[Federal Register Volume 59, Number 29 (Friday, February 11, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-2659]


[[Page Unknown]]

[Federal Register: February 11, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-108-AD; Amendment 39-8817; AD 94-03-10]

 

Airworthiness Directives; Lockheed Model L-1011 Series Airplanes 
Equipped With Rolls-Royce Model RB211-524 Series Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Lockheed Model L-1011 series airplanes, that 
requires modifying the engine high speed gearboxes. This amendment is 
prompted by a fire in the engine high speed gearbox due to failure of a 
roller bearing. The actions specified by this AD are intended to reduce 
the possibility of fire in the engine high speed gearbox, and to ensure 
that if a fire occurs, it is readily detected by the flight crew.

DATES: Effective March 14, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 14, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from Lockheed Western Export Company, Dept. 693, Zone 0755, 86 
South Cobb Drive, Marietta, Georgia 30063; or from Rolls-Royce PLC, 
Technical Publications Department, P.O. Box 17, Parkside, Coventry, 
England CV1 2LZ. 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 FAA, Small 
Airplane Directorate, Atlanta Aircraft Certification Office, suite 
210C, 1669 Phoenix Parkway, Atlanta, Georgia; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

FOR FURTHER INFORMATION CONTACT: Thomas Peters, Aerospace Engineer, 
Flight Test Branch, ACE-160A, FAA, Small Airplane Directorate, Atlanta 
Aircraft Certification Office, suite 210C, 1669 Phoenix Parkway, 
Atlanta, Georgia 30349; telephone (404) 991-3915; fax (404) 991-3606.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to Lockheed Model L-1011 series airplanes equipped with 
Rolls-Royce Model RB211-524 series engines was published in the Federal 
Register on September 29, 1993 (58 FR 50869). That action proposed to 
require modifying the engine high speed gearboxes by installing an 
additional fire detection system on the high speed gearboxes installed 
on the number 1, 2, and 3 engines; installing a new vent tube in the 
gear compartment of the high speed gearbox installed on the number 1, 
2, and 3 engines; and modification of the high speed gearbox breather 
duct installed on the number 2 engine.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposal.
    Another commenter has no objection to the proposed rule, but 
requests that the description of the addressed unsafe condition be 
revised. This commenter points out that the preamble to the notice 
indicated that the actions of the proposed rule are intended ``to 
prevent a fire in the engine high speed gearbox.'' However, the 
commenter contends that the actions will not prevent a fire from 
occurring; they will only detect a fire after it has burned through the 
gearbox. The FAA partially concurs with the commenter's request. While 
it is true that the installation of the fire detection sensor does 
nothing to prevent the initiation of a fire, the AD also requires the 
installation of a new vent tube in the gear compartment of the high 
speed gearbox in accordance with Rolls-Royce Service Bulletin RB.211-
72-4666, Revision 4, dated May 16, 1986. That service bulletin states, 
in part, that ``in repositioning the vent air exit, the oil/air mixture 
ratio is richened beyond the normal limits of combustion, therefore 
reducing the possibility of internal fires should a failed bearing 
overheat.'' In light of this, the FAA now considers that, although the 
required actions of the rule will not prevent a fire, they will 
contribute to reducing the possibility of fire in the engine high speed 
gearbox. The description of the unsafe condition has been revised in 
this final rule accordingly.
    This commenter also points out that the wording in the preamble to 
the notice indicated that failure of a roller bearing in the engine 
high speed gearbox could cause a fire internal to the gearbox, ``which 
could eventually breach the engine breather duct and potentially breach 
the gearbox.'' However, a more accurate description of this situation 
would be that ``failure of a roller bearing could cause a fire internal 
to the gearbox, which could (1) eventually breach the flexible engine 
breather duct within the engine cowls in the number 2 engine position, 
and (2) also breach the high speed gearbox casing at any engine 
position.'' The commenter states that the flexible engine breather duct 
is installed only on the number 2 engine; the wording in the preamble 
to the notice implies that each engine has both a gearbox and a 
flexible duct. The FAA agrees with the commenter's suggested rewording 
of this issue.
    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 as proposed.
    There are approximately 92 Model L-1011 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 24 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 18 work hours per airplane to accomplish the 
required actions, and that the average labor rate is $55 per work hour. 
If the airplane is equipped with the Walter Kidde fire detection 
system, required parts are estimated to cost $12,600 per airplane. If 
the airplane is equipped with the Graviner fire detection system, 
required parts are estimated to cost $18,600 per airplane. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be between $326,160 and $470,160, or between 
$13,590 and $19,590 per airplane.
    The total 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. However, the 
FAA has been advised that 19 airplanes of U.S. registry have been 
modified with the breather duct that is required by this rule; 
therefore, the future total cost impact of this AD on U.S. operators 
will be less than the figures indicated above.
    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:

94-03-10  Lockheed: Amendment 39-8817. Docket 93-NM-108-AD.

    Applicability: Model L-1011 series airplanes, equipped with 
Rolls-Royce Model RB211-524 series engines; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To reduce the possibility of a fire in the engine high speed 
gearbox, and to ensure that if a fire occurs, it is readily detected 
by the flight crew, accomplish the following:
    (a) Within the next 16,000 flight hours after the effective date 
of this AD, or within 48 months after the effective date of this AD, 
whichever occurs first, accomplish paragraphs (a)(1), (a)(2), and 
(a)(3) of this AD:
    (1) Install an additional fire detection system on the high 
speed gearbox on the number 1, number 2, and number 3 engines, in 
accordance with Lockheed Service Bulletin 093-26-039, dated November 
11, 1992.
    (2) Install a new vent tube in the gear compartment of the high 
speed gearbox on the number 1, number 2, and number 3 engines, in 
accordance with Rolls-Royce Service Bulletin RB.211-72-4666, 
Revision 4, dated May 16, 1986.

    Note 1: Installation of a new vent tube in accordance with 
Rolls-Royce Service Bulletin RB.211-72-4666, Revision 3, dated 
October 14, 1977, prior to the effective date of this AD, is 
considered acceptable for compliance with this AD.

    (3) Modify the breather duct of the high speed gearbox on the 
number 2 engine, in accordance with Lockheed Service Bulletin 093-
71-067, Revision 2, dated December 12, 1988.

    Note 2: Modification of the breather duct in accordance with 
Lockheed Service Bulletin 093-71-067, Revision 1, dated April 1, 
1986, prior to the effective date of this AD, is considered 
acceptable for compliance with this AD.

    (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, Atlanta Aircraft Certification 
Office (ACO), FAA, Small 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, Atlanta ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta 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 actions shall be done in accordance with Lockheed 
Service Bulletin 093-26-039, dated November 11, 1992; Lockheed 
Service Bulletin 093-71-067, Revision 2, dated December 12, 1988; 
and Rolls-Royce Service Bulletin RB.211-72-4666, Revision 4, dated 
May 16, 1986, which contains the following list of effective pages:-

                                                                        
------------------------------------------------------------------------
                                    Revision                            
            Page No.              level shown      Date shown on page   
                                    on page                             
------------------------------------------------------------------------
1-4.............................            4  May 16, 1986.            
4A, 5-6, 6A, 7-10...............            2  August 26, 1977.         
Supplement:                                                             
1...............................            3  October 14, 1977.        
2...............................            2  August 26, 1977.         
------------------------------------------------------------------------

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 Lockheed Western Export Company, 
Dept. 693, Zone 0755, 86 South Cobb Drive, Marietta, Georgia 30063; 
or from Rolls-Royce PLC, Technical Publications Department, P.O. Box 
17, Parkside, Coventry, England CV1 2LZ. Copies may be inspected at 
the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington; or at the FAA, Small Airplane Directorate, 
Atlanta Aircraft Certification Office, suite 210C, 1669 Phoenix 
Parkway, Atlanta, Georgia; or at the Office of the Federal Register, 
800 North Capitol Street, NW., suite 700, Washington, DC.
    (e) This amendment becomes effective on March 14, 1994.

    Issued in Renton, Washington, on February 1, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-2659 Filed 2-10-94; 8:45 am]
BILLING CODE 4910-13-U