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 Dornier Models 228-100, 228-101, 228- 200, 228-201, 228-202, and 228-212 airplanes. The LBA reports two occurrences of cracks found around the riveted joints of the leading edge skin and ribs of the horizontal stabilizer during an inspection. The LBA reports that the cracks are caused by corrosion and material fatigue.
What Is the Potential Impact if FAA Took No Action?
If this condition is not detected and corrected, in-flight separation of the horizontal stabilizer skin could result with consequent 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 Dornier Models 228-100, 228-101, 228-200, 228-201, 228-202, and 228-212 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 21, 2001 (66 FR 43815). The NPRM proposed to require you to inspect the horizontal stabilizer ribs for cracks; inspect the horizontal stabilizer skin for cracks and damage around the riveted joints; repair or replace any cracked ribs; and repair any damaged skin.
Is There a Modification I Can Incorporate Instead of Repetitively Inspecting the Horizontal Stabilizer Structure?
The FAA has determined that long-term continued operational safety would be better assured by design changes that remove the source of the problem rather than by repetitive inspections or other special procedures. With this in mind, we will continue to work with Dornier in collecting information and in performing fatigue analysis to determine whether a future design change may be necessary.
Was the Public Invited To Comment?
The FAA encouragedinterested 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 14 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
4 workhours x $60 per hour = $240
No parts required for the inspection
$240
$240 x 14 = $3,360
We have no method of determining the number of repetitive inspections each owner/operator will incur over the life of each of the affected airplanes so the cost impact is based on the initial inspection.
We have no method of determining the number of repairs or replacements each owner/operator will incur over the life of each of the affected airplanes based on the results of the inspections. We have no way of determining the number of airplanes that may need such repair. The extent of damage may vary on each airplane.
Compliance Time of This AD
What Is the Compliance Time of This AD?
The compliance time of this AD will be to accomplish the initial inspection "within the next 100 hours time-in-service (TIS) after the effective date of this AD", repetitive inspections at "intervals not to exceed 100 hours TIS", and any necessary repairs or replacements "prior to further flight after the inspection."
Why Is the Initial Inspection Compliance Time of the German AD Different From the Initial Inspection Compliance Time in This AD?
The German AD requires (on Dornier Models 228-100, 228-101, 228- 200, 228-201, 228-202, and 228-212 airplanes registered in Germany) the initial inspection within the next 10 flight hours. This is the compliance time specified in the service information. We do not have justification to require the initial inspection within 10 flight hours. We use a compliance time such as this when we have identified an urgent safety of flight situation. We believe that 100 hours TIS will give the owners/operators of the affected airplanes enough time to have the initial inspection and repairs and/or replacements accomplished without compromising the safety of the airplanes.
By accomplishing both the initial inspection andreplacement at the same time, the owners/operators of the affected airplanes only have their airplanes out of service once instead of twice.
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: