[Federal Register Volume 62, Number 155 (Tuesday, August 12, 1997)]
[Rules and Regulations]
[Pages 43067-43069]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-20952]



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Rules and Regulations
                                                Federal Register
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Federal Register / Vol. 62, No. 155 / Tuesday, August 12, 1997 / 
Rules and Regulations

[[Page 43067]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-152-AD; Amendment 39-10102; AD 97-17-01]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100 and -200 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 all Boeing Model 737-100 and -200 series airplanes, that 
requires replacement of certain outboard and inboard wheel halves with 
improved wheel halves. This amendment also requires cleaning and 
inspecting certain outboard and inboard wheel halves for corrosion, 
missing paint in large areas, and cracks; and repair or replacement of 
the wheel halves with serviceable wheel halves, if necessary. This 
amendment is prompted by a review of the design of the flight control 
systems on Model 737 series airplanes. The actions specified by this AD 
are intended to prevent failure of the wheel flanges, which could 
result in damage to the hydraulics systems, jammed flight controls, 
loss of electrical power, or other combinations of failures; and 
consequent reduced controllability of the airplane.

DATES: Effective September 16, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 16, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Allied Signal Aerospace Company, Bendix Wheels and Brakes 
Division, South Bend, Indiana 46624; and Bendix, Aircraft Brake and 
Strut Division, 3520 Westmoor Street, South Bend, Indiana 46628-1373. 
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: David Herron, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2672; fax (425) 
227-1181.

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 Boeing Model 737-100 and -200 
series airplanes was published in the Federal Register as a 
supplemental notice of proposed rulemaking (NPRM) on March 14, 1997 (62 
FR 12123). That action proposed to require replacement of certain 
outboard and inboard wheel halves with improved wheel halves. That 
action also proposed to require cleaning and inspecting certain 
outboard and inboard wheel halves for corrosion, missing paint in large 
areas, and cracks; and repair or replacement of the wheel halves with 
serviceable wheel halves, if necessary.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    Two commenters support the proposed rule.

Request To Withdraw the Proposal

    One commenter states that review of the design of the flight 
control systems on Model 737 series airplanes occurred on a military 
aircraft, yet military airplanes are often subjected to harsh operating 
environments and possibly operate with a lower level of inspection than 
is found in commercial aviation. The commenter states that the existing 
inspection schedules and inspection techniques in accordance with the 
latest manufacturer's recommendations are adequate to prevent an unsafe 
condition. The FAA infers from these remarks that the commenter 
requests the proposed supplemental NPRM be withdrawn.
    The FAA does not concur with the request to withdraw the 
supplemental NPRM.
    The FAA did not propose rulemaking for the subject unsafe condition 
based solely on a single event. The FAA review of available service 
information and the close proximity to the wheels of certain types of 
equipment were contributing factors in the FAA's finding of the subject 
unsafe condition. Furthermore, the commenter did not provide any 
evidence to support its statement that military airplanes may have a 
lower level of inspection than is found in commercial aviation, nor did 
the commenter provide any substantiation for the statement that 
existing inspections schedules and techniques are adequate to prevent 
an unsafe condition.

Request to Remove Certain Airplanes From Applicability

    One commenter, an operator, stated that its airplanes are equipped 
with BF Goodrich main wheels rather than Bendix wheels. The FAA infers 
that the operator requests that its airplanes be removed from the 
applicability of this rule.
    The FAA concurs that airplanes equipped with other than Bendix 
wheels are not subject to the requirements of this rule. Since the 
applicability of this rule clearly states that it applies only to 
airplanes equipped with Bendix wheels, the FAA finds that no change to 
the final rule is necessary.

Request To Correct Serial Numbers of the Wheel Halves

    One commenter, the wheel half manufacturer, requests that the 
serial numbers of the inboard wheel halves be revised based on its 
further research into the manufacturing records of the wheel halves. 
The manufacturer advises that the revised serial numbers reflect the 
elimination of certain serial numbers of the wheel halves that have 
been ``beefed up;'' therefore, those certain serial numbers do not need 
to be replaced. The manufacturer contends that the correction of the 
serial numbers will provide an economic benefit to operators as the 
pool of useable wheel

[[Page 43068]]

halves would potentially be increased by 179 for inboard halves and 236 
for outboard halves. The wheel half manufacturer also states that it 
has issued Allied Signal, Aircraft Landing Systems, Service Information 
Letter (SIL) #619, dated February 26, 1997, that corrects the serial 
numbers. Specifically, the commenter requests that:
    <bullet> Paragraph (a) of the proposal be revised to read ``* * * 
with an inboard wheel half with serial number (S/N) B-5898 or lower, or 
S/N H-1721 or lower; or with an outboard wheel half with S/N B-5898 or 
lower, or S/N H-0863 or lower * * *''
    <bullet> Paragraph (b) of the proposal be revised to read ``* * * 
with an inboard wheel half with S/N B-5898 or lower, or S/N H-1721 or 
lower; or with an outboard wheel half with S/N B-5898 or lower, or S/N 
H-0863 or lower * * *''
    <bullet> Paragraph (b)(1) of the proposal be revised to read ``* * 
* and replace it with an inboard wheel half having part number (P/N) 
2607046, S/N 5899 or greater, or S/N H-1722 or greater.''
    <bullet> Paragraph (b)(2) of the proposal be revised to read ``* * 
* and replace it with an outboard wheel half having P/N 2607047, S/N B-
5899 or greater, or S/N H-0864 or greater.''
    The FAA concurs with the revision of the serial numbers based on 
the commenter's justification. The final rule has been revised as 
suggested by the commenter.
    Additionally, the FAA has added a new ``Note 2'' to this final rule 
to reference the SIL discussed by the commenter as an additional source 
of service information concerning appropriate wheel half serial 
numbers.

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 with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 634 Boeing Model 737-100 and -200 series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 241 airplanes of U.S. registry will be affected by this 
AD.
    The FAA estimates that it will take approximately 4 work hours per 
airplane to accomplish the required replacement of wheel halves at an 
average labor rate of $60 per work hour. Required parts will cost 
approximately $20,212 per airplane. Based on these figures, the cost 
impact of the required replacement on U.S. operators is estimated to be 
$4,928,932, or $20,452 per airplane.
    The FAA also estimates that it will take approximately 2 work hours 
per airplane to accomplish the required cleaning and inspection at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the required cleaning and inspection on U.S. operators 
is estimated to be $28,920, or $120 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.

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:

97-17-01 Boeing: Amendment 39-10102. Docket 96-NM-152-AD.

    Applicability: Model 737-100 and -200 series airplanes equipped 
with Bendix main wheel assemblies having part number 2601571-1, 
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 wheel flanges, which could result in 
damage to the hydraulics systems, jammed flight controls, loss of 
electrical power, or other combinations of failures and consequent 
reduced controllability of the airplane, accomplish the following:

    Note 2: Allied Signal, Aircraft Landing Systems, Service 
Information Letter #619, dated February 26, 1997, is an additional 
source of service information for appropriate wheel half serial 
numbers.

    (a) For airplanes equipped with a Bendix main wheel assembly 
having part number (P/N) 2601571-1 with an inboard wheel half with 
serial number (S/N) B-5898 or lower, or S/N H-1721 or lower; or with 
an outboard wheel half with S/N B-5898 or lower, or S/N H-0863 or 
lower; accomplish the following:
    (1) Within 180 days after the effective date of this AD, and 
thereafter at each tire change until the replacement required by 
paragraph (b) of this AD is accomplished: Accomplish the actions 
specified in paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii) of 
this AD, in accordance with the Accomplishment Instructions of 
Allied Signal Service Bulletin No. 737-32-026, dated April 26, 1988.
    (i) Clean any inboard and outboard wheel half specified in 
paragraph (a) of this AD. And
    (ii) Inspect the wheel halves for corrosion or missing paint. If 
any corrosion is found, or if any paint is missing in large areas, 
prior to further flight, strip or remove paint, and remove any 
corrosion. And

[[Page 43069]]

    (iii) Perform an eddy current inspection to detect cracks of the 
bead seat area.
    (2) If any cracking is found during the inspections required by 
this paragraph, prior to further flight, repair or replace the wheel 
halves with serviceable wheel halves in accordance with procedures 
specified in the Component Maintenance Manual.
    (b) For airplanes equipped with a Bendix main wheel assembly 
having P/N 2601571-1 with an inboard wheel half with S/N B-5898 or 
lower, or S/N H-1721 or lower; or with an outboard wheel half with 
S/N B-5898 or lower, or S/N H-0863 or lower; accomplish the 
following: Within 2 years after the effective date of this AD, 
accomplish the actions specified in paragraphs (b)(1) and (b)(2) of 
this AD, in accordance with Bendix Service Information Letter (SIL) 
392, Revision 1, dated November 15, 1979. Accomplishment of the 
replacement constitutes terminating action for the repetitive 
inspections required by paragraph (a) of this AD.
    (1) Remove any inboard wheel half specified in paragraph (b) of 
this AD, and replace it with an inboard wheel half having P/N 
2607046, S/N 5899 or greater, or S/N H-1722 or greater. And
    (2) Remove any outboard wheel half specified in paragraph (b) of 
this AD, and replace it with an outboard wheel half having P/N 
2607047, S/N B-5899 or greater, or S/N H-0864 or greater.
    (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, 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.
    (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) Certain actions shall be done in accordance with Bendix 
Service Information Letter (SIL) 392, Revision 1, dated November 15, 
1979. Certain other actions shall be done in accordance with Allied 
Signal Service Bulletin No. 737-32-026, dated April 26, 1988. 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 Allied Signal Aerospace Company, 
Aircraft Landing Systems, 3520 Westmoor Street, South Bend, Indiana 
46628-1373. 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 September 16, 1997.

    Issued in Renton, Washington, on August 4, 1997.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-20952 Filed 8-11-97; 8:45 am]
BILLING CODE 4910-13-U