Installation Instructions for Sportsman Modification
The following sequence of installation instructions for the "Sportsman" modification to the Cessna wing is for your convenience and time savings. The primary reference documents are the installation blueprints and Process Specification 732. Read these carefully before you start the job.
1. Remove all inspection panels, wing root fairings, landing light lens assembly, and wing tips.
2. Early Kit Installation, Cut-out the contour templates using the templates provided from the masonite lid utilized for the shipping crate.
Placement of Transition Blocks
3. Clean the wing per Process Specification 732.
4. Fit and position nose blocks using top surface contour templates (contour templates are only available for early model kits, pre-1973 model Cessna’s, all late models do not require the use of the contour template). Use masking tape over the blocks to hold them in place. Hint: The blocks are intended to be placed directly in front of the Cessna nose rib.
Tip: For placing the inboard block fit the inboard fiberglass fairing flush with the inboard skin of the wing. Place the block so the inboard fiberglass fairing overlaps the entire block. Mark position and adhere into place.
Note: If this encroaches on the cabin air inlet you will need to position the block further inboard.
5. Mark the outline of the blocks and remove the blocks from the wing. Scuff the marked locations for the blocks on the leading edge to provide a rough surface for the adhesion of the silastic RTV.
6. Place the blocks back onto the leading edge once again using tape to hold them tight against the wing and apply the RTV adhesive. Allow the blocks to set for 24 hours. Hint: Utilize the 520, 521, and 522 skins to check the fit/positioning of the foam blocks.
7. At the cabin air inlet locations in the wing leading edge install the spanwise plenum blocks, P/N 529 or A529, between nose blocks with RTV adhesive. Seal the inside on the spanwise blocks and sides of nose blocks with silastic to weather proof.
Installation of Aileron Gap Seals
8. While the nose blocks are drying the aileron gap seals can be installed.
9. Remove the existing AD3-4 rivets at wing trailing edge between aileron hinges. Cut to fit the respective aileron gap seal material and fit into the back seam of the wing, set gap/spacing, drill and cleco into position. Spacing is set with the aileron in the up position.
10. Remove the aileron and squeeze the new rivets in place.
Installation of Wing Skins
11. Trim the 522(applicable to early kit only) and the 521/A521 skins to length. To do so line up the inboard edge of the skins so it is flush with the inboard of the respective transition block, block 31 for the 522 skin, and block 36(early kit)/A36(late kit) for the 521(early kit)/A521(late kit) skin.
12. Before installing skins, the air inlets and stall warning aperture must be marked on the wing to be able to transfer markings to the new skins. Mark a line from the center of the cabin air inlet and stall switch far enough aft to clear the top edge of the new skins.
Note: Both a pneumatic and electronic stall horn templates are provided. Use the appropriate stall horn template for your applicable application.
13. Tape the 524 inboard fiberglass fairing in place and begin installing the skins starting with the outboard first. (Refer to photo's above)
14. (Applicable to early kits only) Have the 522 skin overlap the 31 transition block and tape into place. Mark the excess skin material extending past the outboard of the wing and trim. Secure the skin in place utilizing masking tape. (This step only applies to the installation of the early kit)
15. Fit the 521 skin next and pull down to a tight joint at Station 190 (Station 207 for late model kit, and Station 174 for Cessna 150/152). Make sure the 521 skin overlaps the 36 block at Station 100 (Station 84 for Cessna 150/152). Hold the skin in place utilizing masking tape and mark left hand skin for landing light cut-out. Once again trim excess and secure the skin in place utilizing masking tape. For aircraft with a landing light lense mark the 521 skin so it is flush with the Cessna recessed landing light doubler assembly, Cessna P/N 0722100-1. It is important that the 521 skin is trimmed to the edge that defines the narrowest opening otherwise the landing light supports, 514 & 515 will be to narrow.
16. Fit the 520 skins. Mark and cut out for heated type pitot on left skin (if used). Insure the proper 5/8" overlap at both the inboard fiberglass fairing and at Sta 100. Transpose the air inlet and stall warning marks from step 11 to the new leading edge skin. Utilize supplied templates for the air inlet and stall warning (use appropriate pneumatic or electric stall horn template) and drill out the new holes in the new leading edge skin. Secure skin in place using masking tape and mark the edge locations of the inspection panels.
16.5. On a few models of airplanes AN470 raised head rivets were used by Cessna to rivet the nose ribs onto the wing. Anywhere the Sportsman skins come into contact with a raised head rivet the original raised head rivet must be removed and replaced with a countersunk rivet.
17. Run a strip of masking tape along the edges of all skins top and bottom. Mark a line 5/16” in along all edges, then lay out the 2” rivet pitch on top and bottom edges. Make sure to account for the location of the inspection panel edges as marked in step 16 when drilling the holes on the bottom edge. DO NOT DRILL any holes at any of the edges or overlaps for both top and bottom edges and DO NOT DRILL any holes next to the inspection panel edge locations that were marked in step 16. Drill the edges of the skin with no. 40 drill bit.
18. Tape the 524 inboard fiberglass fairing into position as the 520 skin will be placed over the top of it and begin securing the skins to the aircraft. Begin with the furthest outboard skin 522(early kit) or A521(late kit), position onto the airplane and once the fit is verified begin to drill out the holes with a #30 drill bit and cleco to the aircraft. Repeat operation for securing the remaining inboard skins remembering to maintain your proper overlaps and verifying fit prior to drilling.
19. Once all skins are secured in place the inspection panels need to be marked and cut out of the new leading edge skins. First install all access covers with two P.K. screws to original doubler plate so the access cover lies over the new leading edge skin. Scribe around the panels to mark the area to cut-out. Now remove the leading edge skins and perform the final trimming on the new skins to account for the inspection panels. Install the new doublers provided with the kit with the AD3-3 rivets also supplied. Make sure to position doubler as to line up the screw holes.
20. Now that all skins are trimmed and ready for installation complete drilling out the rivet locations on the bottom of the wing. Once again utilizing a 5/16" spacing off of the edge of the skin with a pitch of every 2".
21. Install the stall warning doubler plate over original leading edge and mark the the lines to cut-out the center of the original location. Proceed to cut-out the material and then install the stall warning doubler per the drawings.
22. Place the skins into position on the wing and begin to drill all holes and secure into place with Cleco’s at a spacing of every other hole. Once secure in place go back and countersink all holes with a 120º countersink bit.
23. Once complete with countersinking remove skins and clean surface. Now you are ready for final installation of skins however prior to final installation of skins, attach the stall switch to the 520 skin prior to final installation (installation was completed in step #16). Coat the top rivet row with RTV adhesive and also coat around each transition block. DO NOT place any adhesive on the bottom row of rivets. Once skins are secured in place begin to rivet into place.
Landing Light Lens Installation
24. Once skins are secured install the landing light lens assembly. Fit the fiberglass 514 landing light lens supports into the new leading edge assembly and rivet into position. Note: The locations indicated with permanent marker are the locations for new tinnermans to secure the new landing light retainer.
25. Remove the bottom and top lens supports from the original landing light lens(applicable to early models). Fit the new landing light lens and retainer into the wing and identify the location for the original lens supports along with screw holes for the new retainer. Once everything is in position drill holes and rivet the original lens supports onto the new retainer as to keep the landing light lens secure. Screw new landing light lens assembly into place.
24. Install wing tip fairings as per instruction on appropriate installation drawings. Direct replacement of wingtips can be done by installing wingtips, part number SA-0523565-SPR,-SPL in accordance with appropriate manufacturers service manual. Continued airworthiness of wingtips should be in accordance with FAR 43 appendix D, checking for cracks, attach points and clearances from any moving parts.
25. Weight & Balance = 15 lbs @ 22"
26. Complete form 337
SPORTSMAN INSTALLATION PICTURES