[Federal Register Volume 61, Number 35 (Wednesday, February 21, 1996)] [Rules and Regulations] [Pages 6503-6505] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 96-3262] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 95-NM-34-AD; Amendment 39-9517; AD 96-04-05] Airworthiness Directives; Airbus Model A300-B2 and -B4 Series Airplanes Equipped with General Electric CF6-50 Series Engines or Pratt & Whitney JT9D-59A Engines AGENCY: Federal Aviation Administration, DOT. ACTION: Final rule. ----------------------------------------------------------------------- SUMMARY: This amendment adopts a new airworthiness directive (AD) that is applicable to certain Airbus Model A300-B2 and -B4 series airplanes. This amendment requires an inspection to detect discrepancies of a certain thrust reverser control lever spring; an operational test to verify the integrity of the flight inhibition circuit of the thrust reverser system; and either the correction of discrepancies or deactivation of the associated thrust reverser. It also provides for an optional terminating action. This amendment is prompted by a report that, due to broken and deformed thrust reverser control lever springs, an uncommanded movement of the thrust reverser lever to the unlock position and a ``reverser unlock'' amber warning occurred on one airplane. The actions specified by this AD are intended to detect such broken or deformed control lever springs before they can lead to uncommanded deployment of a thrust reverser and subsequent reduced controllability of the airplane. DATES: Effective March 22, 1996. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of March 22, 1996. ADDRESSES: The service information referenced in this AD may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 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: Charles Huber, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2589; fax (206) 227-1149. 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 Model A300-B2 and - B4 series airplanes was published in the Federal Register on April 3, 1995 (60 FR 16813). That action proposed to require a mechanical integrity inspection to detect discrepancies of the thrust reverser control lever spring having part number (P/N) A2791294520000, and an operational test to verify the integrity of the flight inhibition circuit of the thrust reverser system. It also requires the correction of discrepancies or deactivation of the associated thrust reverser. 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 notes that the Description section of the preamble to the notice states that ``* * * uncommanded movement of the thrust reverser lever to the unlock position and a `reverser unlock' amber warning occurred.'' The commenter suggests, to be consistent with the current industry definition, a more accurate description of what caused the unsafe condition is ``inadvertently commanded deployment [of the thrust reverser].'' The FAA does not concur. The FAA has reviewed the relevant data available, and finds no basis to support the commenter's suggestion that the thrust reverser was ``commanded'' to deploy. The FAA finds that the pilot did not command the thrust reverser to deploy, nor did the pilot inadvertently deploy the thrust reverser. Additionally, this commenter requests clarification of certain statements made in the Discussion section of the preamble to the notice. The commenter asks whether the reported incident occurred when the airplane was on the ground or in flight. The FAA concurs that some clarification is necessary. The incident occurred on the ground during a training flight where a simulated engine-out condition was performed. Since the Discussion section is not restated in this final rule, no change to the final rule is necessary as a result of this clarification. The same commenter requests that the proposed rule be revised to require repetitive inspections of the thrust reverser control lever spring, and a final corrective action. The commenter asserts that, since the notice indicates that the unsafe condition is ``* * * likely to develop'' on affected airplanes, it would seem reasonable to require replacement of the spring, regardless of the condition of the spring at the initial inspection. Additionally, until the spring is replaced, it should be repetitively inspected, since it is not clear if the root cause of the problem is a design or assembly defect, or if it is time- related. The FAA concurs partially. [[Page 6504]] Since issuance of the notice, Airbus has issued Service Bulletin A300- 78-0015, dated May 17, 1995, which describes procedures for replacement of the left and right control levers of the thrust reverser with a new control lever equipped with a new spring. The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, approved this service bulletin. The FAA finds that the replacement specified in that service bulletin may be provided as an optional terminating action for the requirements of this final rule. Therefore, the FAA has added a new paragraph (b) to the final rule to provide for this option. Additionally, the FAA is considering additional rulemaking to require repetitive inspections of the thrust reverser lever spring, as well as to mandate the eventual replacement of the thrust reverser control lever with the new control lever. However, the planned compliance time for this repetitive inspection and replacement is sufficiently long so that notice and public comment will be practicable. 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 estimates that 21 airplanes of U.S. registry will be affected by this AD, that it will take approximately 6 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $55 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $8,715, or $415 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. 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 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: 96-04-05 Airbus Industrie: Amendment 39-9517. Docket 95-NM-34-AD. Applicability: Model A300-B2 and B-4 series airplanes, equipped with General Electric CF6-50 series engines or Pratt & Whitney JT9D- 59A engines; certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (c) 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 the detection of broken or deformed thrust reverser control lever springs that could lead to uncommanded deployment of a thrust reverser and subsequent reduced controllability of the airplane, accomplish the following: (a) Within 500 flight hours after the effective date of this AD, perform a mechanical integrity inspection to detect discrepancies of the thrust reverser control lever spring having part number (P/N) A2791294520000, and an operational test to verify the integrity of the flight inhibition circuit of the thrust reverser system, in accordance with Airbus All Operators Telex AOT 78-03, Revision 1, dated July 20, 1994. (1) If no discrepancies are detected, no further action is required by this AD. (2) If the control lever spring is found broken or out of tolerance, prior to further flight, replace it with a new control lever spring or deactivate the associated thrust reverser in accordance with the AOT. (3) If the flight inhibition circuit of the thrust reverser system fails the operational test, prior to further flight, determine the origin of the malfunction, in accordance with the AOT. (i) If the origin of the malfunction is identified, prior to further flight, repair the flight inhibition circuit in accordance with the AOT. (ii) If the origin of the malfunction is not identified, prior to further flight, replace the relay having P/N 125GB or 124GB, and repeat the operational test, in accordance with the AOT. If the malfunction is still present, prior to further flight, inspect and repair the wiring in accordance with the AOT. If the malfunction is still present following the inspection and repair, prior to further flight, deactivate the associated thrust reverser in accordance with the AOT. (b) Replacement of the left and right control levers of the thrust reverser with a new control lever equipped with a new spring, in accordance with Airbus Service Bulletin A300-78-0015, dated May 17, 1995, constitutes terminating action for the requirements of this AD. (c) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113. (d) 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. (e) The actions shall be done in accordance with Airbus All Operators Telex AOT 78-03, Revision 1, dated July 20, 1994. 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 Airbus [[Page 6505]] Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 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. (f) This amendment becomes effective on March 22, 1996. Issued in Renton, Washington, on February 8, 1996. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 96-3262 Filed 2-20-96; 8:45 am] BILLING CODE 4910-13-P