Co-Pilot Seat - Part 1

This blog cover the installation of the rear seat and mounting brackets.

Overview
The problem that required Installation of spreaders to the front seat was the same for the rear seat. 

The factory has now designed a new seats to address these issue's.

Installation
Two 50 x 50 x 6 mm pads were fabricated, lightened and alodined for the front rear seat attachments to lift the seat to the designers relative position to the front seat.  

Packers & studs

Both air-frame mounting brackets have 20 mm od mounting holes with factory supplied thick aluminium washers. This mounting method deals effectively with the seat mounting issues, two [2] 3 mm x 40 dia washer were fabricated for the rear attachments covering the M8 seat mounting inserts. 

All four holes in the seat were chased with a M8 tap and a trial fit undertaken.

One issue found from the trial fit was the loose packers, so they were fixed to the seat using 3M trim tape. 

Rear packer and factory retainer bolt & washer

Note: The washers located under the seat bushes to ensure they cannot be pulled through the mounting holes if concentric at assembly

The front mounting point was now fitted to the seat, aligned and the seat re-installed into the aircraft. 

After fitting the seat the position of the front mounting foot location was marked onto the floor plate. Using that marked position the bracket was re-positioned onto the floor and a scrap of 0.020'' aluminium used to transfer the rivet line was across the mounting bracket foot. With the bracket removed and using the first rivet outside the marked position, the next three rivet centers was marked onto the aluminium strip with a pen. Finally the lug was re-positioned and using the reference rivet the location of the next three [3] rivet center marked onto the bracket, then removed and then drilled 5/32''.

Setout strip

The three [3] rivets that aligned with the fixing points were now removed and the center rivet drill 5/32'' with the bracket re-installed using the center hole secured using a 4 mm cleco. 

Using a long series 5/32'' drill all four [4] outer holes were drilled then the mounting bracket was riveted using three [3] x 4 od x 8 mm pop rivets at each side.

Note: Picked up all the existing 1/8'' rivet holes using this technique

The seat was refitted and the practicality of bolts to secure the seat was now called into question, this resulted in four [4] x M8 stud begin installed and another trial fit undertaken. 

Note: The geometry of the front studs required keyhole slots to be filed at both front mounting points 

A final check fit proved that the studs with a M8 nut and spring washer were a good decision as it makes installation relatively simple.

Rear seat mount and attachment for crutch strap [alodined angle]

The crutch strap mounting was profiled from 50 x 50 x 1/8 6061-T6 aluminum angle and bolted to the rear seat mount with two [2] x AN3 bolts and nylock nuts. 

Comment
The studs are now installed in the front seats as they are maintenance friendly and overall a lots less work than the front seats.