Discussion
What Events Have Caused This AD?
The Austro Control GmbH (Austro Control), which is the airworthiness authority for Austria, recently notified FAA that an unsafe condition may exist on all Diamond Models H-36 "Dimona", HK 36 R "Super Dimona", HK 36 TC, HK 36 TS, HK 36 TTC, HK 36 TTC-ECO, HK 36 TTC-ECO (Restricted Category), and HK 36 TTS sailplanes. The Austro Control reports that during the preflight of one sailplane, the long aileron push rod was found to be broken. On several sailplanes, the aileron push control rods in both wings were found damaged due to contact or interference with the support for the aileron bellcrank.
What Is the Potential Impact If FAA Took No Action?
If the damaged aileron push control rods are not detected and corrected, the damage could result in failure of the aileron push rods and decreased control. Such failure could lead to aeroelastic flutter.
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 Diamond Models H-36 "Dimona", HK 36 R "Super Dimona", HK 36 TC, HK 36 TS, HK 36 TTC, HK 36 TTC-ECO, HK 36 TTC-ECO (Restricted Category), and HK 36 TTS sailplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on May 20, 2002 (67 FR 35459). The NPRM proposed to require you to inspect the long aileron push rods in both wings for damage and modify the push rods.
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 Sailplanes Does This AD Impact?
We estimate that this AD affects 45 sailplanes in the U.S. registry.
What Is the Cost Impact of This AD on Owners/Operators of the Affected Sailplanes?
We estimate the following costs to accomplish the inspection:
Labor cost
Parts cost
Total cost per sailplane
Total cost on U.S. operators
1 workhour x $60 per hour = $60
None
$60
$60 x 45 = $2,700
We estimate the following costs to accomplish the modification:
Labor cost
Parts cost
Total cost per sailplane
Total cost on U.S. operators
2 workhours x $60 per hour = $120
$80
$200
$200 x 45 = $9,000Compliance Time of This AD
Why Is a Compliance Time of 10 Hours Time-in-Service (TIS) Used for the Inspection of the Long Aileron Push Rods?
Normally, FAA uses a 10-hour TIS compliance time for urgent safety of flight conditions. However, sailplane operation varies among operators. It might take operators between 3 months to 12 months or more to accumulate 10 hours TIS. For this reason, FAA has determined that the compliance time of this AD should be 10 hours TIS to ensure this condition is corrected in a timely manner but does not unduly penalize operators.
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: