Known building "Gotchas" for the Sling TSi

[gaking]

Fuselage

A few things to be aware of:

1. The lower part of rib 8 is completely missing from pages 5 and 6 in the KAI version 7.9. Don't forget to attach that, the bolts and rivets need to pass through the upper section into that assembly too.
2. The KAI (version 7.9) does not point out that rivets need to be installed for the tail tiedown hook bracket into rib 8 and the longeron angle bracket to rib 7 (4mm and 3.2mm rivets respectively). Don't forget those.
3. Fitting the rear rib assembly 1 to the lower fuselage skin is tricky. The outer longerons (601) are in the way when trying to place rib 7 onto the lower skin, so remove those prior to fitting the assembly. Secondly, rib 9 is a problem because it has to be manoeuvred over the end of longeron 8 and once it is place it makes riveting the tailhook rivets mentioned in #3 above difficult. If I was to do it again, I'd do one of the following: a) only fit rib 9 once the rest of the assembly is riveted to the lower skin and longeron 8; or b) leave CHL 004 off longeron 8, rivet the rest of the assembly in place and then fit CHL 004 and the longeron angle bracket afterwards.
4. The gussets which hold the top step reinforcing channel to the longeron are almost impossible to rivet to ribs 2 and 3 due to the angle of the structure, although rib 3 is a bit easier. Even using a close-quarter rivet tool doesn't really work. The KAI has you rivet from the rear towards the front on rib 2. My suggestion is to rivet the vertical sections first (ie gusset to rib) or to do the horizontal section and then rivet from the front of rib 2 towards the rear, which is much more accessible. Don't forget to ream the holes through the support channels first if you need to, I forgot which makes it extremely difficult to do for the holes adjacent to the ribs once it's in position.
5. I have the non-parachute option, but am fitting the cables to the canopy to give me the option for a chute in future. The parachute cable tray holes do not align with any of the holes in rib 3 and the luggage bulkhead. Per Sling technical, "The rib forward of the bulkhead skin will be used in conjunction with the skin placement to fine and match drill the holes in the bulkhead skin and rib. This is something we are aware of that doesn’t fit, but this is how it is delt with currently."
6. It will be far easier to install edge protection on the ribs and longerons (for wiring harnesses and avionics coax) before the skins are installed. It's taken me hours to do afterwards because the access is really tricky.

[potatocover]

Regarding the rudder tip assembly, according to the instructions on page E.4.4., it's recommended to countersink the first 9 (nine) holes on the composite rudder tip piece. However, to align with the 7 (seven) dimpled holes in the rudder tip skin, you should only countersink the corresponding 7 (seven) holes in the composite rudder tip piece. This ensures proper alignment and assembly of the components.