Back to the beginning: Project Tiger Cub Story part 12

Some work in the cockpit

Following Ben’s visit I set to finishing the front section of the fuselage. The front end I’d left pinned together with old bolts and I had done no riveting until Ben had seen my newly fabricated front tubes. So I completed riveting up the new throttle quadrant so that the throttle support tube could be fitted. I offered it up to strike a problem, it didn’t fit. Humm, it had fitted before when back in the mists of time I had dismantled it. Then I got it, despite the trouble that I’d taken with labelling everything up I’d fitted the starboard upright to the port side and visa versa, Idiot. Ohh well, stupid but curable with care. By cunning use of the triangulation of the structure I was able to remove both main uprights replacing such bolts as held other tubes in place in the right order so that I could swap the offending tubes over while maintaining the structure. Those in place, the right place this time, the throttle support tube slid neatly into place. Then working my way methodically though the assembly I replaced the old bolts with new ones painted with Zinc Chromate and wound on the new nylocs. 

I really could now feel that I was starting on the fun bits and get started at installing the controls. First off, the rudder pedals, I fitted them to the brackets that I re-installed on the cockpit floor after crack testing. They moved smoothly on their pivot and the end float was exactly as specified in the build instructions,

 I was starting to get a good feeling about this. Next, install the front cockpit floor, no room for error here, as this is structural giving triangulation to the front of the cockpit. I slid it into position and clamped it up only to find that I had pinched the monel rivets that I had bought hold it into place for another job. A bit of a pain, but not a disaster nothing that a call to LAS wouldn’t sort out. So clamping it into place I moved on to the rudder pulley in the rear of the cockpit section. No sign of wear to the pulley bearings so after a bit of a clean up the pulleys spun as merrily as new. Fitted with nice new bolts I slotted them into place and another little job was sorted. The next thing to re-fit was part of one of Jim Romains mods. It was just as well that I had taken pictures of the bits before dismantling. For this one Jim had changed the non-differential cable driven aileron circuit for a rod controlled system that provided some differential to the control.

For this one Jim had changed the non-differential cable driven aileron circuit for a rod controlled system that provided some differential to the control. To achieve this he had fitted a sleeve with two offset arms around the outer tube control column. Attached to these control rods ran to bell cranks that were mounted on an additional tube fitted athwartships.

These provided the differential and another rod each side ran to the bell cranks which are detachable to allow wing folding, these fit to the ends of the aileron control tubes. As I am missing one of the control rods I’ll have to get one made to the original spec. As I have been cleared by Ben to get this done at an aviation workshop to only real problem will be the cost. As the second tubes will be easy to fit later as long as the cockpit sides are left open I can still press on.

The hiccup with the rivets for the floor proves to be to my advantage as Ben is unhappy with the use of monel rivets in that position. He had gone away a worked out the rivet loading, because it was right behind the front bulkhead it was subject to considerable side force from propeller torque and a good deal of vibration. According to the “Big White Book” the FAA standards for inspection and repair, pop rivets should not be used in places where they are subject to vibration unless the rivet walls, without the central mandrill, are up to taking the load. It seems that monel rivets are not, all was not lost though as Ben found some stainless rivets that met all the requirements of the “Big White Book” and the bit in the CAAs own ‘Section S’ that covers side loads on engines.

Back to the beginning: Project Tiger Cub Story part 11b

– and a surprise visitation

Then out of the blue a phone call from Ben in the BMAA tech office, he would like to come to see me and discuss the project so we agree a date. I hang up, well press the red button on my mobile but the term “hang up” conjures the wonderful vision of the old Victorian phones. Anyway I digress, but the idea of carting one of those around in my pocket amuses me.  Then I begin to wonder what I’ve done wrong, am I going to be manacled and hauled to Gatwick to explain myself? I can think of nothing, so with a feeling of unaccustomed virtue I begin to look forward to the visit.

On the appointed morning I answer the summons of the bell and open the door to find Ben complete with briefcase and camera bag. Over coffee we go though the mod status in fair detail, Ben has written them up in a little table to simplify the mass of Service Bulletins, some from MBA (Micro Biplane Aviation), some from TCD (Tiger Cub Developments) and of course the Romain modifications themselves. As I’d already noticed some later SBs supersede earlier ones and some Romain ones replace or supersede others. It is a bit of a tangled web, but with all the documentation spread over the dining table we unravel it until it makes sense and we agree the final mod status for GMJSP.

Then it is time to view the beast in its lair (the workshop). As it is the first Cub that Ben has seen he is surprised at how small it is, just as I was when I first saw one back in the early eighties. After a good look over to see just how it is put together he focuses in on the replacement parts that I have made and the parts that I propose to have made.

Firstly the made components, the replacement throttle quadrant that I have made to the drawings in the SB that requires the change from original and then the new “A” tubes. These are the ones described in episode 7 and my new ones are made from 6061 T6 alloy. Ben does a quick “back of fag packet” sketch and calculation and seems happy with what I’ve done but he will do a full stress analysis back at the office. I describe my workshop procedures, separation and labelling of parts as well as the checks carried out.

 We then retire back to the dining room table and some more coffee to discuss the parts that I intend to have made, the missing control rod and a new set of rigging wires. He seems happy that I intend to have both of these professionally made within the aviation industry and we go though the Aircraft Spruce Catalogue to make sure that the rod end bearings that I need are still available. Firing up the computer we sort though my workbook to locate the sources of components to be used in the final build. After making some notes we head back to the lair, or should that be den I really don’t know what is appropriate for Tigers, for Ben to take some photos.

Finally Ben tells me that he is generally happy with my repair scheme and will sort out an appropriate inspection regime and send it though to me, Result!

After another coffee we head to the farm to view the Cub that is in one piece KT.

Another coffee later Ben struggles into the cockpit and like everybody else is amazed just how much room there is in there, when you are in, a veritable Tardis of an aeroplane. As he remarked it is all very eighties.

So all in all an extremely successful day and I await the documentation plopping though my letter box. I enjoyed meeting Ben and it certainly gave the lie to all the rubbish that has been spouted about the denizens of the tech office. Ben is an enthusiastic microlighter who flies both flexies and three axis aircraft. He has both a Quik and is rebuilding an MW5 and his enthusiasm for microlighting glows around him like an aura.

Of course after such a good day I could be a little biased.

Back to the beginning: Project Tiger Cub Story part 11a

Progress at last, fitting the fuel tank

With the tray made and ready to fit I glued in the runners for the construction to sit on I was now ready for the next stage. Cutting strips of thin birch ply I fixed those with epoxy resin to the leading edges of the foam that form the front of the rear fuselage section. This was then re-enforced with glass fibre tape all as detailed in the tank lowering mod.

As soon as I had fitted an outlet pipe to the drip tray it was all ready to start to come together.

Sliding the tank into place and fixing it with the ever ready epoxy resin I started to make the polythene curtains to line the sides and rear of the foam. This was a weird shape but the third one fitted and epoxy and tape soon had it fitted in place.

The next thing was to get the tank fitted to the front fuselage section and the first piece of that is the rail that holds the shoulder straps of the seat harness. I have several sets of harness so I check them all over, going over the stitching carefully. I am happy that the best set of all is the one that came from SP. Being stored all those years seems to have helped and the webbing and stitches are in good shape with a small amount of rust on the face of the buckle showing as the only blemish.

The top support for the tank bolts to the shoulder harness rail with the webbing that holds the tank between the two alloy sections. This webbing is also in very good shape and I have no hesitation in fitting it and the nicely cleaned tank is hauled into place. With the lower support fitted we are almost ready to unite the fuselage sections. There is a short delay as I have borrowed a “T” piece intended for the fuel drain to use on the other little project, that of tidying up an AX3 for Saxon Microlights and like a clot I’ve not replaced it straight away.

In the meantime I revert to the preparation of the paperwork and spend some time copying the Tiger Cub maintenance manual and the Pilot and operators handbook to disc where they join the Build Manual that I had already sorted. I’ll send copies of this to the Tech office with the Service Bulletins; I’m amazed that they don’t already have this stuff. I cannot see how they have supported the type all these years without, as they seem to have almost no information at all and Tiger Cubs have been around for better than 25 years.

In the midst of this we visited the SPLASH aviation show at the NEC, I must be strange because I enjoyed it, but to hear the whingers after the show it must have been awful. Maybe I went somewhere else? We seemed to meet so many people that we barely got all around the show where I at least found plenty of interest. It was particularly good to see the resurgent interest in single seaters and to see all the younger faces of the hanglider and footlaunch crowds, as wise old Deepak (sorry Deepak, wise but not so old) said, “they are the future microlighters”. One of the special meetings was with the guys running Grass Strip Aviation, the importers of the Fokker Eindekker replica. They turned out to be some of the fellow Tiger Cub restorers that I have been corresponding with for the last couple of years. As a result of this I was able to send one of them a disc containing all my Tiger Cub information. If this helps more of the little beasts back in the air that would be a result as my latest copy of the MF reveals the sad news that none are presently in permit.

That stiffened my resolve and I returned to my spanners once again. Things start to come together the drip tray is completed and has its polythene curtains fitted.

Turning my attention to the front fuselage section I bolt the tank rails up firmly, hang on the tank and the two fuselage sections are ready to unite.

Back to the beginning: Project Tiger Cub Story part 10

Paper, paper! and a little bit of wood

Meantime on the SP front, the work carried out had been mostly paperwork. There had been a time that I had thought the old saying that “ No aircraft shall fly until its Maximum All Up Weight is equalled by the weight of its paperwork” was an exaggeration.

Not so, it seems if anything to be an understatement as I wade slowly though the textbooks and masses of web information to answer the points raised by the Tec Office the heap of paperwork!information and references steadily grows. The trouble with such searches is the time it takes. I can spend a couple of hours with the spanners in my workshop and achieve a fair amount, but 2hours of internet search or 2hours spent going though reference books and the end results are very small.

So recent events modified the intended work on SP in a couple of areas. The first one concerned the seat belts, with KT for the first time I was able to sit in a complete Tiger Cub cockpit, well, complete if you could ignore the instrument panel resting on your knees. The seat belt situation was far better than I’d have believed possible, mostly due to the fact that the seat was suspended on its own harness and so sat differently with somebody in it. Not having to alter that would save masses of work and potential hassle from the lads in the Tec Office. The other decision was to mount the fuel tank to comply with the mandatory mod on standard Tiger Cubs rather than stick with the Romain version for which I had no paperwork. I could foresee problems ahead if I stuck with the Romain mod that had pre dated the standard mod, but on the other hand I had the paperwork for the later mod and I had two examples of how it should be. So it would seem to be better to go with the flow.

For the sake of what little remains of my sanity I needed to take a break for the computer and books and with a feeling of great relief I took up my spanners again. I returned to the workshop and SP. Having made the decision to go with the standard tank mod rather than the Romain one putting that in place had to be the next job.

First I had to remove the front cockpit section that I had temporarily fitted for photos to show the Romain Mods of the side glazing of the cockpit and the bottom hung door. Interestingly the Tiger Cub as originally made had just a gap and no door was fitted then people started doing their own thing. Jim Romain had designed his bottom hung door; others had hung them from the side tubes. This in fact had been the cause of a fatal accident when a door opening to the rear had swung open on climb out and the aircraft had gone out of control. After that any doors fitted opened towards the front, as was the case with KT.

Anyway, photos taken and the front section had to be removed again to gain good access and the top of the blue foam that formed the top of the fuselage had to be cut back. Jim had fitted his inside the fuselage but the mod showed the tank top level with top of the foam so I had to comply with that. Next job was to make up the drip tray. That shouldn’t be too much of a problem as I had the drawings plus two complete ones to work from. The tray itself was made from thin birch plywood and coated with epoxy resin. Well that shouldn’t present any problems, resin I have and thin birch ply is available at any decent model shop.

It proved a bit fiddly getting everything to fit as the whole thing was mounted at a strange angle designed to tip any large spillage of fuel clear of the blue foam. Not a bad thing that though as petrol melts away the foam, and the idea of flying an aeroplane with its fuselage gradually dissolving is not attractive to say the least.

I worked away steadily with a very sharp knife making the peculiar angles that were needed to get a good fit. It was quite engrossing work and took for longer than I had anticipated.

Then, all the pieces lay complete on my bench and I made a crude jig to hold all the parts while they were glued together. Finally fixed into one piece I offered it up to the rear fuselage, success, it fitted just fine.

Drip tray in place Then I had to fit the forward bulkhead as specified in the mod, but as this was simply made from blue foam it was soon done. A trial fit of the tank, just to be sure there are no lurking snags then I will ready to fit the tray assembly. Then after resin painting the tray and fitting the polythene skirts to protect the fuselage sides and the rear bulkhead and I will be close to re-uniting both sections of the fuselage. That will be a great day.

Back to the beginning: Project Tiger Cub Story part 9

A surprise gift and a little bit of history

Then out of the blue I get an offer that I can’t refuse, a complete Tiger Cub and trailer hangar FREE. All that and no trek to the frozen North this time, this one is at Eltham less than a hour away. I arrange to go for a look with Joan one evening. It’s dark by the time we arrive but it easy to spot which house, it’s the one with the large scruffy trailer on the drive. We knock on the door and are answered by a short figure with bright intelligent eyes that sparkle at us though he glasses. Hello, he says, I’d hoped that you get here before dark. It’s there he says pointing at the trailer, I don’t know what you are to be able to see, I had hoped that you be here before dark he reiterated. I’m Ken he says shaking hands as we introduce ourselves. We got our little torch from the car and peered into the trailer to reveal a totally complete little Cub her registration GMMKT shining on her tail. She has two flat tyres and some of the fabric seams are peeling, that apart she looks in good shape considering that she has sat in her trailer for better than 20 yrs. Retiring inside we learn a lot more. Ken, it seems is a retired engineer who worked much of the time for the MOD,. he then worked offshore. He still has a JAR PPL which he uses to fly the occasional Cessna.

Ken told us that KT was built by him at the end of unregulated microlighting so there were no build inspections. To gain her permit he sent her to the MBA factory for test flying. While she was there awaiting flight the factory went under. So he brought her home again, then he started his offshore work and so missed the time where Russ Light formed Tiger Cub Developments to support the little biplanes that he liked so much. Russ then moved on to the two seat version, the lovely Sherwood Ranger and poor old KT had missed her chance. A call to the BMAA confirmed there was little or no chance of KT ever getting a permit. As Cubs were a jig built kit though it seemed that she could be used as a source of spare parts in the rebuild of another Cub, KM for instance. So I guess at least most of her would eventually get to fly.

OK, next problem, how to get her home and where was that home to be? Both were solved easier than I’d have believed. Firstly, at Joan’s suggestion I rang Tony HS, Hon. Sec. of the Essex Microlight Club. Tony volunteered straight away and he was perfectly suited to the task. As an enthusiastic caravan owner he had a car that was well matched to the job and had a huge amount of experience at towing large loads. Finding a home for her turned into a simple task, in three days I’d had two offers. Firstly from Rob at London Colney where by removing the wings I’d be able to store her in the back of Robs hangar and the trailer in the trailer park and secondly an offer from Angie to store her at the farm. It really is amazing how helpful people can be.

The big pickup day arrived, or at least the pickup evening. I met up with Tony at the M25 services. It wasn’t until I got there that I remembered that I’d never seen Tony’s car, his aeroplane yes, car no. Still I suppose that is one of the few blessings of the mobile phone. As it happened Tony arrived within minutes of me so  we transferred all the bits and pieces that I thought that we might need and set off. This time we arrived in daylight and Tony had a good look inside before we set to covering the whole thing with new tarpaulins. This was because the old ones although still keeping the weather out looked pretty rotten and my imagination had us shedding bits of rotting canvas all over the M25 and the Kent and Essex countryside as we trailed disintegrating flags of cloth like the Black Pearl from the Pirates of the Caribbean. Tony checked out the running gear and we were away. We moved smoothly along with Tony showing his expertise and making it all look very easy. All went well until Tony heard that the M11 was blocked so we headed in from South Weald, neither of us knew this route very well but Tony had his GPS so no problem. As we drove the road seemed to get progressively smaller and the darkness started to descend. We knew we were close but despite the GPS the Navstock Triangle got us. This is the name given to the maze of small roads in the area. They all look similar and wind in unexpected directions, at times it is comforting that the roadside isn’t littered with the remains of lost souls. Tony was the master of the situation and reset his GPS for point that I was familiar with and we soon emerged into country that I recognized and shortly after we turned into the farm where Joan had made us a cuppa. And so another Tiger Cub joined the collection.

By the next weekend I was impatient for a good look at the latest addition to my growing litter. So, it seemed were several others. Rob asked that we let him know when we were heading down and Angie appeared as soon as we started to move the trailer.

With a good look in daylight it was obvious that the ply that the tailgate was made of had seen better days and the ply floor also looked a bit dodgy, so it was going to take a bit of care to ease her out of her cocoon. So some support was given to the tailgate and we pumped up the tyres and moved her carefully backwards using chocks to limit her to a few inches at a time.

Slowly and carefully she emerged into the sunlight for the first time in more than 20yrs. She looked good, apart from the fabric edges lifting that we had already noted and the rubber mountings for the instrument panel had died and the panel hung on its wires and tubes.

Now, all these years after I’d seen the Tiger Cub in the magazine I had the opportunity to sit in a Cub cockpit as this was the first complete one that I’d seen since ogling Bob Adams in GMJSU at Cranfield in 1984. It wasn’t going to be easy as the firm alloy cockpit floor was well forward of the narrow opening.

In the years since I envied Bob swinging into his cockpit I’d put on two stone of lard and acquired a damaged hip. Never mind, there is very little that you can’t do if you want to badly enough, and believe me, I wanted to. On my third attempt I swung in more easily than I’d thought, just a matter of getting the method right.

The real surprise was the amount of room and the shortness of the stick. Everything fell nicely to hand especially the neat little throttle quadrant with its well made friction nut. The only gripe I could find was that to reach the altimeter adjustment was a long reach forward. All too soon it was time to yield my place to the next in line. This was Angie, who swung nimbly into place. Well, maybe she’d been watching me, after all it couldn’t just be that she was younger, fitter and a whole lot lighter than me could it? Next in was Joan who looked quite at home and it was a shame but it was out of the question for Rob to get in, he is a big lad and gallons into pint pots sprang to mind. With the state of the trailer it was going to be a hell of job to get her back inside especially as the tail wheel trolley was rapidly dying. This was partially bad news as without the trolley and with the wings folded the wing tips fouled the ground.

Angie had the idea of putting little KT behind her Yak in the hangar so we pulled the big beastie out and pushed the little beastie in with Rob putting all his weight on the engine to keep the wingtips clear of the ground as the trolley fell apart the more we moved it. As we left she looked almost cute behind the big Yak.

What a shame that she can never fly as she is, particularly as there are many nice touches in the way she’d been made, you could see that there had been an engineer involved. Still, combined with GMNKM that will be one more Tiger Cub still flying.

Postscript: We never did manage to make use of KT. Too many other jobs needed doing elsewhere and I donated her as an SSDR* project to a chap in Northern Ireland.
*Single Seat DeRegulation – see [here] for more information.

Working down on the farm

We went down to the farm yesterday to say hello to Hedy, and to do a bit of maintenance work.

The farmer was at work there too, much to the delight of the local gulls.

There’s a tractor in there somewhere!