Canopy - Latch

This blog cover the installation of the canopy latches.

Overview

The original opening in the side panel for the pilots latch actuator was totally inadequate and a larger opening was required as shown below with a cover to be fabricated later. 

Opening showing brass rubbing plate with the polished area 
showing mating faces with the handle flange

Latch Location
To determine the front latch pins relationship to the hook two AN4 area washers and washer spacers were fitted to the threaded rod then a series of lock nuts fitted allowing the assembly to be adjusted until the hook landed on the center of the assembly.

Verner's were then used to determine all dimensions with the rear pin location fixed no measurement was required.

Front Latch Installation
The original aluminium latch had to be move out into the cockpit about 10 mm supported only on the M6 threaded shaft. Rather than add washers a single piece brass latch was machined with a 1.5 mm fiber washer placing it about 0.005'' from the brass rubbing plate [shown above]. 

Once the correct position was established the brass latch was fixed to the shaft using high strength Loctite.

Note: The intent is to transfer uplift load via the stringer face and the M6 shaft. 

Front Latch Pin

The hook was installed after begin located from the inside of the cockpit using the latch as a reference. Its location is critical as it has to allow the hook to engage with the latch pull fully back and then allow the latch to engage the hook when closed. Initially fixed with four [4] clecos in a triangular pattern to allow the operation to be checked

Rear Latch Installation
The rear hook required a 1.5 mm spacer behind it to clear the latch flange and was located as described for the front latch.

Rear Latch Pin

Note: The M6 threaded rod at the rear was not long enough and the brass latch was used to remedy this issue - make sure there is about 30 mm projection from the face of the stringer then trim as required and the factory catch will fit correctly.

Latch
Operation was checked from the outside and adjusted until both hooks engaged smoothly by using a fine file to adjust the length of the nose of the hook along with the entry ramp only with relation to the latch pin. Only the lightest of dressing is required if the geometry is set up correctly at he start

Both hooks were fixed using tri-fold 4.8 mm pop rivets in a belief that these will resist side loads in a superior manner compared to pop rivets in the fiberglass side.

Note: The smallest tri-fold available is 4.8 mm

Handles
The handles were removed from the original latches with a razor saw and then machined square for re-installation onto the brass latches. Holes were drilled at the ends to allow a Tommy bar to be used to lock up the assembly.

All handles will be coated with liquid red plasti-dip with each component dipped twice [min] to achieve suitable coating. The finished coating creates a tough soft grip but once opened the contents has a limited life so it will be done with a lot of other items at a later date

Comment
Worked as designed with adjustments - see gas strut install re alignment issues.

Why the front latch had to move so far is unknown.