudden
depressurization, loss or opening of the main deck cargo door during
flight, and loss of control of the airplane.
DATES: Effective May 29, 2001.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of May 29, 2001.
ADDRESSES: The service information referenced in this AD may be
obtained from Pemco World Air Services, 100 Pemco Drive, Dothan, AL
36303. 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, Atlanta
Aircraft Certification Office, One Crown Center, 1895 Phoenix
Boulevard, Suite 450, Atlanta, Georgia; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: William Culler, Aerospace Engineer,
Airframe and Propulsion Branch, ACE-117A, FAA, Atlanta Aircraft
Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite
450, Atlanta, Georgia 30337-2748, telephone (770) 703-6084; fax (770)
703-6097.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 2000-17-51,
amendment 39-11877 (65 FR 51752, August 25, 2000), which is applicable
to certain Boeing Model 737-200 and -300 series airplanes, was
published in the Federal Register on October 17, 2000 (65 FR 61289).
The action proposed to require, among other actions, an inspection to
detect cracks of the lower frames and reinforcing angles of the main
deck cargo door; replacement of any lower frame or reinforcing angle of
the main deck cargo door when it has reached its maximum life limit.
Comments Received
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request to Change Proposed High Frequency Eddy Current (HFEC)
Inspections to Detailed Visual Inspections
One commenter requests that, in lieu of the proposed repetitive
HFEC inspections, repetitive detailed visual inspections with a
borescope, flexiscope, or mirror and light be required every 600 flight
cycles for cracks in the frames and, especially, in the reinforcing
angles, provided that the initial inspection was an HFEC inspection of
all lower frames and angles and all parts with crack indication were
replaced with new parts. The commenter states that this change would
alleviate the need to remove and reinstall the necessary hardware
required to perform an adequate HFEC inspection, which causes an
extended fleet downtime and damages the area being inspected. The
commenter also states that it has reviewed statistical data from its
fleet of airplanes on which HFEC inspections were done per AD 2000-17-
51 that shows the number of cracked angles is higher than the number of
cracked frames at the same frame station. Based on this data, the
commenter provided a graph that shows a close correlation between
cracked frames and attached angles.
The FAA does not agree. As indicated in the preamble of AD 2000-17-
51, the special detailed visual inspection done per AD 2000-13-51 is
not adequate to detect cracks embedded behind the reinforcing angles.
In addition, previous reports from the commenter's fleet, and other
operators, indicate that cracks could exist on a frame and remain
hidden behind uncracked reinforcing angles. Therefore, we find that the
required repetitive HFEC inspections are warranted to address the
identified unsafe condition.
Request to Revise Wording of Paragraph (b)(2) of the Proposed AD
One commenter requests that paragraph (b)(2) of the proposed AD be
revised to ``* * * replace the frames and associated angles which were
not changed as per AD 2000-17-51 * * * Within 3,000 flight cycles after
accomplishment of the replacement of parts as per 2000-NM-295-AD, do
the HFEC inspection required of all the frames and associated angles.''
The commenter states that revising ``reinforcing angle'' to
``associated angle'' is necessary, because the terminating action,
which is being developed, relies on a new angle (reinforcing angle)
located on top of the existing angle (associated angle of the frame).
The FAA does not agree. We find that adding the phrase ``which were
not changed per AD 2000-17-51'' is unnecessary, because paragraph (b)
of the final rule clearly identifies the affected airplanes as those
``on which any door frame or reinforcing angle at the location where
the door latch fittings attach between FS 361.86 and FS 298.12 and WL
202.35 and WL 213.00 has NOT been replaced before the effective date of
this AD.'' In addition, the header of paragraph (b) of the final rule
is ``Actions Addressing Door Frames or Reinforcing Angles That Have NOT
Been Replaced.'' We also find that adding the phrase ``as per 2000-NM-
295-AD'' to the compliance time of ``within 3,000 flight cycles after
accomplishment of the replacement'' is unnecessary and redundant as the
``Compliance'' section of this AD states, ``Required as indicated,
unless previously accomplished.'' We note that the docket number
associated with the preceding NPRM and this final rule is 2000-NM-295-
AD. Furthermore, the term ``reinforcing angle'' is used in the design
data and service documents of the original equipment manufacturer and
in preceding AD's. Therefore, based on these conclusions, we find that
no change is necessary to paragraph (b)(2) of the final rule.
Requests to Reference or Develop Terminating Action
One commenter requests that the airplane manufacturer develop a
terminating modification for the repetitive inspections required by the
proposed AD. A second commenter requests that the proposed AD reference
Pemco Service Bulletin 737-52-0036 as terminating action for the
repetitive requirements of the proposed AD. A third commenter, Pemco,
states that it is currently developing two terminating actions, and
that they will be approved by a Designated Engineering Representative
in November and December 2000. One commenter states that the proposed
repetitive inspections requires removal and reinstallation of hardware,
which can reduce fastener edge distance and potentially cause damage to
the inspected areas. The commenter also states that these inspections
cause unscheduled downtimes up to four weeks per airplane.
The FAA agrees with the commenters that a terminating action is
desireable. However, we do not agree with the commenters' concern that
the required inspections and reinstallation of hardware may result in
potential
[[Page 20382]]
damage to the inspected area, since we anticipate that the terminating
action will be available before the accomplishment of multiple
inspections. We are aware that the affected Supplemental Type
Certificate (STC) holder is developing service bulletin procedures to
address the identified unsafe condition. However, the service bulletins
are not scheduled to be completed until mid 2001. We have decided not
to delay this action in anticipation of the service bulletins, since
the release date is not absolute and this action is necessary to
address an identified unsafe condition. Therefore, the FAA may approve
requests for an alternative method of compliance (AMOC) under the
provisions of paragraph (c) of this AD once the revised bulletins are
issued. No change to the final rule is necessary.
Conclusion
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.
Cost Impact
There are approximately 35 Model 737-200 and -300 series airplanes
of the affected design in the worldwide fleet. The FAA estimates that 2
airplanes of U.S. registry will be affected by this AD.
It will take approximately 500 work hours per airplane to
accomplish the inspection, at an average labor rate of $60 per work
hour. Based on these figures, the cost impact of the inspection
required by this AD on U.S. operators is estimated to be $60,000, or
$30,000 per airplane.
It will take approximately 128 work hours per airplane to
accomplish the replacement, at an average labor rate of $60 per work
hour. Required parts will cost approximately $15,521 per airplane.
Based on these figures, the cost impact of the replacement required by
this AD on U.S. operators is estimated to be $46,402, or $23,201 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 cost impact figures discussed
in AD rulemaking actions represent only the time necessary to perform
the specific actions actually required by the AD. These figures
typically do not include incidental costs, such as the time required to
gain access and close up, planning time, or time necessitated by other
administrative actions.
Regulatory Impact
The regulations adopted herein will not have a substantial direct
effect 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, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
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 removing amendment 39-11877 (65 FR
51752, August 25, 2000), and by adding a new airworthiness directive
(AD), amendment 39-12184, to read as follows:
2001-08-07 Boeing: Amendment 39-12184. Docket 2000-NM-295-AD.
Supersedes AD 2000-17-51, Amendment 39-11877.
Applicability: Model 737-200 and -300 series airplanes, equipped
with a main deck cargo door installed in accordance with
Supplemental Type Certificate (STC) SA2969SO; 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)(1)
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 detect and correct cracking of the lower portion of the main
deck cargo door frames, which could result in sudden
depressurization, loss or opening of the main deck cargo door during
flight, and loss of control of the airplane, accomplish the
following:
Actions Addressing Door Frames or Reinforcing Angles That Have Been
Replaced
(a) For airplanes on which any door frame or reinforcing angle
at the location where the door latch fittings attach between
fuselage station (FS) 361.86 and FS 298.12 and water line (WL)
202.35 and WL 213.00 has been replaced before the effective date of
this AD: Do the actions specified in paragraphs (a)(1) and (a)(2) of
this AD per the Accomplishment Instructions of Pemco Service
Bulletin 737-52-0037, Revision 2, dated September 13, 2000,
including Attachment 1, dated August 10, 2000.
(1) Within 3,000 flight cycles after accomplishment of the
replacement, do a high frequency eddy current (HFEC) inspection to
detect cracks of the replaced lower frames or replaced reinforcing
angles of the main deck cargo door, as applicable.
(i) If no crack is detected, repeat the HFEC inspection
thereafter at intervals of 1,300 flight cycles on the replaced part.
(ii) If any crack is detected, before further flight, replace
the cracked part with a new part having the same part number per the
service bulletin. Within 3,000 flight cycles after accomplishment of
the replacement, do the HFEC inspection required by paragraph (a)(1)
of this AD.
(2) Before or upon the accumulation of 7,000 total flight cycles
on any lower frame or reinforcing angle of the main deck cargo door,
replace the lower frame or reinforcing angle, as applicable, with
new parts. Within 3,000 flight cycles after accomplishment of the
replacement, do the HFEC inspection required by paragraph (a)(1) of
this AD.
Actions Addressing Door Frames or Reinforcing Angles That Have NOT Been
Replaced
(b) For airplanes on which any door frame or reinforcing angle
at the location where the door latch fittings attach between FS
361.86 and FS 298.12 and WL 202.35 and WL 213.00 has NOT been
replaced before the effective date of this AD: Within 1,300 flight
cycles after accomplishment of the HFEC inspection required by AD
2000-17-51, amendment 39-11877, do the action specified in either
paragraph (b)(1) or (b)(2) of this AD, as applicable, per the
Accomplishment
[[Page 20383]]
Instructions of Pemco Service Bulletin 737-52-0037, Revision 2,
dated September 13, 2000, including Attachment 1, dated August 10,
2000.
(1) For airplanes that have accumulated less than 7,000 total
flight cycles since installation of STC SA2969SO: Do an HFEC
inspection to detect cracks of the lower frames and reinforcing
angles of the main deck cargo door where the door latch fittings
attach between FS 361.87 and FS 498.12 and WL 202.35 and WL 213.00.
(i) If no crack is detected, do the actions specified in
paragraphs (b)(1)(i)(A) and (b)(1)(i)(B) of this AD.
(A) Repeat the HFEC inspection thereafter at intervals of 1,300
flight cycles on the airplane, but not to exceed the accumulation of
7,000 total flight cycles on the airplane.
(B) Before the accumulation of 7,000 total flight cycles on the
airplane, replace the lower frame and reinforcing angle with new
parts per the service bulletin. Within 3,000 flight cycles after
accomplishment of the replacement, do the HFEC inspection required
by paragraph (a)(1) of this AD.
(ii) If any crack is detected, before further flight, replace
the cracked part with a new part having the same part number per the
service bulletin. Within 3,000 flight cycles after accomplishment of
the replacement, do the HFEC inspection required by paragraph (a)(1)
of this AD.
(2) For airplanes that have accumulated 7,000 or more total
flight cycles since installation of STC SA2969SO: Replace the lower
frames and reinforcing angles with new parts. Within 3,000 flight
cycles after accomplishment of the replacement, do the HFEC
inspection required by paragraph (a)(1) of this AD.
Alternative Methods of Compliance
(c)(1) 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, Atlanta Aircraft Certification
Office (ACO), FAA. Operators shall submit their requests through an
appropriate FAA Principal Maintenance Inspector, who may add
comments and then send it to the Manager, Atlanta ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
(2) Alternative methods of compliance, approved previously in
accordance with AD 2000-17-51, amendment 39-11877, are approved as
alternative methods of compliance with the initial HFEC inspection
required by paragraph (a)(1) of this AD.
Special Flight Permits
(d) Special flight permits may be issued in accordance with
Secs. 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.
Incorporation by Reference
(e) The actions shall be done in accordance with Pemco Service
Bulletin 737-52-0037, Revision 2, dated September 13, 2000,
including Attachment 1, dated August 10, 2000, which contains the
list of effective pages specified in Table 1 of this AD. Table 1 is
as follows:
Table 1.
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Revision level
Page number shown on page Date shown on page
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1............................... A................. August 15, 2000.
2, 3, 6-10...................... Original.......... August 10, 2000.
4, 4a, 5........................ 2................. September 13,
2000.
Attachment 1, 2................. Original.......... August 10, 2000.
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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 Pemco World Air Services, 100
Pemco Drive, Dothan, AL 36303. Copies may be inspected at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the FAA, Atlanta Aircraft Certification Office,
One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta,
Georgia; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
Effective Date
(f) This amendment becomes effective on May 29, 2001.
Issued in Renton, Washington, on April 12, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 01-9664 Filed 4-20-01; 8:45 am]
BILLING CODE 4910-13-U