One template per seat rail required. Models 150-152 do not require templates as the screw holes are predrilled. Model 177 Cardinal seat rails require one (1) SRTEM3 templates per rail. Seat rail series MC0511240, MC0511243, MC0514209 and MC2414002 use SRTEM2. All other rail series use SRTEM1.
McFarlane Aviation discovered while installing and developing our replacement seat rails that the seat rail attachment hole pattern was not consistent from aircraft to aircraft. Even small inconsistencies in the hole locations made installation of new seat rails very difficult. For this reason, McFarlane seat rails do not have attachment holes. This allows the installer to match the holes in his specific aircraft floor. Templates are used to achieve a precise fit of the new seat rail.
How to use McFarlane Templates:
Clamp the template to your old seat rail.
Drill holes through the old seat rail into the template.
Clamp the template to the new seat rail and drill several holes through the template and new seat rail.
Set the new seat rail in position in the aircraft and check for proper seat rail alignment. The seat rails must be properly aligned and parallel with each other.
Clamp the templates again to the new seat rail and make any required alignment adjustments discovered during the aircraft test installation.
Drill all the required holes through the template and the new seat rail.
The aircraft floor is subject to corrosion from moisture under the seat rails. Be sure to remove and treat any corrosion before installing the new seat rails.