The following suite of pictures are intended to assist installers who are installing the Sportsman STOL modification on their Cessna aircraft. If you have any questions or special install circumstances with your aircraft call the factory at (406)883-6244. Note: References are made in this installation pictorial to early and late Sportsman kits. Any reference to an Early kit means any aircraft produced without a Cessna camber cuff leading edge, models included: All 150's, 175's, & 207's; pre-'72 182's & 206's; and pre-'73 172's, 180's, & 185's. A Late kit includes all models with the Cessna Camber cuff leading edge, models included: '72 & on: 182's & 206's; '73 & on:172's, 180's, & 185's.
Step #1: Aircraft Preparation: Prepare the aircraft for installation by removing the wing root fairings, inspection panels near the leading edge, landing light lense and retainer(when applicable), strut cuffs(when applicable), stall horn/switch, wingtips, and any other miscellaneous items around the leading edge. Clean the leading edge to make sure it is free of any oils or waxes.
Step #2: Nose Filler Block Placement and Installation: As shown on installation drawing SPI-400, sheet 1 of 4, place the nose filler block along the span of the wing directly on top of the existing Cessna factory nose rib. Consult the drawing to insure the placement of the correct block at the correct wing station for your applicable model of aircraft. With the nose filler blocks taped into position use your fabricated templates to verify the position of the nose filler blocks.
Step #2a: Inboard Wing Root Nose Filler Block Positioning: On most models of aircraft with the inboard cabin air vent the nose filler block closest to the wing root will have to encroach on the cabin air vent as shown in order for the inboard 520 skin to partially overlap the nose filler block. If this is the case you want to place the block so the outboard face is flush with the inboard circle of the cabin air vent as shown in the picture below. Verify the positioning of the nose filler block by placing the inboard 522 skin into position, i.e. outboard 522 seam lines up with the Cessna skin seam at wing station 100, and check that it partially overlaps the inboard nose filler block.
Step #2aa: Verifying Inboard Nose Filler Blocks Positioning (Wing Root to Wing Station 100): After verifying the position of the nose filler blocks with the templates use a straight edge to check symmetry from the furthest inboard block to the nose filler block at wing station 100. You are looking for all blocks to be level with the straight edge.
Step #2b: Verifying Outboard Nose Filler Block Location (Wing Station 118 to Wing Station 190) for Early kit aircraft(Includes all 150's, 175's, & 207's; pre-'72 182's & 206's; and pre-'73 172's, 180's, & 185's): After verifying the position of the nose filler blocks with the templates use a straight edge to check symmetry from wing station 118 to wing station 190. Note: The #30 Nose filler block at wing station 207 will not line-up with the other blocks. Its placement will be higher than the others.
Step #2c: Verifying Outboard Nose Filler Block Location (Wing Station 118 to Wing Station 207) for Late kit aircraft('72 & on: 182's & 206's; '73 & on:172's, 180's, & 185's): After verifying the position of the nose filler blocks with the templates use a straight edge to check symmetry from wing station 118 to wing station 207.
Step #2c: Adhere Nose Filler Blocks: With the nose filler blocks taped and position verified proceed to glue into place using the supplied Silastic RTV adhesive.
Step #3: Aileron Gap Seal Installation: Installation drawings SPI-400, View A-A, sheet 2 of 4. While our blocks are drying in place proceed to install the aileron gap seals by drilling out the #3 rivets ahead of the aileron.
Step #3a: After drilling out the rivets remove the original stiffener material between the top and bottom skins and cut the aileron gap seal stock to length and insert into position.
Step #3b: With the trimmed aileron gap seals in position place the aileron in the full up position and set the gap to .020 between aileron and aileron gap seal and drill and cleco into place.
Step #3c: Remove aileron gap seal, debur, paint, reinstall, and rivet the aileron gap seals into position. Note: We commonly remove the aileron to rivet the aileron gap seal into position.
Step #4: Fitting Plenum Block P/N 529 & Stall Switch Doubler P/N 528: Installation drawings SPI-400, View F-F & View E-E, sheet 3 of 4. With the nose filler blocks firmly glued into position trim and fit the plenum block P/N 529 into position. Note the plenum block positioning with regards to the "Lower Cabin Air Vent" mark and the top is flush with the bottom of the OEM cabin air vent.
Step #4a: Seal the plenum block P/N 529 into position.
Step #4b: Position and install the stall switch doubler P/N 528. Note: The positioning shown by the black Sharpie outline in the picture below represents the opening for an electric switch installation. For pneumatic horn installations you want to shift the Sharpie outline so it lines up with the green line depicted in the photo, i.e. were the bottom is flush with the two lower mounting screw locations vs. flush with the bottom of the horn opening.
Step #4c: Drill and cleco the stall switch doubler P/N 528 into position. Debur and rivet into position.
Step #5: Installing P/N 522 Leading Edge Skins(Early Kit): Place the outboard 522 skin onto the aircraft with the inboard edge flush with the inboard face of the #31 nose filler block and tape into position.
Step #5a: Mark and trim the outboard excess of the skin so it is flush with the outboard rib of the wing.
Step #5b: With the 522 skin trimmed once again and place skin onto the aircraft and tape into position so we can begin fitting the next skin.
Step #6: Installing P/N 521/A521 Leading Edge Skins(Early & Late Kits): Place the 521 skin (Early kit) or A521 skin (Late skin) into position by overlapping the 522 skin and lining up the inboard edge of the skin so it is flush with the inboard face of the nose filler block at wing station 100 and tape into position.
Step #6a: Trim the skin to length. For an Early kit the skin will be trimmed to wing station 190 while for a Late kit the skin will be trimmed flush with the rib on the end of the wing, i.e. wing station 207. For an Early kit make sure to trim the skin so it is flush with the existing skin seam at wing station 190 as shown in the photo below. Once trimmed to length
Step #6b: Trimming For Landing Light Assembly(Early Kit): View H-H, sheet 4 of 4. Once the 521 skin is cut to length place the skin into position, mark, and cut the LH skin for the landing light assembly. Note: Cut line should be aligned with the edge of the Cessna doubler P/N 0722100-1.
Step #7: Installing Inboard Fiberglass Transition Fairing P/N 524(Early Kit), A524(Late Kit): In preparation for installing the inboard 520 skin place the inboard 524 transition fairing onto the aircraft by lining up the inboard edge with the inboard edge of the wing. Tape the fairing into position.
Step #8: Installing Inboard 520 skin: Place the inboard 520 skin into position by overlapping both the 524 fairing and the 521 skin and aligning the outboard 520 skin edge with the skin seam at wing station 100. Note: On the L/H wing you may have to notch the 520 skin so it clears the pitot tube, View D-D, sheet 2 of 4, installation drawings.
Step #9: Locate Cabin Air Vent Locations, Stall Switch/Horn Location, and Inspection Doubler Locations: With all the skins in position use an inspection panel and Sharpie to scribe the location of all inspection panels. In addition locate and mark the span wise location for the cabin air vents and stall switch/horn. You will likely have to remove and reinstall the inboard 520 skins to complete locating the cabin air vents and stall switch/horn. IMPORTANT: If you had to encroach on the inboard cabin air vent with the nose filler block you will need to shift the cabin air vent opening outboard to insure the inboard edge of the new cabin air vent hole is outboard of the outboard face of the nose filler block.
Picture showing inboard Cabin Air Vent shifted outboard.
Step #10: Skin Preparation for Aircraft Installation: With all skins trimmed to length and all inspection panel locations marked it is time to begin drilling pilot holes for attaching the skins to the airframes. Use a #40 drill bit. Make sure to use the proper rivet pitch of 2" and edge distance of 5/16", sheet 1 of installation drawings. IMPORTANT NOTE: We do NOT drill any pilot holes next to inspection panels, at overlap joints, near pitot tubes, or within 4" of overlap seams. We come back and drill those holes once the skins are initially cleco'd into position and all inspection doublers are installed,etc. This insures we do not violate rivet edge distances by drilling to closely to these components prior to their final installation.
Step #10a: Roll Lap Joint Skin Edge: On the 521 skin, Early kit only, roll the outer edge as shown in View C-C, sheet 2 of 4. For the 520 skin roll both the inboard and outboard edges. This makes for a nice tight seam between the two skins.
Step #11: Installing Skins on Aircraft: With the pilot holes drilled begin fitting the skins to the aircraft. Start outboard and make your way inboard. When fitting the 520 skin make sure the fiberglass inboard fairing is in position.
Step #11a: Trim Uneven Skins At Lap Joints: At the overlap joints it is not uncommon for one skin to be longer than the other skin. Mark and trim the longer skin so the skins have a continuous seam spanwise.
Step #12: Install Inspection Doublers, Cabin Air Vent, and Stall Switch/Horn holes: Inspection Doublers: With the skins cleco'd into location once again scribe the outline of the inspection covers to mark the cut-line for installing the inspection doublers, P/N's 530, view B-B, sheet 2 of 4, installation drawings.