Something about mostly nothing..

It’s been a very loong time since I won anything, so winning the basic was a bit of a shock to the system. For me it means that this was the result of 5 liters petrol. Think about what 50 liters could do!

But kidding aside, it also helped to have Sean as my caller, even though I still have to get my brain used to flying and audio input at the same time. (2 things at the same time?? Am a bloke, only one thing at the time please, anything more gets confusing!)

Strangley my scores do show what I practised most, very stange…

Loopings, why so bad? Trying to hard to correct heading and forgetting the rest mostly. Should have kept them tighter, more speed, easier to fly.

Roll. Don’t even know where to start. Must have been the worst ones ever. ;-( No real idea, other then that I’m less comfortable going right to left. Needs loads of work for sure.. Also KE is in need of some adjustment, but have not gotten round to that yet.

Now the spins. I know they were horrible, but you try to spin that Yak. It refuses. Simply doesn’t want to. Added to that the fact that I did not want to risk a dead-stick by pulling the idle to far back, and you simply have a ‘spin’ that does not want to start until you force it. With full up elevator, it simply rocks the wings and start coming down. Adding rudder, it goes into a wingrocking circle. Blipping the throttle, not much luck unless to really give it a good blast. So, yes, they were bad, and need some tinkering! I tried today with even larger elevator movement (60 degrees). No luck. Rudder is already at full deflection. So, tricks are needed!

Other then that, I think I will try a larger prop (23*8) to see if I get some more pull. Today I did some prophanging, and even though it hangs nicely, I need almost full throttle to stay there. It certainly does not have the ‘oomph’ of a MVVS-85 (Evolution for those so inclined) But that has been the story all along, weight. At present my options for further weight-loss are limited. Most anything that could be replaced/chopped or removed has already been attacked. The only options left now are in the engine department, lighter prop, lighter spinner, lighter ignition battery, lighter tank (less fuel) I now have enough fuel for 20 odd minutes, which is a bit of a waste for a 2 minute schedule. (Need to be smarter next time, Don’t fill it up!)

Of course, I could replace it with a MVVS-a_bit_bigger, but do I really want to? Maybe better to learn how to fly this one as it is..

One thing that has improved the wing trim is adding some heatshrink on the wingtube. The tube is now rocksolid inside the fuse. In the past, you never knew where the wings would go, and that resulted in endless trimming sessions, that would have to be repeated next time the wings were fitted. Luckily the wingtubes are a better fit.

I also made a jig for checking deflections on ailerons, to make sure both serov’s track, and give the same deflections over the whole range. (don’t beleive for one second that any two servo’s with the same input will give the same deflection. It’s electronics!)
Of course I did the ailerons on the QQ-Yak, but I think I will do the elevators on this one next. Using two bits of wood taped to the elevators suggest things are not too bad, but a bit better never hurts.

It’s been a good week all in all, lots of things learned, lots of opportunities for improvements.

This has been a long month. Started off with some strange bug that floored me for 2 solid weeks. Gave me plenty time to practise the schedules in my dreams. Then a week from barely able to move, to tinkering about. That gave me more time to prepare machine and man.
Then, last week, the stuff of dreams, the weather changed to something I remember from my childhood. Sunny skies!

No time was lost to declare that I really needed another week to fully recover, since I was in no state to fly. (That’s my benchmark for being healthy, and my GP agreed!)

I thought I wanted to fly the comp with my QQ-Yak, so I put most efforts in that.

Tuesday: Absolutely no oomph at all, I can barely do a looping, let alone anything else. Decide I have to change the exhaust system to what it originally was. (The QQ-Yak geometry had forced my to use an extension on the exhaust port that was actually too small for this engine, throttling it considerably. Earlier in the year this never seemed to be too much of an issue, so, if it aint’ broke, don’t fix it. ( I’ve not looked at the head yet, it might be that the outlet valve is clogged up.) Anyway, time is pressing, dive into the box of bits and see what can be created.

Most of the bits that ‘could’ be used are aluminium, the YS puts out a fair bit of heat at the exhaust port, so, alu-solder it is. Got some from B&Q stuff, melting temp appears to be right. It’s for ‘soldering alu window frames’ etc. I’m not too convinced, but then I would not expect it to say ‘fix airplane exhausts’. After a bit of cutting and bending and filing I have something that looks like it could work. Soldering (for lack of a better description) Alu is fun, because it’s melting temp is very low, and you can’t see it’s about to collapse into a puddle. Add to that different kinds of alu, different sizes etc, and it becomes a ‘I’m not too happy with this, but its still one piece’.

Wednesday: 3 flights, and the exhaust bits unsolder themselves. Mostly due to obvious ‘cold’ joints. Definitely more ‘oomph’ , we are on the right path. However, despite considerable differential on my ailerons, I have the sitiuation (or so I think) that a half roll to the right needs considerable left rudder to keep things on track, while a full roll appears to go straight. Tried aileron-diff the other way, tried it every way. Can’t work this out in a hurry, and decide to compensate with rudder for the time being. Later, when putting the plane in the car I notice a strange gap in the rudder.. Can’t be true, hinges pulled out?! In hindsight, I used PU glue (just to try) to stick them in. This was a Bad Mistake!  In other words, I wasted a lot of time trying to compensate for a loose rudder
Since the big Yak was there too, I decide to do as many touch and goes as possible, to get over my tipstall fears. 3 20 min sessions of continuous touch and goes, and I am convinced that loosing that extra pound has reduced my wingloading enough to make things ‘happy’. I also note in the back of my mind that it flies the schedule much better then the QQ.

I know I used proper alu-rods before, and hunting around I find them (or something similar) again. But will they arrive in time? For time being I decide to use some JB weld to stick bits together, I might get a few flights out of it.

I also spend an hour considering putting my MVVS 26 on it. CG might be a slight problem, for the rest it should be possible to make the conversion. Estimated time: at least a full days work.  Decide in the end not to bother, I might end up with nothing.

Thursday,  Yes, indeed a few flights. 2 exactly. But, I’m still don’t get the feeling that the YS delivers what it used to. Could it be finally cooked? (I got it second hand in 1998, put a new 1.40 head on it at that time), It was always quite powerful. Now it looks like a 1.10 delivers more punch.

Big Yak is doing well, however the prevailing winds make it hard to practise a full schedule both ways. I resort to doing the individual turn around sequences up and downwind, and since the bits in the middle are straightforward loop/roll etc, they should be ‘easy’. Those end bits need a lot of practise. The stall turn is difficult, I have to keep almost full throttle to just before the stall. Any earlier and it becomes a mess. Time is short, make the best of it.  With the aid of my newly designed spreadsheet, I readjust all my TX-curves, making ail/elev softer around neutral.

On the supposedly last flight I notice on takeoff that my rudder is looking funny!? Chop the throttle and on closer inspection I find the rudder hanging on one hinge. Oops. This reminds me of a story where someone lost an elevator, under slightly different circumstances, but still. I count my blessings and decide to head home for a quick fix.

Friday:  Wow, Alu-solder arrived! Get out all the tools and try again. One of the supposedly great things about this stuff is that it can cover holes. And boy, I need that! Ever so carefull, I start building up and gluing all the bits together, and after an hour I do have a pretty solid looking exhaust! I’m not going to polish it, just get on with it. On the strip just after 1 o’clock, and all looks very promissing. Full power for 10 mins and nothing comes unstuck!  Check the needle again for full power, it’s producing a lot of smoke. As always, turn it rich, and then carfully lean it out till just before max RPM (using the tach) All looking good. Takeoff is fine and then 6 feet in the air, engine chokes. Juggling the throttle does not help, it’s going in the direction of terra_too_firma with no speed. Doing the best I can I have to watch the undercarriage doing it’s bit. I can see it happen in slow-motion. The legs bend backwards by about 3 inches, then a load crack. and the cowling takes the rest of the hit. On inspection the damage is relatively minor. The U/C mounting plate broke where it is supposed to break, no other damage to fuse. Cowling is a different matter, but nothing a few bits of glas can’t fix. But, it’s Friday, and no chance to get that done before tomorrow.

So, it’s Friday, 13:30, and only the Big Yak is flying well. So be it. Go for it. I manage to burn almost 3 liters during the rest of the afternoon, and then something that has never happened before: I ran out of Petrol! Given that in the past it has taken me months to empty a can, I could not believe I went through a full 5 liter can in 2 days. Ah well, it’ll have to do.

Saturday 0600: Off to NewBuildings, where I arrive in a dense fog by 0900. The rest of the story is elsewhere.
At least I’m now totally convinced, big planes do fly better. I’m letting the QQ rest for a week, then see what I will do with it. Regardless, I will strip the engine, to find out why it’s performing so miserably.

Moral of the story? There most certainly is one. I’m sure you can work it out yourself.

pics to follow, got to get ready for another session this afternoon!