Discussion
What Events Have Caused This AD?
The FAA has received reports of flap extension/retraction system failures on Raytheon Model 1900D airplanes. The failures occurred when the inner flexible shaft ends separated or disengaged. One of these failures resulted in an asymmetric flap condition when the flap safety switch failed to function properly.
The flap flexible shafts are designed to carry more torque in one direction than the other. If installed on the wrong side of the airplane, the excessive torque load leads to these failures. Raytheon informed us that the flap flexible shafts may have been installed on the wrong side of the airplane on certain Beech Models 1900, 1900C, and 1900D airplanes.
What Are the Consequences if the Condition Is Not Corrected?
Flap extension/retraction failures caused by incorrectly configured flap flexible shaft assemblies could result in loss of flap function or an asymmetric flap condition during flight if the flap safety switch fails to function properly.
Has FAA Taken Any Action to This Point?
The FAA 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 Raytheon Beech Models 1900, 1900C, and 1900D airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on June 5, 2001 (66 FR 30093). The NPRM proposed to require you to inspect the inner flexible (drive) shaft of all four flap flexible shaft assemblies for the correct diagonal wrap and the correct installation; and replace any flap flexible shaft assembly that has an incorrect diagonal wrap or incorrect installation.
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'sFinal Determination on This Issue?
After careful review of all available information related to the subject presented above, FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. We determined that these minor corrections:
--Will not change the meaning of the AD; and
--Will not add any additional burden upon the public than was already proposed.
Cost Impact
How Many Airplanes Does This AD Impact?
The FAA estimates that this AD affects 205 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
2 workhours x $60 per hour = $120
No parts required for the inspection
$120 per airplane
$24,600
We estimate the following costs to accomplish any necessary replacements that will be required based on the results of the inspection. We have no way of determining the number of airplanes that may need such replacements.
Labor cost
Parts cost
Cost per flap shaft
8 workhours per flap shaft x $60 per hour = $480.
$232 per flap shaft
$712 per flap shaft (total of four per airplane).
The manufacturer will provide warranty credit for labor and parts to the extent noted under the Warranty Credit section of Raytheon Mandatory Service Bulletin SB 27-3397, Issued: January, 2001.
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 part39) 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: