Friday, November 30, 2007

Horz stab skinning

Build hours: 315

The UCA tail is now hanging from the rafters waiting for the lexan inspection plates to be installed before final closure. The UCB tail is installed and drilled awaiting cleanup, and inspection holes. The UCB tail has taken half the time and a fourth of the struggle to complete since we have the experience from UCA! A few steps in the manual could have made it all a lot more painless. I do not recommend building the tail on the plane but the alternatives suck too.
The clamps pictured below are cheap and easy and greatly simplify the skin installation. Some light spring clamps on the trailing edge will hold until the skin is positioned.

Here are five items to watch for when constructing the tail -
spar level
correct incidence
inboard edge fit
outboard edge square
spar pucker
Check each item and often during the fitting.

Plan note:
The basic steps (which the kit guide doesn't mention, (falls under - should have prior building experience)) are:

1) Mark all flange centerlines before assembling the spars and ribs on the fuselage. Extend the forward spar centerline onto the fuselage and onto the outside of the outboard rib.
2) Install the rough cut skin as pictured and clamp. (Check the 5 items).
3) Use a guide to create the fuselage trim line

4) Remove the skin and trim the fuselage line.

5) Reinstall the skin (Check the 5 items). Mark the ends of the forward spar on the skin. Mark the trailing edge trim line. Mark the outboard rib trim line.

6) Remove the skin. Trim the trailing edge and outboard edge. Mark the spar rivet lines top and bottom, front and rear. Mark the rivet pattern on the inboard rib. Measure and record the distance from the inboard rib rivet to the fuselage and record it on the fuselage.

7) Reinstall the skin (Check the 5 items) . Mark the inboard rib rivet pattern using the recorded distances.

8) Drill and cleco several inboard rib holes top and bottom (Check the 5 items).

9) Push or pull the forward spar to align the flange line and procede to drill every 3rd or 4th hole to the tip (Check the 5 items).

10) Mark and drill the top trailing edge (Check the 5 items) and bottom trailing edge every 3rd or 4th hole. Drill the outboard rib top and bottom and then complete all drilling.

11) Go to bed - you've been at this for a long time!

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