The Aircraft Owners and Pilots Association (AOPA), representing the aviation interests of more than 350,000 pilots and aircraft owners, submits the following comments to Notice of Proposed Rulemaking (NPRM) 98-CE-121-AD. The NPRM proposes to supercede AD 98-05-04, expand the maintenance actions required by this Airworthiness Directive (AD) to all American Champion Aircraft (ACAC) 7,8, and 11 series airplanes, and incorporate alternative methods of accomplishing required actions.
AOPA thanks the FAA for making an effort to coordinate this rulemaking effort with various industry organizations, including AOPA and the Citabria Owners Group (COG). Although not perfect, the actions specified in this NPRM are an excellent example of how the FAA and the aviation community can work together to reach sensible and affordable solutions to legitimate airworthiness concerns.
However, AOPA believes that the AD, as proposed, fails to address all of the concerns of affected aircraft owners and the general aviation community. Particularly, AOPA is concerned with the lack of service instructions detailing the procedure to be utilized when conducting the proposed alternative inspection. Furthermore, AOPA is concerned with the broad scope of the inspections required by the proposed AD. Through contacts with COG and other individuals with considerable ACAC operational and maintenance experience, it is evident that the areas of inspection can be narrowed considerably without degrading the effectiveness of the inspection.
Instructions for Conducting Alternative Inspection:
The alternative inspection procedure (utilizing a Bend-A-Light® and telescoping inspection mirrors) is an effective alternative to installing multiple inspection holes on the upper and lower wing surfaces. However, the AD and referenced service material fail to detail how this inspection is to be conducted.
AOPA holds that it is in the best interest of aviation safety to provide aircraft mechanics with all information necessary to safely and correctly conduct any inspection required by an AD. Consequently, AOPA recommends that the FAA utilize one of the below listed options to ensure that aircraft mechanics receive adequate guidance for conducting the alternative inspection procedure.
Scope of Required Inspection:
As previously stated, AOPA has learned through contacts with organizations and individuals with considerable ACAC operational and maintenance experience, that the proposed inspections may be much too broad in scope. An inspection of the entire length of the spar for compression cracks is not necessary. Field experience shows that it is possible for cracks to propagate along the entire length of the wing spar. However, individuals with considerable ACAC service experience indicate that, invariably, compression cracks will first appear in the area between the ribs at the point where the strut attaches to the wing, including and immediately inboard/outboard of the spar doubler plates.
To address this concern, AOPA recommends that the scope of the wing spar inspection required by this AD be limited to the area between the ribs at the point where the strut attaches to the wing, including and immediately inboard/outboard of the spar doubler plates.
In summary, AOPA holds that it is in the interest of aviation safety to provide adequate instructions for compliance with required AD actions. Consequently, we recommend that the FAA take the necessary steps to ensure that; 1) instructions for completion of compliance actions are included in the text of this AD; or 2) information indicating where to obtain instructions to complete the alternative inspection procedure is included in the appropriate section of this AD.
Further, AOPA holds that the scope of the proposed wing spar inspection is much too broad. To remedy this, AOPA proposes that the scope of the required inspections be limited to the area of the wing spar where compression cracks are likely to first propagate.
Again, AOPA thanks the FAA for coordinating the actions specified by this AD with the aviation community. Coordination efforts, such as this one, better serve the aviation community and the non-flying public as they utilize the wealth of operational knowledge and experience of aircraft type-clubs and ownerï¿½s organizations. Continuation of these efforts will increase the overall quality and affordability of AD compliance actions, streamline the FAAï¿½s AD development process, increase the aviation communityï¿½s awareness of legitimate airworthiness concerns, and strengthen the relationship and communication between the FAA and the general aviation community.
Thank you for your time and consideration in this matter. AOPA stands ready to assist the FAA in reconsidering the actions proposed by this AD.
Dennis E. Roberts
Vice President/Executive Director
Government &Technical Affairs