[Federal Register Volume 59, Number 245 (Thursday, December 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-31179]


[[Page Unknown]]

[Federal Register: December 22, 1994]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-227-AD; Amendment 39-9101; AD 94-26-05]

 

Airworthiness Directives; Airbus Industrie Model A300, A300-600, 
A310, and A320 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Airbus Industrie Model A300, A300-600, A310, and 
A320 series airplanes, that requires inspection of certain landing gear 
brakes for wear and replacement if the wear limits prescribed in this 
AD are not met, and incorporation of the specified wear limits into the 
FAA-approved maintenance inspection program. This amendment is prompted 
by an accident in which a transport category airplane executed a 
rejected takeoff (RTO) and was unable to stop on the runway due to worn 
brakes; and the subsequent review of allowable brake wear limits for 
all transport category airplanes. The actions specified by this AD are 
intended to prevent the loss of brake effectiveness during a high 
energy RTO.

EFFECTIVE DATE: January 23, 1995.

ADDRESSES: Information pertaining to this rulemaking action 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: Mark Quam, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2145; fax (206) 227-1320.

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 certain Airbus Industrie Model 
A300, A300-600, A310, and A320 series airplanes was published in the 
Federal Register on February 15, 1994 (59 FR 7228). That action 
proposed to require inspection of certain landing gear brakes for wear 
and replacement if the wear limits prescribed in this AD are not met, 
and incorporation of the specified wear limits into the FAA-approved 
maintenance inspection program.
    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 proposed rule.
    One commenter, BFGoodrich, requests that the tables contained in 
the proposal that list maximum brake wear limits for the affected 
airplanes be revised. BFGoodrich indicates that the airplane model/
series listed for BFGoodrich series 2-1526 brake part numbers should be 
``A320,'' instead of ``A320-220'' and ``A320-200.'' The commenter also 
indicates that three additional part numbers for BFGoodrich brakes 
should be listed in the tables for Model A320 series airplanes: Part 
numbers 2-1526, 2-1526-5 (both with maximum wear limits of 1.97''), and 
2-1572 (with a maximum wear limit of 2.68'').
    While the FAA agrees with the commenter's remarks, inclusion of the 
three additional part numbers specified by the commenter would 
necessitate (under the provisions of the Administrative Procedure Act) 
reissuing the notice, reopening the period for public comment, 
considering additional comments received, and eventually issuing a 
final rule; the time required for that procedure may be as long as four 
additional months. In the interest of issuing this final rule, and in 
consideration of the amount of time that has already elapsed since 
issuance of the original notice, the FAA has determined that further 
delay of this final rule action is not appropriate. However, the FAA 
may consider further rulemaking on this issue to address the three 
additional part numbers discussed by the commenter.
    The Air Transport Association (ATA) of America, on behalf of one of 
its members, suggests that measuring the maximum length of the wear pin 
may not be as effective as measuring the total length of the wear pin 
or controlling the carbon thickness of the brake. The commenter points 
out that, due to human error, it is possible to have a thinner disc 
with the same amount of wear pin length showing.
    The FAA does not concur. The FAA infers from the commenter's 
remarks that it is referring to controlling the carbon thickness of the 
brakes by direct measurement of the thickness of the brake stack. The 
FAA finds that measuring the thickness of the brake stack would only be 
useful when specifying the brake assembly configuration and the 
thicknesses of new, refurbished, or overhauled individual discs. 
Otherwise, a brake disc that is too thin also could be installed in a 
brake stack having a wear limit that is controlled by measuring the 
stack thickness. Further, it would not be practical to routinely 
measure the brake stack on the airplane as all of the wheels attached 
to the brakes would have to be removed to allow access to accomplish 
the measurement. The FAA considers that this would pose an unwarranted 
burden on operators. Currently, only the wear pin must be monitored 
while the brake is installed on the airplane. If an operator reduces 
the wear limit, the pin could be shortened or the operator could devise 
a method of accounting for the reduced wear using the existing wear pin 
as opposed to removing the wheel and measuring the brake stack. (Thus, 
the wheels would not have to be removed from the airplane since the 
wear pin can still be used to monitor brake wear.)
    The wear limits specified in this AD, which are used to establish 
wear pin lengths, are interdependent with the brake configuration and 
minimum disc and stack thicknesses. The stack and disc thicknesses are 
specified for new, refurbished, or overhauled brakes in the airplane 
maintenance manual (AMM), the component maintenance manual (CMM), a 
service bulletin, or the brake manufacturer's assembly drawings. These 
minimum brake stack and disc thicknesses have been established by tests 
and in-service wear data and analysis such that monitoring a wear pin 
should not allow the stack or disc minimum limits to be exceeded.
    The ATA also questions the need for the proposed AD, and requests 
that a provision be included in paragraph (a)(2) of the AD to state 
that the AD would no longer be applicable to operators that have 
acceptably revised their maintenance programs, and that operators 
choosing this provision could use an alternative recordkeeping method 
in lieu of that required by Secs. 91.417 or 121.380 of the Federal 
Aviation Regulations (14 CFR 91.417 or 121.380). The FAA would be 
defined as the cognizant Principal Maintenance Inspector (PMI) for 
operators electing this alternative.
    The ATA states that if its suggested provision is not included, 
confusion will always exist as to what records should be maintained for 
the duration A300/A320 operations. The ATA maintains that once an 
operator incorporates the criteria (brake wear limits) specified in the 
proposal into the maintenance program, the AD should be signed off as 
complete, since such incorporation is the stated purpose of the AD. The 
ATA is aware of an FAA concern that the proposed type of rule must 
continue indefinitely because operators may otherwise escalate 
intervals through their reliability programs. The ATA states that 
adjustments to operators' programs are accomplished with substantiation 
and with the approval of FAA Flight Standards District Offices (FSDO). 
The ATA maintains that FAA FSDO's have sufficient authority to ensure 
that operators maintain the brakes on their Model A300/A320 series 
airplanes once the proposed criteria (brake wear limits) have been 
incorporated into an operator's maintenance program.
    The FAA does not concur. The intent of this AD is that operators 
incorporate maximum brake wear limits into the FAA-approved maintenance 
inspection program, and that all brakes be inspected once for wear and 
replaced, if necessary. Once an operator has complied with the 
requirements of this AD, the FAA does not intend that operators 
subsequently record the accomplishment of this AD each time a brake is 
inspected or overhauled in accordance with that operator's FAA-approved 
maintenance inspection program. ``NOTE 2'' has been added to paragraph 
(a) of the final rule to clarify this intent. Operators should 
coordinate recordkeeping for accomplishment of the actions required by 
this AD with the cognizant Principal Maintenance Inspector (PMI).
    One ATA member requests that carbon brakes be excluded from the 
applicability of the proposed rule. Airbus adds its concurrence with 
the ATA member's request, and has advised the ATA that all carbon 
brakes installed on airplanes manufactured by Airbus are capable of 
sustaining a maximum energy rejected takeoff (RTO) in a 100 percent 
worn brake configuration. Airbus also states that no unsafe condition 
has been identified for airplanes having carbon brakes.
    Airbus also indicates that issuance of an AD to require 
implementation of existing CMM limits would impose unnecessary 
inspections (with associated costs) and would create an unnecessary 
paperwork burden on operators. Airbus states that, if the proposed rule 
is adopted, then an inspection would be required for all airplanes, not 
just the 28 airplanes specified in the economic impact information of 
the proposal.
    The FAA does not concur. As discussed in the preamble of the 
proposal, this AD, as well as other previously issued AD's to mandate 
specific maximum brake wear limits on transport category airplanes, was 
prompted by an accident in 1988 involving worn brakes on a McDonnell 
Douglas Model DC-10 series airplane. During the process of promulgating 
those AD's, the FAA became aware that not all operators were following 
the manufacturer's recommended brake wear limits. The FAA acknowledges 
that the wear limits for carbon brakes have not changed. However, the 
purpose of this AD is simply to establish the correct brake wear limits 
for the affected airplanes, including those on which carbon brakes 
having unchanged brake wear limits, are installed.
    The FAA acknowledges that operators of airplanes having carbon 
brakes will be required to confirm that inspections are being 
accomplished and to record compliance with this AD. However, if an 
operator already operates in accordance with the wear limits specified 
in this AD, as implied by ATA and Airbus, then only the costs 
associated with confirming compliance with the AD and recording such 
compliance are necessary. The economic impact information specified 
below addresses 46 airplanes that will be required to accomplish the 
inspection specified in this AD. (This number, 46, has been revised 
from the 28 airplanes specified in the proposal; the FAA's latest 
information is that 46 airplanes will be affected by the inspection 
requirement.) However, carbon brakes may be installed on some of those 
airplanes; therefore, some of the 46 airplanes addressed in this AD 
already may be operated in accordance with its provisions. Therefore, 
the actual total cost impact of this AD on U.S. operators may be less 
than the cost reflected in the cost estimate information, below.
    One commenter requests that the brake wear limit specified in the 
proposed rule for brake part numbers 2-1526-3 and 2-1526-4 should be 
revised to read 2.68'' (68 mm), rather than 1.97'' (50 mm). The 
commenter indicates that the maximum brake wear limit of 1.97'' (50 mm) 
is already standard for brake part numbers 2-1526-1 and 2-1526-2, 
whereas a wear limit of 2.68'' (68 mm) is specified in the CMM for 
brake part numbers 2-1526-3 and 2-1526-4 due to a different 
configuration that allows greater wear pin length and still maintains 
RTO performance at the maximum wear limit.
    The FAA finds that no change to the final rule is necessary in this 
regard. The proposed rule, as published in the Federal Register on 
February 15, 1994, specified the correct brake wear limit of 2.68'' (68 
mm) for brake part numbers 2-1526-3 and 2-1526-4. That same brake wear 
limit is contained in this final rule.
    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.
    The FAA has recently reviewed the figures it has used over the past 
several years in calculating the economic impact of AD activity. In 
order to account for various inflationary costs in the airline 
industry, the FAA has determined that it is necessary to increase the 
labor rate used in these calculations from $55 per work hour to $60 per 
work hour. The economic impact information, below, has been revised to 
reflect this increase in the specified hourly labor rate. In addition 
to the number of affected airplanes of U.S. registry that will be 
required to accomplish the inspection (as discussed previously), the 
FAA has updated the total number of airplanes of U.S. registry and the 
number of affected U.S. operators to reflect the latest information 
available.
    The FAA estimates that 165 Model A300, A300-600, A310, and A320 
series airplanes of U.S. registry and 7 U.S. operators will be affected 
by this AD, that it will take approximately 20 work hours per operator, 
at an average labor rate of $60 per work hour, for each operator to 
incorporate the revision of its FAA-approved maintenance inspection 
program. Based on these figures, the total cost impact of that 
requirement on U.S. operators is estimated to be $8,400, or $1,200 per 
operator.
    The FAA also estimates that it will take 15 work hours per 
airplane, at an average labor rate of $60 per work hour, to accomplish 
the required inspection. The cost of required parts to accomplish the 
change in wear limits for these airplanes (that is, the cost resulting 
from the requirement to change the brakes before they are worn to their 
previously approved limits for a one-time change) will be approximately 
$2,236 per airplane. The FAA estimates that 46 of the 165 affected 
airplanes of U.S. registry will be required to accomplish the 
inspection. Based on these figures, the total cost impact of that 
requirement on U.S. operators of these airplanes is estimated to be 
$144,256, or $3,136 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no affected operator has accomplished all of the 
requirements of this AD action, and that no affected operator would 
accomplish all of those actions in the future if this AD were not 
adopted.
    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, 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. 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:

94-26-05  Airbus Industrie: Amendment 39-9101. Docket 93-NM-227-AD.

    Applicability: Model A300, A300-600, A310, and A320 series 
airplanes equipped with Messier-Bugatti, BFGoodrich, Allied Signal 
(ALS) Aerospace Company (Bendix), or Aircraft Braking Systems (ABS) 
brakes; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the loss of brake effectiveness during a high energy 
rejected takeoff (RTO), accomplish the following:
    (a) Within 180 days after the effective date of this AD, 
accomplish paragraphs (a)(1) and (a)(2) of this AD.
    (1) Inspect main landing gear brakes having the brake part 
numbers listed below for wear. Any brake worn more than the maximum 
wear limit specified below must be replaced, prior to further 
flight, with a brake within that limit.

      Airbus Industrie Model A300, A300-600, A310, and A320 Series Airplanes Equipped With Messier-Bugatti,     
      BFGoodrich, Allied Signal (ALS) Aerospace Company (Bendix), or Aircraft Braking Systems (ABS) Brakes      
----------------------------------------------------------------------------------------------------------------
                                                                                 Maximum brake wear limit (inch/
 Airplane model/series      Brake manufacturer           Brake part No.                        mm)              
----------------------------------------------------------------------------------------------------------------
A300-B2-100-...........  Messier-Bugatti........  286349-115                    0.98'' (25.0 mm)                
A300-B2-100-...........  Messier-Bugatti........  286349-116                    0.98'' (25.0 mm)                
A300-B2-100-...........  BFGoodrich.............  2-1449                        1.4'' (35.6 mm)                 
A300-B2-100-...........  BFGoodrich.............  2-1449                        1.1'' (27.9 mm) S.C.*           
A300-B4-100-...........  Messier-Bugatti........  A21329-41-7-                  1.1'' (28.0 mm)                 
A300-B4-100-...........  Messier-Bugatti........  A21329-41-17                  1.1'' (28.0 mm)                 
A300-B4-100-...........  ALS (Bendix)...........  2606802-3/-4/-5               0.9'' (22.9 mm)                 
A300-B4-100-...........  ALS (Bendix)...........  2606802-3/-4/-5               1.48'' (37.6 mm) S.C.*          
A300-B4-100-...........  BFGoodrich.............  2-1449                        1.4'' (35.6 mm)                 
A300-B4-100-...........  BFGoodrich.............  2-1449                        1.1'' (27.9 mm) S.C.*           
A300-B4-200 & A300-600.  Messier-Bugatti........  C20060-100                    1.1'' (28.0 mm)                 
A300-B4-200 & A300-600.  ALS (Bendix)...........  2607932-1                     0.9'' (22.9 mm)                 
A300-B4-200 & A300-600.  ALS (Bendix)...........  2607932-1                     1.48'' (37.6 mm) S.C.*          
A300-B4-600R...........  Messier-Bugatti........  C20210000                     1.97'' (50.0 mm)                
A300-B4-600R...........  Messier-Bugatti........  C20210200                     1.97'' (50.0 mm)                
A310-200...............  Messier-Bugatti........  C20089000                     1.1'' (28.0 mm)                 
A310-200...............  ALS (Bendix)...........  2606822-1                     1.26'' (32.0 mm)                
A310-200...............  ALS (Bendix)...........  2606822-1                     1.5'' (38.2 mm) S.C.*           
A310-300...............  Messier-Bugatti........  C20194000                     1.97'' (50.0 mm)                
A310-300...............  Messier-Bugatti........  C20194200                     1.97'' (50.0 mm)                
A310-300...............  ABS....................  5010995                       1.97'' (50.0 mm                 
A320...................  Messier-Bugatti........  C20225000                     1.97'' (50.0 mm)                
A320...................  Messier-Bugatti........  C20225200                     1.97'' (50.0 mm)                
A320...................  BFGoodrich.............  2-1526-2                      1.97'' (50.0 mm)                
A320...................  BFGoodrich.............  2-1526-3/-4                   2.68'' (68.0 mm)                
----------------------------------------------------------------------------------------------------------------
* S.C. represents ``Service Configured'' brakes, which are marked according to the instructions provided in the 
  brake manufacturer's Component Maintenance Manual.                                                            

    Note 1: Measuring instructions that must be revised to 
accommodate the new brake wear limits specified above can be found 
in Chapter 32-42-27 of the Airplane Maintenance Manual (AMM), in 
Chapter 32-32-( ) or 32-44-( ) of the brake manufacturer's Component 
Maintenance Manual (CMM), or in certain service bulletins (SB), as 
listed below:

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                Date/Revision (or later 
               Brake manufacturer                             Part No.                          Document/chapter                      revisions)        
--------------------------------------------------------------------------------------------------------------------------------------------------------
For Model A300-B2-100 Series Airplanes:                                                                                                                 
    Messier-Bugatti............................  286349-115                         CMM 32-42-27                              Apr. 1991.                
    Messier-Bugatti............................  286349-116                         CMM 32-42-27                              Apr. 1991.                
    BFGoodrich.................................  2-1449 & S.C.                      CMM 32-44-37                              Jan. 1993.                
                                                 .................................  SB 567 (2-1449-32-4)                      Jan. 30, 1993.            
For Model A300-B4-100 Series Airplanes:                                                                                                                 
    ALS (Bendix)...............................  2606802-3                          CMM 32-42-02                              Sept. 1993.               
                                                 2606802-4                          SB 2606802-32-003                         Mar. 31, 1993.            
                                                 2606802-5 & S.C.                                                                                       
    BFGoodrich.................................  2-1449 & S.C.                      CMM 32-44-37                              Jan. 1993.                
                                                                                    SB 567 (2-1449-32-4)                      Jan. 30, 1993.            
For Model A300-B4-200 and A300-600 Series                                                                                                               
 Airplanes:                                                                                                                                             
    ALS (Bendix)...............................  2607932-1 & S.C.                   CMM 32-42-27                              Sept. 1993.               
                                                                                    SB 2607932-32-002                         Mar. 31, 1993 & Revision  
                                                                                                                               1, dated.                
                                                                                                                              Oct. 1, 1993.             
For Model A300-B4-600R Series Airplanes:                                                                                                                
    Messier-Bugatti............................  C20210000 & C20210200              Airbus SB 470-32-675                      Apr. 6, 1990.             
For Model A310-200 Series Airplanes:                                                                                                                    
    ALS (Bendix)...............................  2606822-1 & S.B.                   CMM 32-42-03                              Sept. 1993.               
                                                                                    SB 2606822-32-002                         Mar. 31, 1993.            
For Model A310-300 Series Airplanes:                                                                                                                    
    Messier-Bugatti............................  C20225000-& C20225200              Airbus SB-470-32-675                      Apr. 6, 1990.             
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (2) Incorporate into the FAA-approved maintenance inspection 
program the maximum brake wear limits specified in paragraph (a)(1) 
of this AD.

    Note 2: Once an operator has complied with the requirements of 
this AD, paragraphs (a)(1) and (a)(2) of this AD do not require that 
operators subsequently record accomplishment of this AD each time a 
brake is inspected or overhauled in accordance with that operator's 
FAA-approved maintenance inspection program.

    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (c) Special flight permits may be issued in accordance with 
Secs. 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.
    (d) This amendment becomes effective on January 23, 1995.

    Issued in Renton, Washington, on December 14, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-31179 Filed 12-21-94; 8:45 am]
BILLING CODE 4910-13-U