It’s been a while…

So…. It’s been a while… Sorry…. It turns out I’m not so good at keeping a blog up-to-date but that doesn’t mean progress hasn’t been made!

Apart from the general tidying up of some of the frames, there was a magical moment when a temporary floor was fitted. I say magical because up until that point it was quite easy to misinterpret what was in front of you. Yes, I know it’s a plane but, while its upside down in the jig with frames and other structural elements missing, it’s easy to forget that. The addition of the temporary floor, along with the missing frames 5 and 5a in place, really started to give the structure some shape – a moment for feeling smug!

Why a temporary floor? Because it’s not known exactly what shape the plywood skin will take when fitted round the frame. A close estimation has been made which, if accurate when in place after the skin fitting, can be used as a template for the actual flooring.

Another big change that’s been made is the location of the undercarriage at the front of the plane. Originally placed between frames 3 and 4, it now lies between frames 4 and 5. Both new plates and blocks were made to fit frame 4 as the angle between 4 and 5 differed from the angle between 3 and 4. The new plates for frame 4 were originally made from Perspex to allow the fitting to be gauge. Once satisfied with the fitting they were then cut from metal.

We also had a visit from an inspector who reviewed the work that had been done so far to check it was of the required standard. He seemed satisfied with what had been completed so far and listened as Alex outlined further plans whilst making suggestions himself. He also mentioned we were to keep a log of the work that had been completed.

The original outer of the Bowden cable used to control the trim has been replaced, although fixing it to the side of the aircraft proved somewhat of a challenge. The original cable was loosely held into place with pins and wooden blocks. Removing the cable damaged some of the old fittings however, it had already been decided to replace these with a new design. The new design involved using a laser cutter to produce a U shaped fitting (shown below) that would slide over the cable and be glued in place of the airframe.

In theory, this worked very well, allowing the cable to slide through the fittings without flapping inside the aircraft. In practice, this also would have worked very well had it not been for difficultly in accessing further down the tail of the aircraft. Access at the front end came via where the skin had been removed aft of frame 7, allowing enough space to squeeze your upper body in and reach down the aircraft. Access at the tail end came via two access holes either side of the plane. Despite allowing someone with slim arms to reach inside, due to the size of the hole viewing, access was limited. Between myself and Alex we could reach a fair bit inside the aircraft except towards the centre between the access points. This proved a problem when trying to attach the fittings as we could not reach to clamp or staple them after gluing. This led to a rethink and an alternative solution whereby a carbon fibre tube was attached to the side of the aircraft with the help of the original structure. The Bowden cable could then be fed through, guided by the tube, allowing for easier access and future maintenance of the system.

The replacing of the Bowden cable emphasised the importance of adapting your approach when design issues occur and accepting that although an idea works in theory it may not always work in practice.

One of the next tasks will be to fit plywood skin to the underneath of the fuselage where it had previously been removed before turning the fuselage over. The aircraft can then be moved to its new home in the Stephenson building of the University before further work is carried out.

(Once again anything posted on this blog is my own view, not that of Teesside University or anyone else associated with the project.)

 

Introduction

When I first started my Aerospace Engineering degree at Teesside University a couple of years ago I read a blog about a project involving a small aircraft housed somewhere within the university called a Ganagobie. Being young and idealistic I swore to myself that I would make it my mission to find this Ganagobie and involve myself with it. After two years I completed this mission; the Ganagobie was found hiding in the Orion Building and my lecturer, Dr Alex Ellin, had kindly allowed me to become part of the project.

Now if you type Lobet Ganagobie into an internet search engine you will see a series of pictures similar to the one below, which shows the Ganagobie when it was first delivered to the university.

It’s missing the wings on this picture but on first impressions it looks like a plane.

Below is how it looked when I first saw it.

Now I’m no expert but even I can see this plane is in no condition to fly. For starters it’s upside down and in a jig, has no wings or engine and there appears to be a bit of a hole in the fuselage. I’m informed this is all for a valid reason – although suitable for a petite person to fly, someone of a larger height would struggle to fit in the aircraft. Therein lies the main challenge, to extend the fuselage 6 inches. Now if you were thinking you could just chop the front end off, bit of wood, bit of glue, cover and voilà, done, you would be slightly mistaken. There appears to be rules and regulations covering this sort of thing. The extension has to be done such a way that the aircraft will still be deemed fit to fly by the Light Aircraft Association (LAA), for the obvious reason that, if not, a fatal accident could occur.

That was the situation a couple of month ago. This is what the Ganagobie looks like today.

At first glance the appearance may have not changed much but significant progress has been made. The first tasks tackled were those of extending the longerons to accommodate the extra space required and rebuilding Frame 3. The longerons were extended using a scarf joint. Both the original longeron and the extension were cut at a shallow angle and then glued together. The scarf joints on both sides of the aircraft are further supported by longeron doublers, which themselves were completely removed and replaced. Frame 3 needed to be rebuilt as the original was damaged when removing the plywood skin.

With the longerons extended, the frames and bulkheads can be placed into position, ready to be secured when final locations are confirmed. A new frame, frame 5A, is to be placed between frames 5 and 6 (unsurprisingly) to compensate for the extension. The final position of this frame is unknown as the extension will cause the reconfiguration of other components and it may need to be rejigged to avoid interference.

Further tasks include creating a new torque control tube as the original is now 150mm too short. A temporary tube was fitted that ensured the correct placement of bulkhead 4 by allowing the tube to rotate freely. From the new torque control tube the positions of frame 5 and 5A can be finalised. A new cockpit floor and supports need to be formed, the position of the seat needs to be adjusted so that it gives a more comfortable, inclined seating position, new elevator control cables need to be fitted to cater for the extra fuselage length and the lower skin will need to be fitted. All this will hopefully be underway before the summer.

You might think ‘why bother?’ From a student point of view it is an excellent learning experience. Although some of the students on the Aerospace Engineering course have prior physical experience of aircraft, for those who don’t it allows them to gain this experience. It allows a student to apply the theory they have learnt in class by working on a live project, gaining an insight into different aspects such as CAD, project management, structural analysis, quality control, materials and manufacture (this list is by no means exhaustive). From any of these areas ‘mini-projects’ can be formed which can be used for final year individual projects and of course it can also look pretty good to a potential employer on a CV and become a great talking point at an interview.

I realise I have probably crammed quite a lot in to this first post so I intend to try and backtrack a bit with future posts to give a greater overview of what has been achieved so far, as well as updating with the progress we make beyond this point.

(I should just point out that anything posted on this blog is my own view, not that of Teesside University or anyone else associated with the project.)