[Federal Register Volume 68, Number 235 (Monday, December 8, 2003)]
[Proposed Rules]
[Pages 68301-68304]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-30334]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-90-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes. This proposal would 
require repetitive inspections for corrosion and cracking of the pivot 
hinge pins of the horizontal stabilizer, certain follow-on inspections, 
and replacement of the hinge pins with new or serviceable pins if 
necessary. This action is necessary to prevent failure of the outer and 
inner hinge pins due to corrosion or cracking, which could allow the 
pins to migrate out of the joint and result in intermittent movement of 
the horizontal stabilizer structure and consequent loss of 
controllability of the airplane. This action is intended to address the 
identified unsafe condition.

DATES: Comments must be received by January 22, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-90-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2003-NM-90-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 or 2000 or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6440; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the Alert 
Service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2003-NM-90-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2003-NM-90-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of corrosion in the pivot hinge pins 
that attach the horizontal stabilizer center section to the Body 
Station 1156 support bulkhead on certain Boeing Model 737-300, -400, 
and -500 series airplanes. Corrosion has been found on outer primary 
pins and inner failsafe pins made from both 4330 steel and 15-5 PH 
corrosion-resistant steel (CRES). Investigation has revealed the 
presence of heavy corrosion on areas of the outer pin not protected by 
chrome plating and of heavy corrosion on all areas of the inner pin. 
Such corrosion or cracking could lead to pin failure and allow the pins 
to migrate out of the joint, resulting in intermittent movement of the 
horizontal stabilizer structure and consequent loss of controllability 
of the airplane.

Similar Airplanes

    The pivot hinge pins of the horizontal stabilizer on certain Boeing 
Model 737-100, -200, and 200C series airplanes are identical to those 
on the affected Model 737-300, -400, and -500 series airplanes. 
Therefore, all of these models may be subject to the same unsafe 
condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-55A1077, dated December 6, 2001, which describes procedures for 
performing repetitive detailed and magnetic particle inspections for 
corrosion and cracking of the hinge pin joints of the horizontal 
stabilizer. The alert service bulletin also describes procedures for 
replacing the hinge pins with new or serviceable pins if necessary. 
Accomplishment of the actions specified in the alert service bulletin 
is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the alert service bulletin described previously, except as discussed 
below.

[[Page 68302]]

Differences Between the Proposed Rule and the Alert Service Bulletin

    Where the Accomplishment Instructions of the alert service bulletin 
specify a certain area of inspection of the outer pin as area that 
``includes the tapered shank, the adjacent thread relief radius, and 
the threaded end, * * *,'' this AD specifies the area that ``includes 
the tapered shank, the adjacent thread relief radius, or the threaded 
end, * * * .'' Additionally, where the Accomplishment Instructions of 
the alert service bulletin specify a certain other area of inspection 
of the outer pin as area that `` includes the straight shank and the 
head, * * * ,'' this AD specifies the area that ``includes the straight 
shank or the head, * * * '' The manufacturer has advised us that it has 
notified opertors of its intention to revise the referenced alert 
service bulletin to reflect these corrections.
    Although the alert service bulletin specifies that operators should 
contact the manufacturer for disposition of certain corrosion 
conditions, this proposed AD would require operators to repair those 
conditions per a method approved by the FAA.

Changes to 14 CFR Part 39/Effect on the Proposed AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance (AMOCs). Because we have now included this material in part 
39, only the office authorized to approve AMOCs is identified in each 
individual AD.

Change to Labor Rate Estimate

    We have reviewed the figures we have used over the past several 
years to calculate AD costs to operators. To account for various 
inflationary costs in the airline industry, we find it necessary to 
increase the labor rate used in these calculations from $60 per work 
hour to $65 per work hour. The cost impact information, below, reflects 
this increase in the specified hourly labor rate.

Cost Impact

    There are approximately 3,132 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,250 airplanes of U.S. 
registry would be affected by this proposed AD.
    We estimate that it would take approximately 1 work hour per 
airplane to accomplish the detailed inspection specified in paragraph 
(a) of the proposed AD, and that the average labor rate is $65 per work 
hour. Since the requirements of paragraph (a) of this proposed AD apply 
to the total affected fleet, the cost impact of the inspections 
required by paragraph (a) of this proposed AD on U.S. operators is 
estimated to be $81,250, or $65 per airplane, per inspection cycle.
    It would take approximately 6 work hours per airplane, per 
inspection, to accomplish the detailed and magnetic particle 
inspections described in Part 2 of the Accomplishment Instructions of 
the specified alert service bulletin. We estimate that if all airplanes 
were required to accomplish those inspections, the estimated cost 
impact of the affected airplanes would be $487,500 or $390 airplane, 
per inspection cycle.
    It would take approximately 12 work hours per airplane, per 
inspection, to accomplish the detailed and magnetic particle 
inspections described in Part 3 of the Accomplishment Instructions of 
the specified alert service bulletin. We estimate that if all airplanes 
were required to accomplish those inspections, the estimated cost 
impact of the affected airplanes would be $975,000, or $780 per 
airplane, per inspection cycle.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this proposed 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 proposed herein would 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 proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Boeing: Docket 2003-NM-90-AD.


    Applicability: Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes having line numbers 1 through 3132 inclusive; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the outer and inner pivot hinge pins due 
to corrosion or cracking, which could allow the pins to migrate out 
of the joint and result in intermittent movement of the horizontal 
stabilizer structure and consequent loss of controllability of the 
airplane; accomplish the following:
    (a) For all airplanes: Within 90 days after the effective date 
of this AD, perform a detailed inspection of the pivot hinge pin 
joints for corrosion and, with hand pressure, check for movement of 
the hinge pins within the joints of the horizontal stabilizer, per 
Part 1 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-55A1077, dated December 6, 2001. Repeat the detailed 
inspections and check at intervals not to exceed 180 days until the 
initial inspection specified in paragraph (b), (d), (f), or (h) of 
this AD, as applicable, is performed.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''


[[Page 68303]]


    (1) If no corrosion is found, and if the hinge pins cannot be 
moved with hand pressure, the hinge pins are serviceable. No further 
action is required by this paragraph.
    (2) If any pin can be moved with hand pressure, before further 
flight, remove and inspect both pins and perform follow-on 
corrective actions per Part 3 of the Accomplishment Instructions of 
the alert service bulletin.
    (3) If any corrosion is found, before further flight, remove and 
perform a detailed inspection of the pin(s) per Figure 2 (inner pin) 
or Figure 3 (inner and outer pins), as applicable, of the 
Accomplishment Instructions of the Alert Service Bulletin; and 
perform follow-on corrective actions, per the Accomplishment 
Instructions of the alert service bulletin.
    (b) For Models 737-100, -200, and 200C series airplanes: Within 
3,000 flight hours or 24 months after the effective date of this AD, 
whichever occurs first, perform a detailed inspection and magnetic 
particle inspection for corrosion and cracking of the horizontal 
stabilizer hinge pins, per Part 2 of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-55A1077, dated December 6, 
2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (b)(3) 
and (b)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is damage free, before further flight, 
replace the outer pin with a new or serviceable pin, per the 
Accomplishment Instructions of the alert service bulletin.
    (3) If an outer pin is cracked in the area that includes the 
straight shank or the head, before further flight, replace both the 
inner and outer pins with new or serviceable pins, per the 
Accomplishment Instructions of the alert service bulletin.
    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pins with new or 
serviceable pins, per the Accomplishment Instructions of the alert 
service bulletin.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin, per the 
Accomplishment Instructions of the alert service bulletin.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, repair per a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA.
    (c) For Models 737-100, -200, -200C series airplanes: 
Thereafter, repeat the inspections required by paragraph (b) of this 
AD at the times specified in paragraph (c)(1) or (c)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, repeat the 
inspection at intervals not to exceed 6,000 flight hours or 48 
months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
grease (Mastinox 6856K), repeat the inspections at intervals not to 
exceed 3,000 flight hours or 24 months, whichever occurs first.
    (d) For Models 737-100, -200, and -200C series airplanes: Within 
12,000 flight hours or 96 months after the effective date of this 
AD, whichever occurs first, perform a detailed inspection and 
magnetic particle inspection for corrosion and cracking of the 
horizontal stabilizer hinge pins, per Part 3 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-55A1077, dated 
December 6, 2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (d)(3) 
and (d)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is damage free, before further flight, 
replace the outer pin with a new or serviceable pin, per the 
Accomplishment Instructions of the alert service bulletin.
    (3) If an outer pin is cracked in the area that includes the 
straight shank and the head, before further flight, replace both the 
inner and outer pins with new or serviceable pins, per the 
Accomplishment Instructions of the alert service bulletin.
    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pins with new or 
serviceable pins, per the Accomplishment Instructions of the alert 
service bulletin.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin, per the 
Accomplishment Instructions of the alert service bulletin.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, repair per a method approved by the Manager, Seattle 
ACO.
    (e) For Models 737-100, -200, -200C series airplanes: 
Thereafter, repeat the inspections required by paragraph (d) of this 
AD at the times specified in paragraph (e)(1) or (e)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, thereafter, 
repeat the inspections at intervals not to exceed 12,000 flight 
hours or 96 months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
grease (Mastinox 6856K), thereafter, repeat the inspections at 
intervals not to exceed 6,000 flight hours or 48 months, whichever 
occurs first.
    (f) For Model 737-300, -400, and -500 series airplanes: Within 
4,000 flight hours or 24 months from the effective date of this AD, 
whichever occurs first, inspect the horizontal stabilizer hinge 
pins, per Part 2 of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-55A1077, dated December 6, 2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (f)(3) 
and (f)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is damage free, before further flight, 
replace the outer pin with a new or serviceable pin, per the 
Accomplishment Instructions of the alert service bulletin.
    (3) If an outer pin is cracked in the area that includes the 
straight shank or the head, before further flight, replace both the 
inner and outer pins with new or serviceable pins, per the 
Accomplishment Instructions of the alert service bulletin.
    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pins with new or 
serviceable pins, per the Accomplishment Instructions of the alert 
service bulletin.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin, per the 
Accomplishment Instructions of the alert service bulletin.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, repair per a method approved by the Manager, Seattle 
ACO.
    (g) For Model 737-300, -400, and -500 series airplanes: 
Thereafter, repeat the inspections required by paragraph (f) of this 
AD at the times specified in paragraph (g)(1) or (g)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, therafter, 
repeat the inspections at intervals not to exceed 8,000 flight hours 
or 48 months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
(Mastinox 6856K), repeat the inspections at intervals not to exceed 
4,000 flight hours or 24 months, whichever occurs first.
    (h) For Model 737-300, -400, and -500 series airplanes: Within 
16,000 flight hours or 96 months from the effective date of this AD, 
whichever occurs first, perform a detailed inspection and magnetic 
particle inspection for corrosion or cracking of the horizontal 
stabilizer hinge pins per Part 3 of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-55A1077, dated December 6, 
2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (h)(3) 
and (h)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is damage free, before further flight, 
replace the outer pin with a new or serviceable pin.
    (3) If an outer pin is cracked in the area that includes the 
straight shank or the head, before further flight, replace both the 
inner and outer pin with new or serviceable pins.
    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pin with new or serviceable 
pins.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, contact the Manager, Seattle ACO.

[[Page 68304]]

    (i) For Model 737-300, -400, and -500 series airplanes: 
Thereafter, repeat the inspections required by paragraph (h) of this 
AD at the times specified in paragraph (i)(1) or (i)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, thereafter, 
repeat the inspections at intervals not to exceed 16,000 flight 
hours or 96 months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
(Mastinox 6856K), thereafter, repeat the inspections at intervals 
not to exceed 8,000 flight hours or 48 months, whichever occurs 
first.

Alternative Methods of Compliance

    (j) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, 
FAA, is authorized to approve alternative methods of compliance for 
this AD.

    Issued in Renton, Washington, on December 1, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-30334 Filed 12-5-03; 8:45 am]
BILLING CODE 4910-13-P