[Federal Register Volume 59, Number 9 (Thursday, January 13, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-24]


[[Page Unknown]]

[Federal Register: January 13, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-127-AD; Amendment 39-8784; AD 94-01-02]

 

Airworthiness Directives; Boeing Model 767 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 certain Boeing Model 767 series airplanes, that requires 
modification of the ram air turbine (RAT) system wiring. This amendment 
is prompted by a report of chatter occurring during takeoff and landing 
in the RAT airspeed switch relay. The actions specified by this AD are 
intended to prevent the inability to maintain hydraulic system power in 
the event that power is lost in both engines.

DATES: Effective February 14, 1994.

    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 14, 1994.
ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. 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: Kristin Larson, 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 (206) 227-1760; fax (206) 
227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to certain Boeing Model 767 series airplanes was published 
in the Federal Register on September 17, 1993 (58 FR 48617). That 
action proposed to require modification of the ram air turbine (RAT) 
system wiring.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Three commenters support the proposed rule.
    The Air Transport Association (ATA) of America, on behalf of one of 
its members, requests that the proposed compliance time be extended to 
allow the proposed modification to be accomplished within 4,000 hours 
time-in-service or 15 months after the effective date of the rule, 
whichever occurs later. This will allow the proposed modification to be 
accomplished during the time of a regularly scheduled ``C'' check. The 
commenter considers that the adoption of the proposed compliance time 
of 4,000 hours time-in-service would require scheduling special times 
for the accomplishment of the modification, at additional expense.
    The FAA concurs with the commenter's request to extend the 
compliance time. Extending the compliance time as suggested by the 
commenter will not adversely affect safety, and will allow the 
modification to be performed at a base during regularly scheduled 
maintenance where special equipment and trained maintenance personnel 
will be available if necessary. Paragraph (a) of the final rule has 
been revised accordingly.
    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 change previously 
described. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 90 Model 767 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 53 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 3.5 work hours per airplane to accomplish the 
required actions, and that the average labor rate is $55 per work hour. 
The cost for required parts will be minimal. Based on these figures, 
the total cost impact of the AD on U.S. operators is estimated to be 
$10,203, or $193 per airplane. This total cost figure assumes that no 
operator has yet accomplished the requirements of this AD.
    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 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-01-02 Boeing: Amendment 39-8784. Docket 93-NM-127-AD.

    Applicability: Model 767 series airplanes; as listed in Boeing 
Service Bulletin 767-29-0021, Revision 4, dated May 12, 1988; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously. To prevent the inability to maintain hydraulic system 
power in the event that power is lost in both engines, accomplish 
the following:
    (a) Within 4,000 hours time-in-service or 15 months after the 
effective date of this AD, whichever occurs later, replace the ram 
air turbine (RAT) airspeed switch; cap and stow the wire between the 
RAT airspeed switch and the air/ground relay; and perform a 
functional test of the RAT deployment system; in accordance with 
Boeing Service Bulletin 767-29-0021, Revision 4, dated May 12, 1988.
    (b) 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: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (c) Special flight permits may be issued in accordance with FAR 
21.197 and 21.199 to operate the airplane to a location where the 
requirements of this AD can be accomplished.
    (d) The modification shall be done in accordance with Boeing 
Service Bulletin 767-29-0021, Revision 4, dated May 12, 1988, which 
contains the following list of effective pages:

                                                                        
------------------------------------------------------------------------
                       Revision                                         
                        level                                           
     Page number       shown on             Date shown on page          
                         page                                           
------------------------------------------------------------------------
1-4, 6, 10..........          4  May 12, 1988                           
5, 7-9, 11-14.......          1  August 10, 1984.                       
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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 Boeing Commercial Airplane 
Group, P.O. Box 3707, Seattle, Washington 98124-2207. 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.
    (e) This amendment becomes effective on February 14, 1994.

    Issued in Renton, Washington, on December 28, 1993.
Bill R. Boxwell,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-24 Filed 1-12-94; 8:45 am]
BILLING CODE 4910-13-P