Fuselage Order of Build

Updated: 5/24/2018

The following is my recommendation for the general order of build in relation to the fuselage (of the Sling 4.  Though much of this would be applicable to the Sling 2).  The following is based on the manual, but even more so, on my experience and what I've learned from other builders.  Some steps shown are somewhat detailed because of my experience.  For ALL the following please refer to the manual (your primary source of instructions!) for the details and any missing info (NOTE: I do not detail every step!).  And before doing the following, please make sure it makes sense to you!  If you see something here that doesn't make sense, please let me know!



  1. Rear fuselage structure (but not including any skins).  Careful on the channels that run along the bottom of the rear fuselage - my manual has the orientation of them wrong and it's painful to fix, so double check.
  2. Put edge grommet material where the side channels pass through the ribs.  This is much easier to do now for when you later pass through the wiring.
  3. Install magnetometer in rear fuselage
  4. Install static ports in rear fuselage skins (check with the factory for proper location)
  5. Side skins of rear fuselage (but NOT top skins!).  Note these unmentioned skins that go on the tail: http://www.mykitlog.com/users/display_log.php?user=pgc&project=2346&category=0&log=257568&row=2.  Also see his "Previous Log Entry and "Next Log Entry" from the one linked.
  6. Install rear bulkhead
  7. Center fuselage bottom structure (no side skins) including all bottom skins (don't forget soundproofing material on the inside of the bottom skins).  Don't forget to use the fuselage jigs that span the center fuselage.
  8. Rudder pedals (Install the nosewheel pushrod rose joints NOW - Don't ask why I know this is a good idea...).
  9. Firewall install
  10. The manual shows the sub-panel (the panel behind where the avionics panel will be) being riveted in place - I do not recommend doing that until much later as you'll want to be able to take it out and add brackets, support braces, etc. for the remote boxes you'll be installing later.  Just cleco it in place for now.
  11. Install servo brackets
  12. Put dimensionally correct spacers where the forward wing spars will be inserted so they stay properly spaced throughout the build process
  13. Grease all pushrod eyebolts by squirting Aeroshell 22 grease with these: Grease gun and Needle nose.  You lube it by squirting it in the small hole on the side of the eyebolt until it comes out of the bearing.  You can use that grease for everything in the plane (wheels, etc.).  Alternatively you can use LPS #2 as this seems easier to apply (I've seen RV builders use that or Triflow).
  14. If possible, when installing, orient the eyebolts with the grease hole up, so that it can be greased more easily in the future.
  15. Put in ALL pushrod and torque tube assemblies now (way easier before center fuselage side skins are on).  Do this carefully, so they turn very easily and there's no play (can't move back and forth or up and down).  Also make sure the locking rings are in place (but not riveted) before riveting down the torque tubes.  Once you're satisfied that the torque tubes and pushrods work well, then you can rivet down the locking rings.
  16. Install auto-pilot servos and attach to pushrods.
  17. Joysticks
  18. Center fuselage side channels & Firewall
  19. Connect center fuselage to rear fuselage
  20. Rudder cables from front to rear
  21. Put long elevator pushrod through to rear
  22. Nose wheel pushrod holes need to have the boots added (note that the leather parts go on the inside.  I mention this because I've seen a builder put them on the outside and that's not correct).
  23. Install the two M6 rivnuts for the regulator that will be installed on cockpit side of firewall.
  24. Soundproofing on inside of firewall
  25. Construct center console (but don't rivet into cockpit just yet).  I put my front headset jacks inside the center console, so I did that too.
  26. Build seats
  27. Make sure rear holes for parachute cables (in rear spar upright) are properly sized.
  28. Put in flap motor and pushrod
  29. Build throttle quadrant (you're not installing at this time).  Note this heads-up: http://www.mykitlog.com/users/display_log.php?user=pgc&project=2346&category=0&log=257502&row=4
  30. Install ELT
  31. Install backing plates (and necessary holes) for your bottom COM and ADS-B/transponder antennas
  32. Run ALL wiring and static/pitot pressure tubing now.  WAY easier now than if you've got more skins on...  Here's an example list from my build:
    • COM1  
    • COM2  
    • VOR  
    • Tail lights  
    • Transponder/ADS-B to panel
    • ELT to panel 
    • Stick to panel: AP Disconnect, PTT (Push To Talk), Pitch Trim   
    • Flap motor to panel   
    • Pitch trim to pitch servo   
    • Pitch servo to panel   
    • Roll servo to panel   
    • Magnetometer to panel   
    • Rear headset wires to panel   
    • Front headset wires to panel  
    • Static line to panel  
    • Pitot (2 lines) to panel
  33. Install luggage floor.  If you plan to soundproof the underside of the luggage floor (I recommend it) do it now before installing.  Also, if you plan to add tie-down ring, it's best to that now too.
  34. Install luggage door
  35. Assemble and install parachute box (I held off on riveting it to any luggage compartment surfaces until I put the top skins on).
  36. Grease elevator pushrod in rear fuselage
  37. Install rear top skins including top COM assembly (finally!).  Make sure all wiring through the rear fuselage is well protected from any rubbing that could damage it.
  38. Install rear seat belts
  39. Install forward seat belt buckles through the center console.
  40. Rivet center console in place.
  41. Rivet inside front seat rails in place (do not rivet outside seat rails until much later when the wings are already attached!).
  42. Install nose wheel pushrods through firewall and attach to rudder pedal assembly.
  43. I've seen some builders install the front interior side skins before the outside side skins (wish I did because they're a bit tricky to install), so you may consider doing that.  Add the interior skin soundproofing before putting on the outside skins and you'll also need to add the soundproofing to the outside skins before installing (at least where it overlaps with the interior skin that's already installed).  Yes, that's two layers of soundproofing which some at TAF have recommended for a quieter and warmer cockpit.
  44. Install center fuselage side skins (finally!).  Do Not rivet the sub-panel in place yet (this is the rib behind the panel that will be used to mount the remote avionics).
  45. Front seat belt assembly.
  46. Soundproofing of center fuselage side skins.
  47. Take sub-panel out of plane and attach all brackets that will hold your remote avionics boxes to the sub-panel (the rib/panel behind your avionics panel).  Put back into the plane and rivet into place.  Note that the factory puts the 914's TCU on the engine side of the firewall, but this is specifically prohibited in the Rotax install manual.  I will install it and the waste gate servo on the left side of the cabin-side of the firewall near the large hole which I'll use to pass through the wiring to the engine.
  48. Nose gear assembly
  49. Install nose gear assembly into engine mount (easier since it's not attached to the firewall yet).
  50. Install rivnuts for heater box and any other rivnuts/holes drilled that can be done on the firewall.
  51. Clean firewall to be able to take fire-retardant primer (your choice if you want to use the material I'm using).
  52. Paint firewall with fire retardant primer.
  53. Rivet what you can to firewall that won’t interfere with the heat shield install, like the brake reservoir bracket and over flow bottle brackets
  54. Install the heat shield and rivet (or screw) remaining components to firewall.
  55. Install the heater box
  56. Main gear onto fuselage.  Torque the gear bolts BEFORE putting on the gear channel cover.  See: https://jpavlick.wordpress.com/2017/08/14/bottom-fuselage-rivets-filled/
  57. Attach engine mount to fuselage (only bottom bolts, top bolts are done after canopy is installed)
  58. Canopy (10mm 3.2mm rivers are used, not the typical 8mm long).  Add rivet holes.  See: https://jpavlick.wordpress.com/2018/03/12/canopy-install-part-1/https://jpavlick.wordpress.com/2018/03/13/canopy-install-part-2/,  https://jpavlick.wordpress.com/2018/03/14/canopy-install-part-3/ and
    https://jpavlick.wordpress.com/2018/03/20/more-canopy-stuff/.  Don't buy the Sika adhesive-related materials (there are several) until just before you're going to install the canopy as they have a short shelf life.
  59. Attach top engine mount bolts
  60. Best to install the rivnuts you'll use to mount the TCU and waste gate servo on the cabin-side of the firewall now before putting on the front top skin.
  61. Attach rear parachute cables.
  62. Finish install of seat belt reels.  Make sure it's oriented correctly!
  63. Rear interior skins, including soundproofing.  See: https://jpavlick.wordpress.com/2018/02/19/interior-skins-part-ii/
  64. Install ELT antenna bracket and antenna
  65. Carpeting in luggage area (soundproofing first)
  66. Carpeting in rear seat area
  67. Carpeting in front seat area
  68. Finish as much firewall work as possible before mounting engine: heater box and connecting heater box cable, brake lines, fuel pumps, turbo server mounting, TCU mounting, oil canister install, ambient pressure sensor mounting, over flow bottle install, etc.
  69. Install and rivet front top skin (pg. E14).  Sikaflex before installing (tape skin surfaces to keep clean)
  70. Dash
  71. Panel install
  72. Front screen
  73. Install engine
  74. Fit cowling
  75. Run electrical to sensors
  76. Run electrical to alternator, battery, battery contractor, master relay, etc
  77. Install water hoses
  78. Install engine fuel lines
  79. Install oil lines
  80. Outer seat rails not installed until wings are installed!