[Federal Register Volume 69, Number 107 (Thursday, June 3, 2004)]
[Proposed Rules]
[Pages 31325-31327]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-12576]


 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 69, No. 107 / Thursday, June 3, 2004 / 
Proposed Rules  

[[Page 31325]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-06-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707 and 720 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to all Boeing Model 707 and 
720 series airplanes, that currently requires inspections of the upper 
and lower chords of the wing front and rear spars, repair if necessary, 
and application of corrosion inhibitor to the inspected areas. This 
action would remove the requirements of the existing AD, require new 
detailed inspections and new high frequency eddy current (HFEC) 
inspections for corrosion and cracking, and require certain related 
follow-on and investigative actions, if necessary. This action also 
would expand the area of inspection to include the dry bay areas. The 
actions specified by the proposed AD are intended to find and fix 
corrosion and stress corrosion cracking of the upper and lower chords 
on the wing front and rear spars, which could result in reduced 
structural integrity of the wing. This action is intended to address 
the identified unsafe condition.

DATES: Comments must be received by July 19, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-06-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-06-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 Airplanes, 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: Candice Gerretsen, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6428; 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:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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-06-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-06-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On April 11, 2001, the FAA issued AD 2001-08-02, amendment 39-12179 
(66 FR 20383, April 23, 2001), applicable to all Boeing Model 707 and 
720 series airplanes, to require inspections of the upper and lower 
chords of the wing front and rear spars, repair if necessary, and 
application of corrosion inhibitor to the inspected areas. That action 
was prompted by a report indicating that a 31-inch crack was found in 
the radius of the lower chord of the wing front spar in the dry bay 
area between wing stations 360 and 400. Investigation revealed that 19 
inches of the crack were due to stress corrosion, while the remainder 
was due to ductile separation. The requirements of that AD are intended 
to find and fix stress corrosion cracking of the upper and lower chords 
on the wing front and rear spars, which could result in reduced 
structural integrity of the wing.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA has received a report 
indicating that an operator had found a 31-inch crack during a routine 
inspection six months after it had done the inspection described in 
Boeing Service Bulletin 3240, Revision 3, dated October 18, 1985 (a 
referenced source of service information in AD 2001-08-02).

[[Page 31326]]

Explanation of Relevant Service Information

    We have reviewed and approved Boeing 707 Alert Service Bulletin 
A3240, Revision 4, dated September 6, 2001. Revision 4 puts more 
emphasis than Revision 3 on the detailed inspections for corrosion of 
the upper and lower chords on the front and rear spars, adds a new high 
frequency eddy current (HFEC) inspection for corrosion and cracking, 
and expands the area of inspection to include the dry bay areas of the 
wings. Revision 4 also describes procedures for repair of corrosion and 
follow-on actions (removing finish, applying a chemical film treatment 
and primer to certain areas, measuring depth of any removed material, 
and accomplishing further HFEC inspections, if necessary) for 
conditions within certain areas or limits. For certain conditions 
outside the areas or limits specified by Revision 4, the service 
bulletin specifies that operators contact Boeing for repair. Revision 4 
also specifies that operators contact Boeing for any cracking that is 
found. Accomplishment of the actions specified in the service bulletin 
is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Pertinent requirements of existing ADs are generally restated in a 
proposed AD. However, due to the complexity of the requirements of AD 
2001-08-02 and the fact that some of the requirements of that AD are no 
longer correct or necessary, we have clarified in Note 1 of this 
proposed AD that the requirements specified in this proposed AD remove 
the requirements specified in AD 2001-08-02. We have determined that 
the actions and compliance times specified in this proposed AD would 
adequately address the identified unsafe condition in a timely manner.
    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 actions specified in 
Revision 4 of Boeing 707 Alert Service Bulletin A3240, dated September 
6, 2001. Except as described below, the actions would be required to be 
accomplished in accordance with Revision 4.

Difference Between the Service Bulletin and the Proposed AD

    Although the service bulletin specifies that operators should 
contact the manufacturer for certain conditions outside the limits 
specified in the service bulletin and for disposition of any cracking 
found, this proposed AD would require operators to repair such 
conditions or cracking per a method approved by the FAA.
    Additionally, where the service bulletin recommends doing the 
detailed inspections described in Boeing All Base Message M-7200-01-
00062 within 30 days after the release of the service bulletin, this 
proposed AD would require accomplishment of the detailed inspections of 
the areas per Revision 4 of Boeing 707 Alert Service Bulletin A3240, 
dated September 6, 2001, within 30 days after the effective date of the 
AD.
    Where the service bulletin specifies applying BMS 3-23 corrosion 
inhibitor or a Boeing approved equivalent, this proposed AD would 
require that any application of an equivalent corrosion inhibitor be 
approved by the FAA.

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 230 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 42 airplanes of U.S. registry 
would be affected by this proposed AD.
    The new actions that are proposed in this AD would not include 
those actions required by AD 2001-08-02. Therefore, cost impact figures 
for those actions are not necessary nor provided for in this proposed 
AD.
    The new actions that are proposed in this AD action would take 
approximately 212 work hours per airplane to accomplish, at an average 
labor rate of $65 per work hour. Based on these figures, the cost 
impact of the proposed requirements of this AD on U.S. operators is 
estimated to be $578,760, or $13,780 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the current or proposed 
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 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 removing amendment 39-12179 (66 FR 
20383, April 23, 2001), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2003-NM-06-AD. Supersedes AD 2001-08-02, Amendment 
39-12179.

    Applicability: All Model 707 and 720 series airplanes, 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To find and fix corrosion and stress corrosion cracking of the 
upper and lower

[[Page 31327]]

spar chords on the front and rear spars of the wing, which could 
result in reduced structural integrity of the wing, accomplish the 
following:

Superseding the Requirements of AD 2001-08-02

    Note 1: As of the effective date of this AD, the requirements of 
AD 2001-08-02, amendment 39-12179, are no longer effective or 
required.

Definition of Service Bulletin

    (a) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing 707 Alert Service Bulletin 
A3240, Revision 4, dated September 6, 2001.

Detailed Inspection

    (b) Within 30 days after the effective date of this AD, do a 
detailed inspection of the entire length of the external surfaces of 
the front and rear wing spar chords and the internal surfaces of the 
front spar chords in the dry bays of the wings for corrosion, any 
signs of corrosion (e.g., blistering or signs of fuel leaks), or 
cracking; per the Accomplishment Instructions of the service 
bulletin. If no corrosion or cracking is found, before further 
flight: Except as specified in paragraph (e) of this AD, accomplish 
any applicable follow-on actions or investigative actions, per the 
Accomplishment Instructions of the service bulletin.

Other Repetitive Inspections

    (c) Within 6 months after the effective date of this AD, perform 
a detailed inspection and a high frequency eddy current (HFEC) 
inspection of the entire length of the external surfaces of the 
front and rear wing spar chords and the internal surfaces of the 
front spar chords in the dry bays of the wings for any corrosion, 
signs of corrosion (e.g., blistering or signs of fuel leaks), or 
cracking; per the Accomplishment Instructions of the service 
bulletin. If no corrosion or cracking is found, before further 
flight, accomplish any applicable follow-on or investigative actions 
specified in the Accomplishment Instructions of the service bulletin 
and the actions specified in paragraph (e) of this AD. Thereafter, 
repeat the detailed and HFEC inspections at intervals not to exceed 
12 months.

Repair of Corrosion

    (d) If any corrosion or signs of corrosion (e.g., blistering or 
signs of fuel leaks) are found during any inspection required by 
this AD: Before further flight, repair per paragraph (d)(1) or 
(d)(2) of this AD, as applicable.
    (1) If the corrosion is within the areas and limits specified in 
the service bulletin: Except as required by paragraph (e) of this 
AD, repair and accomplish all applicable follow-on and investigative 
actions, per the Accomplishment Instructions of the alert service 
bulletin.
    (2) If the corrosion is outside the areas or limits specified in 
the service bulletin, repair per a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO), FAA; or per data 
meeting the type certification basis of the airplane approved by a 
Boeing Company Designated Engineering Representative (DER) who has 
been authorized by the Manager, Seattle ACO, to make such findings. 
For a repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the approval letter must specifically 
reference this AD.

Application of Corrosion Inhibitor

    (e) Where the Accomplishment Instructions of the service 
bulletin specifies to apply BMS 3-23 (a corrosion inhibitor) or a 
Boeing approved equivalent, this AD requires that BMS 3-23 must be 
used or that any application of an equivalent corrosion inhibitor be 
approved by the Manager, Seattle ACO, or per data meeting the type 
certification basis of the airplane approved by a Boeing Company DER 
who has been authorized by the Manager, Seattle ACO, to make such 
findings. For a repair method to be approved by the Manager, Seattle 
ACO, as required by this paragraph, the approval letter must 
specifically reference this AD.

Repair of Cracking

    (f) If any cracking is found during any inspection required by 
this AD, including cracks that have been previously stop-drilled but 
not permanently repaired: Before further flight, repair per a method 
approved by the Manager, Seattle ACO; or per data meeting the type 
certification basis of the airplane approved by a Boeing Company DER 
who has been authorized by the Manager, Seattle ACO, to make such 
findings. For a repair method to be approved by the Manager, Seattle 
ACO, as required by this paragraph, the approval letter must 
specifically reference this AD. Operators should note that ``stop 
drilling'' of cracks as a means to defer repair is not permitted by 
this AD.

Alternative Methods of Compliance

    (g) 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 May 26, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-12576 Filed 6-2-04; 8:45 am]
BILLING CODE 4910-13-P