Wings Walkways

This blog cover the installation of the wing walks in the port wing

Overview
Aluminium top hat sections are installed at the port wing root allowing the pilot and co-pilot to enter and exit the aircraft.

Installation
The plans for my model show four top hats on either side of the main spar and it was decided to begin at the wheel well.

The factory top hats were trimmed to overlap the flanges of the ribs. This creates a 0.020'' [0.5 mm] gap so a spacer was folded from 0.5 mm commercial grade aluminium to prevent buckling of the skin when riveted.

First hole

With the hat fitted it was positioned into the well and the first hole marked using a felt tip pen by moving the flange across the pen - with the vertical position marked it was removed and the horizontal position marked along the flange. Finally a 1/8'' hole is drilled and the hat refitted with a cleco, leveled and then the other three [3] marked and drilled.


Note: A single piece was used for ease of alignment and the flared hole because I have the tools

Spacer - Packer

The other top hats were now positioned and drilled using the same method.

Wheel well port side with stiffeners
The plan called for four [4] but this builder was unable to fit the last one as it
would lay under the gear prevent full retraction.
This will have to be stiffened and will be revisited

Rivet line for top hats pitched at 60 mm using FL drilling jig [seen lower photo]
Holes were not pre-drilled and had to be done by the builder

The supports located along the front of the wing were done in the same way except the the first two from the spar down. To fit the top hats around the fuel sender and to allow removal  this builder could not acheive this without some additional work.

One stiffener had to have the flange cut and infilled around the access hole drilled in the blog on the fuel tanks.  An angle was folded and riveted to the inside web to allow the rivet line to follow around the opening.

No 2 stiffener modifications
Note line above to mark center to modifyed top hat
Lost the plot here and pitched the rivets at 30 mm should have 
put a note on the skin - this works

The first stiffener [closest to the spar] was trimmed to create a channel fitting the available  space and then drilled for a single row of rivets along its centre-line.

Comment
Overall just time with the mods beign the best idea I had on the day but not the best idea.  I have noted on the drawings that the stiffener arrangement has been refined for the new aerobatic wing.

The stiffeners will be riveted after the tank is installed allowing the spar bolts to be installed - next year.