[Federal Register Volume 60, Number 239 (Wednesday, December 13, 1995)]
[Proposed Rules]
[Pages 63989-63991]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-30353]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-124-AD]


Airworthiness Directives; Boeing Model 767 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 certain Boeing Model 767 
series airplanes, that currently requires an inspection of the control 
rods of the outboard leading edge slat, and follow-on actions 
(including repetitive ultrasonic inspections), if necessary. That AD 
also requires replacement of the control rod ends and attach bolts for 
certain airplanes. It also provides for an optional terminating action 
for follow-on repetitive inspections. That AD was prompted by reports 
of cracks and worn attach bolts of the control rods of the leading edge 
outboards slats of the wings due to the high breakout torque in the 
joint of the control rod end. This action would require installation of 
the previously optional terminating action. The actions specified by 
the proposed AD are intended to prevent reduced controllability of the 
airplane and damage in the slat structure or fixed leading edge of the 
wing, as a result of cracks and worn attach bolts.

DATES: Comments must be received by January 24, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-124-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays. 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: Kristin Larson, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington; 
telephone (206) 227-1760; fax (206) 227-1181.

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 notice may be changed in 
light of the comments received.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-124-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-103, Attention: Rules 
Docket No. 95-NM-124-AD, 1601 Lind Avenue SW., Renton, Washington 
98055-4056.

Discussion

    On September 5, 1990, the FAA issued AD 90-20-16, amendment 39-6726 
(55 FR 37858, September 14, 1990), applicable to certain Boeing Model 
767 series airplanes, to require a one-time visual inspection to 
determine the date of manufacture of the control rods of the outboard 
leading edge slat, and follow-on actions, if necessary. Certain of the 
follow-on actions entail performing repetitive ultrasonic inspections 
of the control rods. That AD also requires replacement of the control 
rod ends and attach bolts, for certain airplanes. It also provided for 
an optional terminating action for the follow-on repetitive 
inspections. That action was prompted by a report that certain 
airplanes could be operating with control rods of the outboard leading 
edge slat that are subject to cracking. The requirements of that AD are 
intended to prevent the loss of the pilot's ability to control the 
affected slat, which could adversely affect the controllability of the 
airplane.
    Since the issuance of that AD, the FAA has reviewed and approved 
Revision 5 of Boeing Service Bulletin 767-57-0021, dated June 15, 1995. 
The one-time visual inspection and the replacement of the control rod 
ends and attach bolts procedures described in this revision are 
essentially identical to those described in Revision 1 and Revision 2 
of the service bulletin (which were referenced in AD 90-20-16). For 
certain airplanes, Revision 5 of the service bulletin describes 
procedures for replacement of the control rod with a control rod that 
has been manufactured after June 1983. The control rod ends of these 
newer control rods have improved bearings and chrome plated bolts, and 
a lower break-out torque, all of which will reduce wear of the attach 
bolts of the control rods. Accomplishment of this replacement 
eliminates the need for the (follow-on) repetitive ultrasonic 
inspections described in Revision 1 and Revision 2 of the service 
bulletin.
    The FAA has determined that accomplishment of the replacement of 
the control rod with a new control rod that has been manufactured after 
June 1983, will positively address the unsafe condition identified as 
loss of the pilot's ability to control the affected slat, which could 
adversely affect the controllability of the airplane.
    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 supersede AD 90-20-16. It would continue to require a 
one-time visual inspection to determine the date of manufacture of the 
control rods of the outboard leading edge slat, and follow-on actions 
(i.e., repetitive ultrasonic inspection), if necessary. The proposed AD 
would also continue to require replacement of the control rod ends and 
attach bolts, for certain airplanes. For operators accomplishing the 
(follow-on) repetitive ultrasonic inspections, the proposed AD would 
require replacement of the control rod with a new control rod 
manufactured after June 1983; this replacement would constitute 
terminating action for the repetitive inspections. The actions would be 
required to be accomplished in accordance with the service bulletins 
described previously.
    There are approximately 271 Model 767 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 193 
airplanes of U.S. 

[[Page 63991]]
registry would be affected by this proposed AD.
    The actions that are currently required by AD 90-20-16 take 
approximately 21 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts cost approximately 
$5,500 per airplane. Based on these figures, the cost impact on U.S. 
operators of the actions currently required is estimated to be 
$1,304,680, or $6,760 per airplane.
    For certain affected airplanes, the new replacement (terminating) 
action that is proposed in this AD would take approximately 1 work hour 
per airplane to accomplish, at an average labor rate of $60 per work 
hour. The cost of required replacement parts is estimated to be $5,500 
per airplane. Based on these figures, the cost impact on U.S. operators 
of the proposed requirements of this AD is estimated to be $5,560 per 
airplane.
    The cost impact figures discussed above are 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 regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-6726 (55 FR 
37858, September 14, 1990), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 95-NM-124-AD. Supersedes AD 90-20-16, Amendment 39-
6726.

    Applicability: Model 767 series airplanes, as listed in Boeing 
Service Bulletin 767-57-0021, Revision 1, dated September 14, 1989, 
or Revision 5, dated June 15, 1995; 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 use the authority 
provided in paragraph (c) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously. To prevent loss of the pilot's ability to control the 
affected slat, which could adversely affect the controllability of 
the airplane, accomplish the following:
    (a) For airplanes having line positions 1 through 235 inclusive: 
Within the next 1,200 landings or 9 months after October 23, 1990 
(the effective date of AD 90-20-16, amendment 39-6726), whichever 
occurs first, unless accomplished within the last 800 landings or 6 
months, whichever occurs later, perform a visual inspection to 
determine the date of manufacture of the control rods of the 
outboard leading edge slat of the wings, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 767-57-0021, 
dated August 25, 1988; Revision 1, dated September 14, 1989; 
Revision 2, dated July 26, 1990; or Revision 5, dated June 15, 1995.
    (1) If the date of manufacture (stamped on the control rod) is 
June 1983 or later, no further action is required by this paragraph.
    (2) If the date of manufacture is illegible or is prior to June 
1983, accomplish paragraphs (a)(2)(i) and (a)(2)(ii) of this AD.
    (i) Prior to further flight, perform an ultrasonic inspection to 
detect cracks of the control rods in accordance with Figure 1 of 
Boeing Service Bulletin 767-57-0021, dated August 25, 1988, Revision 
1, dated September 14, 1989, or Revision 2, dated July 26, 1990. If 
any crack or fracture is detected, prior to further flight, replace 
it in accordance with Figure 2 of the service bulletin. Repeat the 
ultrasonic inspection of the control rods manufactured prior to June 
1983 thereafter at intervals not to exceed 2,000 landings or 15 
months, whichever occurs first, until the replacement required by 
paragraph (a)(2)(ii) of this AD is accomplished.
    (ii) Within 3,000 flight hours or 15 months after the effective 
date of this AD, whichever occurs later, replace the control rod 
with a new rod manufactured June 1983 or later, in accordance with 
Boeing Service Bulletin 767-57-0021, Revision 5, dated June 15, 
1995. Accomplishment of this replacement constitutes terminating 
action for the repetitive inspection requirement of paragraph 
(a)(2)(i) of this AD.
    (b) For airplanes having line number 1 through 264 inclusive, 
and 266 through 273 inclusive: Within the next 2,500 landings or 18 
months after October 23, 1990 (the effective date of AD 90-20-16, 
amendment 39-6726, whichever occurs first, replace the control rod 
end and attach bolt with a new configuration control rod end and 
attach bolt on each wing, in accordance with Boeing Service Bulletin 
767-57-0221, Revision 1, dated September 14, 1989; Revision 2, dated 
July 26, 1990; or Revision 5, dated June 15, 1995.
    (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 2: 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.

    Issued in Renton, Washington, on December 7, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-30353 Filed 12-12-95; 8:45 am]
BILLING CODE 4910-13-U