Discussion
What events have caused this AD? The Civil Aviation Safety Authority (CASA), which is the airworthiness authority for Australia, recently notified FAA that an unsafe condition may exist on all ASTA Models N22B and N24A airplanes. The CASA reports several incidents of ailerons incurring damage during flight. Extensive tests and
analysis revealed that the cause of the damage to the ailerons is a result of operation outside approved limits and undetected pre-existing damage. This condition causes the aileron to flutter as well as damage and failure.
The CASA lowered the operational limits of the affected airplanes in order to prevent damage from occurring. Additional reports of aileron flutter have been received even when operating within these lower approved limits.
As a precautionary measure, the CASA is further restricting flight operations.
What is the potential impact if FAA took no action? If this condition is not corrected, it could result in aileron failure. Such failure could lead to 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 all ASTA Models N22B and N24A airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 18, 2003 (68 FR 49390). The NPRM proposed to visually inspect the ailerons for damage and replace if necessary; adjust the engine power levers aural warning microswitches; set flap extension and flap down operation limitations; and fabricate and install cockpit flap extension and flap down operation restriction placards.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in the development of this AD. We received no comments on the proposal or on the determination of the cost to the public.
ConclusionWhat 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:
--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.
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 10 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 inspection:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
1 workhour x $60 per hour = $60
Not applicable
$60
10 x $60 = $600
We estimate the following costs to accomplish any necessary replacements that would be required based on the results of this inspection. We have no way of determining the number of airplanes that may need such repair/replacement:
Labor cost
Parts cost
Total cost per airplane
10 workhours x $60 per hour = $600
$1,250
$600 + $1,250 = $1,850
We estimate the following costs to accomplish the modifications:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
10 workhours x $60 per hour = $600.
$100
$700
$700 x 10 = $7,000
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 "AD Docket No. 2003-CE-21-AD" in your request.
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: