So, call me foolish and impetuous, but as the Great British Summer finally arrived this weekend (though I’m told it’ll only last for a week), I didn’t spend much time on the project. But I did put in a couple of hours and finished off the second seat plinth from last time. And I also built the basic frame for the pedestal, which actually bears some explaining.
At the moment, the frame – which is at its most basic – looks like this:
Hopefully this looks suitably pedestal-like, although it’s by no means finished, and indeed it’ll look quite different when I’m done. But it was easy to cut the basic shapes accurately and that was what I needed to do first of all, to get something in place and start measuring against the seating position precisely.
The problem, basically, is this: with both seats and the pedestal in place, there will be no way of getting into the seats other than climbing over the top of the pedestal – not advised if you don’t want to break something – or winding back the seat back, clambering over it into the seat, and winding the back up again. You’ll recall that my original solution was to buy MPV seats that swivel through 180 degrees; but that the available width in the shell is such that I can’t make use of this feature.
In real aircraft, this problem is solved by having the seat pull back and then move left / right (depending on the side) on what are called j-rails (you probably get why). This creates a gap between seat and pedestal through which the legs can move, allowing you to slide into the seat and then return it to position by sliding forwards.
This approach almost certainly won’t work in my case, because the amount of room to the left available with the seat pulled as far back as the shell floor will allow is pretty small – 120mm at most – and because that would mean me creating some equivalent to a j-rail system, when I had intended to bold the seat plinths directly to the floor.
Having a ‘stub’ pedestal – that extends only a little distance from the dash, as in most light aircraft that have a pedestal arrangement – would give me the room between the seats to get in, but since I want to get weather radar / CDU, throttle quad, flaps and trim controls, and a radio stack into my pedestal, that would not be suitable either.
If you’ve seen the fantastic remake of Battlestar Galactica – and if you haven’t, you should, even if you’re not a ‘sci-fi’ person – then you may recall that they frequently use a space vehicle called a Raptor which has a two-person cockpit that is, well, pretty damn cramped. The pedestal in their cockpit only really has the TQ on it, but it still gets in the way and they came up with an elegant solution – the whole pedestal folds up from the main panel and out of the way to allow the pilots to sit down. This inspired me to try a similar solution.
Now, if you’ll study the picture above you’ll see that this structure is a little unwieldy to be folding up on hinges – and it could probably only go to about 60-70 degrees, given that there will be thrust levers sticking out above it. My plan is to hinge it about a third of the way back from the MIP, so that the rear two-thirds will fold up; most likely the fold will be just behind the TQ, though this is one of the reasons why I’m doing more precise measurements with the seat in place shortly. The profile of the pedestal will change, with the rear part being much less deep and a large chunk being removed to make a cut-out (for some reason, the only comparison I can think of is the rear end of the starship Enterprise, where a chunk of the secondary hull is scooped out in a distinctive way that I don’t know the proper name for). A handle on the back will make it easy to move, and I’m trying to find a gas strut of the right extension and lifting power to make it a semi-manual process.
I know of no real aircraft that uses this solution, and indeed most two-seater bizjets with a narrower cockpit than mine seem to rely on a combination of narrower seats and tighter clearances – smaller LearJets being a good example – but I have no option about the width of my seats without getting new ones or fabricating them, and I’m not about to do either. This, I feel, is a reasonable compromise.
Right now I plan to prototype this arrangement using this basic frame and some existing hinges; and if it proves to work as planned, then I will finish off the pedestal frame accordingly, and that will mark the end of the first phase of the shell built – the basic structure. After that it’s time to work on interior trim, panels, and detailing.
I’ve now officially gotten further than my last attempt at a shell, and in a much shorter time, so I’m pretty happy right now. But there’s lots to do before electronics start going in. First proper flight by Christmas is still my goal.
backbedroompilot.com 