[Federal Register Volume 62, Number 99 (Thursday, May 22, 1997)]
[Rules and Regulations]
[Pages 27941-27942]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-13467]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-201-AD; Amendment 39-10036; AD 97-11-07]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90-30 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all McDonnell Douglas Model MD-90-30 airplanes, that 
requires revising the Airworthiness Limitations Section of the 
Instructions for Continued Airworthiness [MD-90-30 Airworthiness 
Limitations Instructions (ALI)]. The revision will incorporate certain 
compliance times for inspections to detect fatigue cracking of 
principal structural elements (PSE) and to add PSE's to the ALI. This 
amendment is prompted by analysis of data that identified reduced 
initial inspection thresholds, reduced repetitive inspection intervals 
for PSE's, and other PSE's to be added to the ALI. The actions 
specified by this AD are intended to ensure that fatigue cracking of 
various PSE's are detected and corrected; such fatigue cracking could 
adversely affect the structural integrity of these airplanes.

EFFECTIVE DATE: June 26, 1997.

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.

FOR FURTHER INFORMATION CONTACT: Brent Bandley, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(562) 627-5237; fax (562) 627-5210.

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 all McDonnell Douglas Model MD-90-
30 airplanes was published in the Federal Register on March 7, 1997 (62 
FR 10490). That action proposed to require operators to revise the 
Airworthiness Limitations Section of the Instructions for Continued 
Airworthiness [MD-90-30 Airworthiness Limitations Instructions (ALI)]. 
The revision would incorporate certain compliance times for inspections 
to detect fatigue cracking of principal structural elements (PSE) and 
to add PSE's to the ALI.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the two comments received.
    Both commenters support the proposed rule.

Conclusion

    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.

Cost Impact

    There are approximately 15 McDonnell Douglas Model MD-90-30 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 11 airplanes of U.S. registry will be affected by this 
AD, that it will take approximately 1 work hour per airplane to 
accomplish the required actions, and that the average labor rate is $60 
per work hour. Based on these figures, the cost impact of the AD on 
U.S. operators is estimated to be $660, or $60 per airplane.
    The cost impact figure discussed above is 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.

[[Page 27942]]

Regulatory Impact

    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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

97-11-07  McDonnell Douglas: Amendment 39-10036. Docket 96-NM-201-AD.

    Applicability: All Model MD-90-30 airplanes, certificated in any 
category.

    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 (d) 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 ensure continued structural integrity of these airplanes, 
accomplish the following:
    (a) Within 180 days after the effective date of this AD, revise 
the Airworthiness Limitations Section of the Instructions for 
Continued Airworthiness [Airworthiness Limitations Instructions 
(ALI), McDonnell Douglas Report No. MDC-94K9000, dated November 
1994] to incorporate the Item, Location, and Inspection Interval of 
the following principal structural elements: This may be 
accomplished by inserting a copy of Revision 1 of the ALI, dated 
January 1995, or a copy of this AD into the ALI.

------------------------------------------------------------------------
                                                 Inspection interval (in
                                                        landings)       
          Item                  Location       -------------------------
                                                  Initial       Repeat  
------------------------------------------------------------------------
Item 53.30.02.3.........  Skin Panels, STA 237       60,000       11,000
                           to 1395 Fuselage                             
                           Skin in Constant                             
                           Section from                                 
                           Longeron 3 Left to                           
                           Longeron 3 Right.                            
Item 53.30.02.4.........  Skin Panels, STA 237       60,000       30,000
                           to 1395 Fuselage                             
                           Hoop Skin Splice in                          
                           Constant Section                             
                           from Longeron 5                              
                           Left to Longeron 5                           
                           Right.                                       
Item 54.10.04.1.........  Thrust Bulkhead,           15,000        4,500
                           Pylon--STA Yn                                
                           170.5--Rear Spar                             
                           and Engine Thrust                            
                           Support Fitting                              
                           (Upper and Lower).                           
------------------------------------------------------------------------

    (b) Within 180 days after the effective date of this AD, revise 
the Airworthiness Limitations Section of the Instructions for 
Continued Airworthiness [Airworthiness Limitations Instructions 
(ALI), McDonnell Douglas Report No. MDC-94K9000, dated November 
1994] to incorporate the Item, Location, and Inspection Interval of 
the following principal structural elements: This may be 
accomplished by inserting a copy of Revision 2 to the ALI, dated 
July 1996, or a copy this AD into the ALI.

------------------------------------------------------------------------
                                                 Inspection interval (in
                                                        landings)       
          Item                  Location       -------------------------
                                                  Initial       Repeat  
------------------------------------------------------------------------
Item 55.13.01.1.........  Plates/Skin--Upper         60,000        8,100
                           STA Xh 27.2 Left to                          
                           Xh 27.2 Right--                              
                           Upper Aft Skin                               
                           Plank with Integral                          
                           Stringers from Xh                            
                           7.234 to Xh 26.859.                          
------------------------------------------------------------------------

    (c) Except as provided in paragraph (d) of this AD: After the 
actions specified in paragraphs (a) and (b) of this AD have been 
accomplished, no alternative inspections or inspection intervals may 
be approved for the parts specified in paragraph (a) and (b) of this 
AD.
    (d) 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, Los Angeles 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, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (e) 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.
    (f) This amendment becomes effective on June 26, 1997.

    Issued in Renton, Washington, on May 16, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-13467 Filed 5-21-97; 8:45 am]
BILLING CODE 4910-13-U