Discussion
What Events Have Caused This AD?
The FAA has received reports of many incidents of fatigue cracks occurring on main landing gear torque knees. There have been at least four reports where the main landing gear separated from the airplane.
The cause of this problem is cumulative fatigue damage on the main landing gear torque knees.
What Is the Potential Impact if FAA Took No Action?
This condition, if not corrected, could result in the failure of the main landing gear while the airplane is in operation with consequent loss of control of the airplane during takeoff, landing, or other ground operations.
Has FAA Taken Any Action to This Point?
We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Raytheon Beech Models 65-90, 65-A90, 65-A90-1, 65-A90-4, B90, C90, C90A, E90, and H-90 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 27, 2001 (66 FR 44988). The NPRM proposed to require you to repetitively inspect the main landing gear upper torque knees and lower torque knees for evidence of fatigue cracks; and replace any torque knee with evidence of fatigue cracks.
Was the Public Invited to Comment?
The FAA encouraged interested persons to participate in the making of this amendment. We did not receive any comments on the proposed rule or on our determination of the cost to the public.
FAA's Determination
What is FAA's Final Determination on This Issue?
After careful review of all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. We have determined that these minor corrections:
--Provide the intent that was proposed in the NPRM for correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already proposed in the NPRM.
Cost Impact
How Many Airplanes Does This AD Impact?
We estimate that this AD affects 2,124 airplanes in the U.S. registry.
What Is the Cost Impact of This AD on Owners/Operators of the Affected Airplanes?
We estimate the following costs to inspect the landing gear torque knees:
Labor cost
Parts cost per airplane
Total cost per airplane
Total cost U.S. operators
20 workhours x $60 per hour = $1200
$50
$1,250
$1,250 x 2,124 = $2,655,000.
The manufacturer will allow warranty credit to the extent noted in the service bulletin.
These costs only take into account the costs of the initial inspection. We have no way of determining the number of repetitive inspections each owner/operator will incur over the life of the affected airplane.
We estimate the following costs to do any necessary torque knee replacements that would be required based on the resultsof the inspection. We have no way of determining the number of airplanes that may need such replacement:
Labor cost
Parts cost per airplane
Total cost per airplane
8 workhours x $60 per hour = $480
$3,286
$3,766
Regulatory Impact
Does This AD Impact Various Entities?
The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.
Does This AD Involve a Significant Rule or Regulatory Action?
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 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under 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. FAA amends Sec. 39.13 by adding a new AD to read as follows: