Mesa Airlines

The topic of this proposed AD, Functional Check of the Dielectric Properties of the Aluminum Loaded Primer and Enamel on the Wing Skin at Stn. Yw171.20 to Yw261.00, was first introduced as a by product of AD 2008-09-25. AD 2008-09- 25 required a revision to the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness to include Critical Design Configuration Control Limitations (CDCCL) specified in de Havilland Temporary Revision (TR) AWL 2-35 dated April 12, 2006, Part2, “Airworthiness Limitations List, “ of de Havilland Dash 8 Series 200 MPM, PSM 1-82-7. This task was then included in the AWL CDCCL MATRIX. The second time, the topic of this proposed AD, Functional Check of the Dielectric Properties of the Aluminum Loaded Primer and Enamel on the Wing Skin at Stn. Yw171.20 to Yw261.00, was in AD 2008-13-09. AD 2008-13-09 required a revision to the ALS of the Instructions for Continued Airworthiness to incorporate the fuel system limitations tasks identified in the de Havilland temporary revisions to Part 2, “Airworthiness Limitations List,” of the Dash 8 Series Maintenance Program Manuals, DHC-8-201, and DHC-8-202 airplanes AWL 2-43, dated August 31, 2007 Dash 8 Series 200 MPM, PSM 1-82-7, Part 2, “Airworthiness Limitations List”. AWL 2-43 outlines Fuel System Limitations tasks. Task Number FSL-07 - Functional Check of the Dielectric Properties of the Aluminum Loaded Primer and Enamel on the Wing Skin was given an Interval of 18000 flt hours or 108 months and repeat at 18000 flt hours – Initial Inspections with Threshold and Grace Period given in Table 2 of AD. Our Initial Inspections for FSL-07 were set at 6000 flt hours or 36 months with repeat inspections set at 18000 flt hours. NPRM 2009-NM-037-AD makes no mention of the task inclusion in either of the two above mentioned AD’s. Furthermore, NPRM 2009-NM-037-AD has compliance times set for 18 months after the effective date of the AD. With this time constraint we will have to move these inspections forward approx. 254 days. We feel this will cause undo stress upon the Airline as task FSL-07 is set to correspond with heavy maintenance checks and the NPRM time constraint will require massive rescheduling. As mentioned in the paragraph above, the inclusion of task FSL-07 offered a threshold and grace period. Can the time constraint for the NPRM be set to correspond with the inclusion of task FSL-07? NPRM 2009-NM-037-AD is to be accomplished IAW SB 8-57-46 Rev. A, dated February 6, 2009. Paragraph 3 ACCOMPLISHMENT INSTRUCTIONS, of stated SB, has the following statement. NOTE: The maintenance procedure that follows is a fuel tank safety – critical item and is classified as Critical Design Configuration Control Limitation (CDCCL) as part of Airworthiness Limitation List (AWL). That is FSL-07 which was added per AD 2008-13-09