[Federal Register Volume 61, Number 48 (Monday, March 11, 1996)]
[Rules and Regulations]
[Pages 9607-9611]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-5689]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-277-AD; Amendment 39-9537; AD 96-06-01]


Airworthiness Directives; Boeing Model 757 Series Airplanes 
Equipped With Abex Spoiler Actuators

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to Boeing Model 757 series airplanes that are equipped with 
certain Abex spoiler actuator electro-hydraulic servo valves (EHSV) 
installed in Abex spoiler actuators. This action requires a one-time 
inspection of the spoiler actuator to determine if a suspect EHSV is 
incorrectly installed, and replacement of the EHSV, if necessary. This 
amendment is prompted by reports that a bias spring in the Abex EHSV of 
certain Abex spoiler actuators has been found to be incorrectly 
installed. The actions specified in this AD are intended to prevent a 
significant control upset of the airplane as a result of problems 
associated with an incorrectly installed EHSV in the spoiler actuator 
assembly.

DATES: Effective March 26, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before May 10, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-277-AD, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056.
    Information concerning this AD action may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Don Eiford, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington; 
telephone (206) 227-2788; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports that a bias 
spring in the Abex electro-hydraulic servo valve 

[[Page 9608]]
(EHSV) in certain Abex spoiler actuators that are installed on certain 
Boeing Model 757 series airplanes has been found to be incorrectly 
installed. One operator received three valves on which the bias spring 
was installed on the wrong side of the EHSV second stage spool. 
Investigation revealed that the valves had been assembled incorrectly 
during repair at a non-U.S. repair facility. The subject EHSV's are 
Abex P/N 72196, Boeing Specification S251N116-1, Model 410-1870.
    If the jet pipe in the first stage of the EHSV is plugged, or if 
the differential pressure between the extend and retract ports 
pressurized by the jet pipe is inadequate, an incorrectly installed 
bias spring on the second stage spool would cause the spoiler to be 
driven into the ``deploy'' position. Such inadvertent spoiler 
deployment would result in the airplane experiencing a rolling moment. 
If the airplane is already banked or is at a low altitude, or if the 
crew does not respond rapidly enough to control the uncommanded roll, a 
significant control upset of the airplane could result.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to prevent the occurrence of a significant control upset 
of the airplane due to problems associated with suspect EHSV's in the 
spoiler actuator. This AD requires a one-time inspection of the Abex 
EHSV on the spoiler actuator to determine if a suspect valve is 
incorrectly installed; if so, the EHSV must be replaced.
    None of the Model 757 series airplanes affected by this action are 
on the U.S. Register. All airplanes included in the applicability of 
this rule currently are operated by non-U.S. operators under foreign 
registry; therefore, they are not directly affected by this AD action. 
However, the FAA considers that this rule is necessary to ensure that 
the unsafe condition is addressed in the event that any of these 
subject airplanes are imported and placed on the U.S. Register in the 
future.
    Should an affected airplane be imported and placed on the U.S. 
Register in the future, it would require approximately 1 work hour to 
accomplish the required actions, at an average labor charge of $60 per 
work hour. Based on these figures, the cost impact of this AD would be 
$60 per airplane.
    Since this AD action does not affect any airplane that is currently 
on the U.S. register, it has no adverse economic impact and imposes no 
additional burden on any person. Therefore, notice and public 
procedures hereon are unnecessary and the amendment may be made 
effective in less than 30 days after publication in the Federal 
Register.

Comments Invited

    Although this action is in the form of a final rule and was not 
preceded by notice and opportunity for public comment, comments are 
invited on this rule. Interested persons are invited to comment on this 
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 under the caption 
ADDRESSES. All communications received on or before the closing date 
for comments will be considered, and this rule may be amended in light 
of the comments received. Factual information that supports the 
commenter's ideas and suggestions is extremely helpful in evaluating 
the effectiveness of the AD action and determining whether additional 
rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-277-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

96-06-01  Boeing: Amendment 39-9537. Docket 95-NM-277-AD.

    Applicability: Model 757 airplanes, certificated in any 
category, that are equipped with Abex spoiler actuators having Abex 
electro-hydraulic servo valves (EHSV), part number 72196, with the 
serial numbers listed in Table 1 of this AD:

                                 Table 1                                
------------------------------------------------------------------------
                                 Boeing order                           
       EHSV serial No.              No.*-            Shipment date*     
------------------------------------------------------------------------
AH-0001......................  C716657........  8 November 1991.        
AH-0002......................  C716657........  8 November 1991.        
AH-0003......................  C727995........  25 August 1994.         
AH-0004......................  C727995........  25 August 1994.         
AH-0005......................  C727995........  25 August 1995.         
AH-0006......................  C727995........  25 August 1995.         
AH-0007......................  C727995........  25 August 1995.         
13...........................  C731181........  12 June 1995.           
49...........................  C730878........  01 June 1995.           
61...........................  C727955........  13 September 1994.      
131..........................  C708905........  13 November 89.         
233..........................  C727730........  17 June 1994.           
241..........................  C731540........  13 September 1995.      
260..........................  C727955........  13 September 1994.      
279..........................  C728298........  02 September 1994.      
275..........................  C727880........  24 June 1994.           
308..........................  C725421........  01 December 1993.       
329..........................  C727711........  17 June 1994.           
347..........................  C727518........  14 June 1994.           
401..........................  C728298........  05 September 1994.      
407..........................  C727730........  17 June 1994.           
427..........................  C731181........  03 July 1995.           

[[Page 9609]]
                                                                        
450..........................  C731181........  03 July 1995.           
445..........................  C706627........  22 February 89.         
457..........................  C731663........  12 September 1995.      
456..........................  C728887........  28 November 1994.       
463..........................  C731435........  21 August 1995.         
484..........................  C727748........  22 June 1994.           
515..........................  C727745........  24 June 1994.           
569..........................  C728290........  05 September 1994.      
579..........................  C724176........  14 September 1993.      
611..........................  C727955........  14 September 1994.      
607..........................  C727997........  20 July 1994.           
647..........................  C728459........  10 October 1994.        
726..........................  C731096........  04 September 1995.      
725..........................  C729525........  19 December 1994.       
819..........................  C728135........  03 August 1994.         
890..........................  C726803........  06 April 1994.          
874..........................  C730890........  26 April 1995.          
912..........................  C727977........  04 August 1994.         
991..........................  C713602........  10 December 90.         
998..........................  C731477........  4 September 1995.       
1022.........................  C708905........  13 November 89.         
1023.........................  C708905........  13 November 89.         
1072.........................  C709166........  14 November 89.         
1148.........................  C730192........  13 March 1995.          
1175.........................  C723278........  05 August 1993.         
1227.........................  C728303........  31 August 1994.         
1283.........................  C731833........  04 September 1995.      
1487.........................  C728549........  04 October 1994.        
1655.........................  C728442........  28 November 1994.       
1780.........................  C726757........  06 April 1994.          
1807.........................  C728669........  29 September 1994.      
1862.........................  C727625........  17 June 1994.           
1929.........................  C727977........  04 August 1994.         
1986Z........................  C727730........  17 June 1994.           
2017Z........................  C725411........  24 November 1993.       
2034.........................  C727730........  17 June 1994.           
2073.........................  C731272........  12 September 1995.      
2125.........................  C725713........  12 January 1994.        
2220.........................  C729735........  29 March 1995.          
2334.........................  C727730........  17 June 1994.           
2348.........................  C727730........  17 June 1994.           
2426.........................  C731623........  12 July 1995.           
------------------------------------------------------------------------
*The Boeing Order Number and Shipment Date are included in this listing 
  to enable operators to review their records in order to determine if a
  suspect EHSV has been ordered, and if, or where, it has been installed
  on an airplane.                                                       


    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
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 request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a significant control upset of the airplane due to 
problems associated with incorrectly assembled Abex electro-
hydraulic servo valves (EHSV) on certain Abex spoiler actuators, 
accomplish the following:
    (a) Within 6 months after the effective date of this AD, perform 
the following procedure:
    (1) While the airplane is on the ground, extend the flaps to 40 
degrees. and visually inspect the spoiler actuator EHSV assembly to 
determine the location of the second stage bias spring end cap 
assembly.
    (2) If the second stage bias spring cap assembly is on the aft 
or lower side of the EHSV assembly, prior to further flight, replace 
the EHSV, having Abex part number 72196, with a serviceable unit in 
accordance with the airplane maintenance manual.

    Note 2: To be correctly positioned, the second stage bias spring 
cap assembly should be on the upper or forward side of the EHSV 
assembly. Appendix 1 of this AD provides a visual representation of 
the correct positioning of the EHSV assembly.

    (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 3: 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 
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.
    (d) This amendment becomes effective on March 26, 1996.

BILLING CODE 4910-13-U

[[Page 9610]]


Appendix 1

[GRAPHIC] [TIFF OMITTED] TR11MR96.004


[[Page 9611]]

BILLING CODE 4910-13-C
    Issued in Renton, Washington, on March 5, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-5689 Filed 3-8-96; 8:45 am]
BILLING CODE 4910-13-U