Discussion
What events have caused this AD? The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, recently notified FAA that an unsafe condition may exist on all SOCATA Models TB 9, TB 10, TB 20, TB 21, and TB 200 airplanes that do not have factory Modification 165 incorporated on the front seats. The DGAC reports cases where the seat pan interfered with the front seat locking mechanism. Interference with the seat locking mechanism could result in uncontrolled movement of the front seats.
This condition does not affect airplanes with factory Modification 165, any edition, incorporated. This modification consists of cutting a slot in the solid metal seat pan to eliminate the interference.
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 SOCATA--Groupe Aerospatiale (SOCATA) Models TB 9, TB 10, TB 20, TB 21, and TB 200 airplanes that do not have factory Modification 165, any edition, incorporated on the front seats. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 24, 2001 (66 FR 44556). The NPRM proposed to require you to modify the front seat configuration.
What is the potential impact if FAA took no action? The actions specified by this AD are intended to eliminate the potential for the front seats to inadvertently unlock from their fixed positions. Such uncontrolled movement could prevent the pilot from making the necessary flight maneuvers to control the airplane.
Was the public invited to comment? The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment:
Comment Issue No. 1: Manufacturer Estimates 36 Aircraft in the U.S. Fleet Are Affected by the Proposed ADWhat is the commenter's concern? The AD affects only certain models of seats; commenter estimates that 36 aircraft in the U.S. were affected by the AD. The commenter wants FAA to reflect this in the Cost Impact section.
What is FAA's response to the concern? The FAA agrees with the manufacturer that this initial estimate is correct. However, it is possible that owner/operators might have had modifications made to the aircraft later that make them subject to the AD. The FAA will note that this AD possibly affects 125 aircraft in the U.S. registry.
Comment Issue No. 2: FAA Better Identify Seats Affected by the AD
What is the commenter's concern? One commenter states that only seats with solid metal seat pans are affected by this AD; seats with a mesh seat pan are not affected. The commenter recommended that FAA make it clear in the AD what seats are affected.
What is FAA's response to the concern? The FAA agrees with the commenter and will clearly identify that onlysolid metal seat pans are affected by the AD.
FAA's Determination
What is FAA's final determination on this issue? We carefully reviewed all available information related to the subject presented above and determined that air safety and the public interest require the adoption of the rule as proposed except for the changes discussed above and minor editorial questions. We have determined that these changes and 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 possibly affects 125 airplanes in the U.S. registry. Of these 125 airplanes, 36 had the affected seats installed at the manufacturer. The other 89 airplanes could have had these seats installed since manufacture.
What is the cost impact of this AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the modification:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
5 workhours x $60 per hour = $300.
$58 ($29 per seat, 2 seats per airplane).
$358.
$358 x 125 = $44,750.
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: