Discussion
What events have caused this AD? The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified the FAA that an unsafe condition may exist on certain OMF Model OMF-100-160 airplanes. The LBA reports that the manufacturer received a report of cracks in the outside fuselage tube that supports the main landing gear leg. Further investigation revealed that one manufacturer of fuselage tubes used out-of-design dimensions for the tube elements.
What is the potential impact if FAA took no action? Cracks in the outside tube of the main landing gear leg, if not detected, corrected, and prevented, could result in structural failure of the fuselage tubing assembly. This failure could lead to loss of control of the airplane.
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 OMF Model OMF-100-160 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 18, 2004, (69 FR 51206). The NPRM proposed to detect, correct, and prevent future cracks in the outside tube of the main landing gear leg. These cracks could result in structural failure of the fuselage tubing assembly and lead to loss of control of the airplane.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in developing this AD. We received no comments on the proposal or on the determination of the cost to the public.
Conclusion
What is FAA's final determination on this issue? We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:
--Are consistent with the intent that was proposed in the NPRM for correcting the unsafecondition; and
--Do not add any additional burden upon the public than was already proposed in the NPRM.
Changes to 14 CFR Part 39--Effect on the AD
How does the revision to 14 CFR part 39 affect this AD? On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Costs of Compliance
How many airplanes does this AD impact? We estimate that this AD affects 11 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 accomplish the inspections:
Labor cost
Parts cost
Total cost per airplane
Total cost onU.S. operators
Inspection for cracks - 2 workhours est. $65 per hour = $130
N/A
$130
$1,430.
Inspection for inadequate thickness of tubing that supports the main landing gear leg - 2 workhours est. $65 per hour = $130.
N/A
130
OMF will cover the cost for the special inspection.
We estimate the following costs to accomplish any necessary repairs that would be required based on the results of these proposed inspections. We have no way of determining the number of airplanes that may need this repair:
Labor cost
Parts cost
Total cost per airplane
85 workhours x $65 per hour = $5,525
None per manufacturer
$5,525
Regulatory Findings
Will this AD impact various entities? We have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.
Will this AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this AD:
1. Is not a "significant regulatory action" under Executive Order 12866;
2. Is not a "significant rule" under the 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.
We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include "Docket No. 2004-CE-67-AD" in your request.
This rulemaking is promulgated under the authority in Subtitle VII, Part A, Subpart III, Section 44701, General requirements. Under that section, the FAA is charged with prescribing minimum standards required in the interest of safety for the design of aircraft. This regulation is within the scope of that authority since it corrects an unsafe condition in the design of the aircraft caused by cracks in the outside tube of the main landing gear leg.
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.
39.13 [Amended]
2. FAA amends 39.13 by adding a new AD to read as follows: