AD 97-06-10

This amendment supersedes Airworthiness Directive (AD) 91-14-14, which currently requires repetitively inspecting the main landing gear (MLG) "A" frame assemblies for cracks on Raytheon Aircraft Company (Raytheon) Model 76 airplanes (formerly referred to as Beech Model 76 airplanes), and replacing any assembly found cracked. AD 91-14-14 resulted from reports of fatigue cracks developing on the MLG "A" frame assemblies of the affected airplanes. Raytheon has developed improved design MLG "A" frame assemblies, and the Federal Aviation Administration (FAA) has determined that Model 76 airplanes with an improved design "A" frame assembly installed on both the left and right MLG should be exempt from AD 91-14-14. This action retains the requirement of repetitively inspecting the MLG "A" frame assemblies for cracks and replacing any cracked "A" frame assembly only for those Model 76 airplanes that do not have the improved design parts installed. The actions specified by this ADare intended to prevent MLG failure because of a cracked "A" frame assembly, which could result in loss of control of the airplane during landing operations.

Final rule

97-06-10 RAYTHEON AIRCRAFT COMPANY (formerly Beech Aircraft Corporation): Amendment 39-9967; Docket No. 94-CE-34-AD. Supersedes AD 91-14-14, Amendment 39- 7055. \n\n\tApplicability: Model 76 airplanes (serial numbers ME-1 through ME-437), certificated in any category, that do not have both a part number (P/N) 105-810023-75 (left) and P/N 105- 810023-76 (right) main landing gear (MLG) "A" frame assembly installed. \n\n\tNOTE 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 (e) 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. \n\n\tCompliance: Required initially within the next 50 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished (compliance with AD 91-14-14), and thereafter at intervals not to exceed 100 hours TIS. \n\n\tTo prevent MLG failure because of a cracked "A" frame assembly, which could result in loss of control of the airplane during landing operations, accomplish the following: \n\n\t(a)\tInspect, using both visual and dye penetrant methods, both the left and right MLG "A" frame assemblies for cracks in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Raytheon Mandatory Service Bulletin No. 2361, Revision III, dated June 1996. Pay particular attention to the tips of the gussets and the small corrosion treatment hole adjacent to the gusset. \n\n\t(b)\tIf any MLG "A" frame assembly is found cracked during any inspection required by this AD, prior to further flight, replace the assembly with one of the following in accordance with Chapter 32 of the Raytheon Model 76 Maintenance Manual: \n\n\t\t(1)\tA new MLG "A" frame assembly with the same P/N as that found cracked. The 100-hour TIS repetitive inspection requirement still applies when this design "A" frame is installed. \n\n\t\t(2)\tA P/N 105-810023-75 (left) or P/N 105-810023-76 (right) main MLG "A" frame assembly, as applicable. Repetitive inspections are no longer required on an MLG "A" frame assembly incorporating this design configuration. Repetitive inspections are still required on an MLG "A" frame assembly if it does not incorporate this improved design configuration. \n\n\t(c)\tInstalling both P/N 105-810023-75 (left) and P/N 105-810023-76 (right) MLG "A" frame assemblies eliminates the repetitive inspection requirement of this AD. \n\n\t(d)\tSpecial 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. \n\n\t(e)\tAn alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Wichita ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO. \n\n\t(f)\tThe inspection required by this AD shall be done in accordance with Raytheon Mandatory Service Bulletin No. 2361, Revision III, dated June 1996. 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 the Raytheon Aircraft Company, P.O. Box 85, Wichita, Kansas 67201-0085. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(g)\tThis amendment (39-9967) supersedes AD 91-14-14, Amendment 39-7055. \n\n\t(h)\tThis amendment becomes effective on May 16, 1997.

Events Leading to the Issuance of the This AD\n\tA proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to Raytheon Model 76 airplanes (formerly referred to as Beech Model 76 airplanes) was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 18, 1996 (61 FR 54368). The NPRM proposed to supersede AD 91-14-14 with a new AD that would retain the requirement of repetitively inspecting the MLG "A" frame assemblies for cracks and replacing any part found cracked, but would exempt those airplanes with both a P/N 105-810023-75 (left) and P/N 105-810023-76 (right) MLG "A" frame assembly installed. Accomplishment of the proposed repetitive inspections as specified in the NPRM would be in accordance with Raytheon Mandatory Service Bulletin No. 2361, Revision III, dated June 1996.\n\n\tThe NPRM was the result of Raytheon developing improved design MLG "A" frame assemblies, and the FAA determining that Model 76 airplanes with an improved design "A" frame assembly installed on both the left and right MLG should be exempt from AD 91-14-14.\n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.\n\nThe FAA's Determination\n\tAfter careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.\n\nCost Impact\n\tThe FAA estimates that 437 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 2 workhours per airplane to accomplish the requiredaction, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $52,440. These figures only take into account the cost of the required initial inspection; repetitive inspection costs and costs for replacing any cracked MLG "A" frame assemblies are not included in these figures. The FAA has no way of determining how many airplanes will have cracked MLG "A" frame assemblies or how many repetitive inspections each affected owner/operator will incur over the life of the airplane.\n\n\tThe only difference between this AD and AD 91-14-14 is that this AD exempts airplanes with the improved MLG "A" frame assemblies installed. Therefore, the cost impact of this AD is less than that already required by AD 91-14-14 because the FAA believes that some airplanes will have the improved MLG "A" frame assemblies installed.\n\nRegulatory Impact\n\tThe regulations adopted herein will not have substantialdirect 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.\n\n\tFor 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 copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption "ADDRESSES".\n\nList of Subjects in 14 CFR Part 39\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\nAdoption of the Amendment\n\tAccordingly, 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:\n\nPART 39 - AIRWORTHINESS DIRECTIVES\n\t1. The authority citation for part 39 continues to read as follows:\nAuthority: 49 USC 106(g), 40113, 44701.\n\n§ 39.13 (Amended)\n\t2. Section 39.13 is amended by removing Airworthiness Directive (AD) 91-14-14, Amendment 39-7055 (56 FR 29173, June 26, 1991), and by adding a new AD to read as follows: