Discussion
What Events Have Caused This AD?
Transport Canada, which is the airworthiness authority for Canada, notified FAA that an unsafe condition may exist on certain de Havilland Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes. Transport Canada reports numerous incidents of corrosion of the front fuselage struts. Further analysis of the front fuselage struts reveals that these parts are not life limited and incur corrosion and fatigue damage over time.
What Is The Potential Impact if FAA Took No Action?
Corrosion damage, if not detected and corrected, could result in failure of the front fuselage and possible reduced or 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 de Havilland Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on March 28, 2002 (67 FR 14886). The NPRM proposed to establish a life limit for the front fuselage struts and would require you to repetitively replace the front fuselage struts every 15 years or repetitively inspect the struts for corrosion or fatigue damage and replace when the damage exceeds a certain level.
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 354 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 replacement:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. Operators
108 workhours x $60 an hour = $6,480 per airplane
$2,352 per airplane
$8,832 per airplane per replacement
$3,126,528
Compliance Time of This AD
What Will Be the Compliance Time of This AD?
The replacement compliance time of this AD is "initially replace upon accumulating 15 years from the date of installation of the front fuselage struts or within the next 12 calendar months after the effective date of this AD, whicheveroccurs later, and thereafter at intervals not to exceed 15 years." If the repetitive inspection option is used, then the repetitive compliance time interval will be at 1 and 5 years depending on the method used (provided certain corrosion or damage limits are not exceeded).
Why Is the Compliance Time Presented in Calendar Time Instead of Hours Time-in-Service (TIS)?
The compliance of this AD is presented in calendar time instead of hours TIS. The need for establishing a life limit for the front fuselage struts as specified in this AD is the result of reports of corrosion found in this area on the affected airplanes. Corrosion can occur regardless of whether the aircraft is in operation. In order to ensure that the unsafe condition specified in this AD does not go undetected if the airplane was not in operation for an extended period of time, the compliance is presented in calendar time instead of hours TIS.
Regulatory Flexibility Determination and Analysis
What Are the Requirements of the Regulatory Flexibility Act?
The Regulatory Flexibility Act of 1980 was enacted by Congress to assure that small entities are not unnecessarily or disproportionately burdened by government regulations. This Act establishes "as principle of regulatory issuance that agencies shall endeavor, consistent with the objectives of the rule and of applicable statutes, to fit regulatory and informational requirements to the scale of the businesses, organizations, and governmental jurisdictions subject to regulation." To achieve this principle, the Act requires agencies to solicit and consider flexible regulatory proposals and to explain the rationale for their actions. The Act covers a wide range of small entities, including small businesses, not-for-profit organizations, and small governmental jurisdictions.
Agencies must perform a review to determine whether a proposed or final rule will have a significant economic impact on a substantial number of small entities.If the determination is that the rule will, the Agency must prepare a regulatory flexibility analysis as described in the RFA.
However, if an agency determines that a proposed or final rule is not expected to have a significant economic impact on a substantial number of small entities, section 605(b) of the RFA provides that the head of the agency may so certify and a regulatory flexibility analysis is not required. The certification must include a statement providing the factual basis for this determination, and the reasoning should be clear.
What Is FAA's Determination?
The FAA has determined that this AD could have a significant economic impact on a substantial number of small entities. However, we have determined that we should continue with this action in order to address the unsafe condition and ensure aviation safety.
You may obtain a copy of the complete Regulatory Flexibility Analysis (entitled "Final Regulatory Flexibility Analysis") that was prepared forthis AD from the Docket file at the location listed under the ADDRESSES section of this document.
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) could 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, 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: