Month: May 2016

Deer and Skylarks

I thought it was just going to be me, the deer and the skylarks for a while this morning as the weather was cold and windy. The grass is just starting to grow again, and there were hundreds of skylarks swooping around, which is really good to see as we were beginning to worry that they were dying out.

As it turned out, there were some people flying a DJI Phantom some distance away, then a UMX Champ came across by electric bike, followed a little later by a very nice gentleman with a DJI Phantom 2 and then finally we had somebody with a Vortex racing quad (with very dodgy PID values).

I also got an answer to the problem of the UMX Stryker and SpaceWalker crashes of a couple of weeks ago. While we didn’t fly the Champ because of the wind, he apparently now has a new Carbon Cub, which he was having difficulty setting up. His Spektrum radio refused to bind and, on further inspection, it turns out that the antenna wire was broken. This was the radio I was using with the Stryker and SpaceWalker, so almost certainly explains the loss of control I had with both. It was probably working intermittently, with complete loss at certain orientations. In the case of the Stryker this just had to be when it was heading vertically downwards, resulting in the crash.

As for me, I’d had two flights before anybody else turned up. The deer are completely un-bothered by the plane and just stand there watching it flying around them. I had 5 flights in all, one where the battery cut about 3 minutes before I was expecting, so it might finally be time to ditch the original LiPos which are now over 3 years old. It was really windy and turbulent with the direction blowing straight through the trees lining the road, which is unusual. I had a bit of a practice of the harrier manoeuvre, but it was really too windy. You can do it if you slow right down to the point where it goes ‘mushy’, then power into the 45 degree nose up attitude. At that point you can see me over controlling it with the ailerons to try and keep it in the harrier while all around a gale is blowing up. I need to do some more 3D setup with the RS352 as it needs more elevator movement for this type of manoeuvre. A finer pitch prop might also help, as there isn’t enough control to be able to hover without the huge thrust powering it skywards. I did just about manage the hover and quite a good prop hang as well. I think I need to go back to my radio setup now and make a few changes.

OK, that’s it for flying this week. Tomorrow is a Bank Holiday, so I’m going to try and finish up all the little jobs that are left on the AutoGyro. That means covering it, so it’s time to hunt out some really bright profilm.

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Close Encounters with an Easy Star

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Spot the Easy Star?

It was quite a nice morning again this week, so there were lots of people flying. There was a guy on a bike with a 150 sized drone (no FPV), flying loops and rolls when I turned up. Also, the DJI Inspire which had just had a new firmware flash to fix a video problem from the previous week and was in the process of being flight tested again. I’ve never looked too closely at the mechanism before, but when it’s sitting on the undercarriage about to lift off, the rotors are tilted inwards slightly. Then, when the undercarriage comes up, the rotors tilt to a slight outwards angle for flight. I wonder what this transition does to it aerodynamically?

Anyway, after that we had a foam flying wing FPV and Vortex Quad, then the UMX SpaceWalker, F27 Stryker and Beast on a bike. I had a flight with my own RS352 before attempting the Stryker again, which was the one I crashed last week now repaired. He had stuck the nose back on and used fibreglass tape for the damage to the shoulder. We went though checking everything, including a range check, and I elected to fly on the high rates this time, knowing that I could flick the switch back down to low rates if needed. It flew beautifully, I even remarked part way through the flight that, “I think I’m flying Concorde”. Actually, it was rolling right quite badly and dipping into the ground, so I found a good throttle point to fly level and progressively added left and up trim until I was happy. About 6 left and 2 or 3 up did it. It’s not an easy plane to fly because you have to balance the aileron and elevator when turning. Too much aileron and the nose drops too much in the turn, the elevator won’t pick it up and you have to back off the aileron or screw into the ground. This might be a control harmonisation thing (needs more elevator?), but I’ve only flown it once so far. After checking the response to power off and glide, then going through some aerobatics as the confidence built up, we decided that landing with power was a good idea and brought it in after about 6 minutes. The landing was a nice flat glide, with little or no flare, as you expect from a fast aircraft like this, speed coming off nicely until it plopped down in the long grass in front of me. This is where it gets a bit weird, as I thought it had AS3X stabilisation as you could hear the servos chattering away, although the surfaces weren’t moving in any way I could see. The owner didn’t think it had stabilisation, so we looked on the box – it doesn’t. Now I’m worried because this might be what the problem was before. What’s causing the chattering noise if not the stabilisation? It can only be servo noise which suggests an electronic problem. Maybe I got lucky this time and the radio worked through the whole flight, but I’ll have to check it out to see if this is normal for a Stryker before flying it again.

I managed to get 4 flights in with my RS352, plus another one with the UMX SpaceWalker from last week. I think it is still suffering from radio problems as well, as I spiralled it into the ground again and bent the motor shaft a little bit. Determined to get to the bottom of this aircraft, I went up again and was very careful to fly without using any big control inputs. I just nudged it around the sky very carefully, or at least as carefully as I could now the wind had increased and the aircraft had trouble moving forwards against it. I was flying it like a quad at one point, with the right stick forward to penetrate and modulating the power. What I’m wondering is whether there is part of the flight envelope where a big rudder input causes the aircraft to suddenly flick in that direction, maybe the structure flexes as well, but then no recovery is possible? After all, it’s just a simple rudder elevator model with huge dihedral and comparatively little rudder movement. I need to try this out on a calm day and see if I can cause the problem deliberately. On the other hand, it could just be the radio. It did definitely fail last week, but not at all on the final flight today. It’s still a 30 gramme mystery.

We also had a new guy with an as yet unflown DJI Phantom 3, some guys were also flying two Phantom looking quads at the edge of the field near the stream, then a guy with another FPV quad arrived. Next came two Multiplex Easy Stars with FPV, the Hobby King Bixler which had been modified with removable wings and tail but had forgotten the radio and couldn’t fly, then finally a guy with his family and a FunCub arrived.

The title of this post comes from the flight of one of the Easy Stars, where he hand launched it, it did a big low right hand turn 180 degrees, flying 6 feet over our heads and then arcing into the ground behind us. If you look carefully in the picture above, it’s just over one of the trees in the middle.

OK, next week is a Bank Holiday so I need to get the AutoGyro flight ready. I’ve done nothing on it this week because of work.

Strike Three

It was quite a nice morning this morning, with lots of people turning up with interesting aircraft, but I managed to crash two models and watched a Hurricane spiral into the ground.

When I turned up we already had a UMX SpaceWalker and F27 Stryker, the only problem was finding a battery that worked for the SpaceWalker and trying to attach it without any velcro or tape as neither of us had brought any. I eventually secured the battery with an elastic band around the fuselage and we went off to fly it. I’ve flown this aeroplane lots of times so I’m quite comfortable with it, but on a couple of occasions I had tried to turn back towards myself and nothing happened. With a model this light it isn’t that unusual, but there was another period when it flew over our heads with no control before the radio picked up again. Now, I was circling at a sensible height right in front of myself when it suddenly drops the right wing, I go with it and pick up 360 degrees around the turn, then the left wing drops and it goes into a spiral that I can’t recover from. Naturally I had cut the power at the top, so there was no real impact with the long grass helping out, so no damage was done. Inspecting it on the ground, everything still worked and the battery was still wedged in the correct place, so I don’t really know what happened.

Next, we started to set up the Stryker, which isn’t something I can remember flying before, but I’m a lot less worried flying something quick and aerobatic with plenty of power than I am flying the UMX Champ or SpaceWalker. We had another problem with batteries, but at this point also noticed that there was quite a large quadcopter parked over by the river with lots of people around it. We had been having a discussion about whether it was a table or quadcopter, but seeing it fly suggested that it was probably not a table. Anyway, we had a strange problem with the Stryker, where it turned on, but none of the controls would work. Disconnecting the battery and reconnecting it seemed to do the trick, so we launched it by holding the left wing and doing a discus type launch. This would have been fine, except that the battery chose that exact moment to give up and the BEC cut the power. I did the only thing I could and hit the grass flat, so no damage was done and we switched to a better battery. The launcher chose to do the next throw by holding the fuselage underneath, which put his fingers perilously close to the prop, but he said he usually did it this way, and it proved to be fine. The Stryker climbed away with me decreasing the power to stop it going vertical until I was far enough away that I wanted to turn back. I wanted to roll right and fly back past myself, but once the wing went over and the nose was pointing down, the elevator was completely unresponsive. From a 30 degree climb, I had rolled 180 degrees right, let the nose come down to point at the ground, zero throttle as I’m heading down at this point, then a little elevator to pick up the nose. Nothing happened up to the point where I hit the floor with full elevator. The only thing I could think of was that there was too much pressure on the elevons from blow back, but the speed was nowhere near enough for that to happen. On inspection of the crashed plane, everything appeared to be working, but the nose had taken the brunt of the impact and broken in two places. It should be easy enough to stick back together, so it will hopefully fly again. The only weird thing was that both aircraft suffered what could have been radio failure in exactly the same part of the sky.

As for the rest of the morning, I had four flights with my RS352, getting what sounded like applause from the people with the quad as I flew up and down that side of the field. We never really saw them fly it much, apart from pottering about a bit in the hover. There was another guy with his two kids who also turned up around this time and proceeded to fly down the other end of the field with an Easy Star clone. The first flight it seemed it could only turn left and spiralled off down the field, nearly hitting a tree and landing the other side of the river. The second wasn’t much better, but it was still flyable, so I went over to help them. There was too much aileron movement and the centre of gravity was at more like 50% than 33% and the canopy wouldn’t stay in place. Having seen him fly it before I did fly it for him, although I was a little reluctant with the C of G. The model is actually an Axion Alpha 139 from Ripmax (in bright orange). So, my flight was a bit hairy with it rolling left quite badly and the rearward C of G causing problems. I did a number of circuits and managed to do a classic pitch oscillation before bringing it back round for a perfect landing. I suggested he try and find some weight to put in the front before trying to fly it again, but there was nothing we had to hand.

This is the point where I went back to the middle and we watched the Hurricane taking off from the ground. Two other guys had turned up by this time, one with the Radian glider from last week, plus a new Squall HP ducted fan jet made by Phase 3 which he got in a charity shop.  The Hurricane didn’t quite make the first take-off, ripping large chunks out of the ground with its propeller. Undamaged, but with a bent U/C leg and missing tail wheel collet, I managed to find a replacement for a 2mm shaft which worked to hold the wheel on the much smaller metal wire. All it needed to do was hold the wheel on and it’s really annoying not to be able to fly for the sake of a tiny collet to hold the tail wheel on. Anyway, take-off number two was better and the Hurricane flew around for several minutes, with its main U/C legs still down because they were bent, until the pilot decided that it was time to land. At this point he managed to spiral it into the ground at almost exactly the same point that he did it before Christmas. Surprisingly, only the right wing was snapped with some superficial damage elsewhere, so it looks to be perfectly repairable. When I flew the aircraft before, I think the controls were too sensitive for the speed. It feels heavy to fly, so you need to keep an eye on the speed, but the sensitive controls make it easy to stall if you’re not careful.

I suppose the title for the post should really be “four strikes”, because the Squall HP also ended up broken, but it was whizzing around the sky like a demon up to that point. He could hand launch it quite easily, but there is a noticeable dip towards the ground before getting on step and flying away. The first landing was a bit abrupt when the ground jumped up a bit early on finals and took the pilot and all of us watching by surprise. The last flight was more of a thump into the ground, resulting in it breaking, but then he said it cost him nothing and the foam is easily repairable.

As I was leaving the guy with the Fly Baby was launching a glider, plus another father and son were flying around with a Fun Cub.

All in all it was a very busy morning. I’m rather aware that the AutoGyro really needs to fly, so I’m thinking about the Bank Holiday weekend in a couple of weeks. I stuck the canopy last weekend, so all that’s left to do is the installation and controls. The pictures are below, which look almost identical to the last ones, apart from the fact that everything is now stuck and all the gear is trial installed inside the fuselage. I just need to stick things down with velcro and route the wires. Covering it and balancing the blades are now the two main jobs remaining.

Hot and Sunny with Bumpy Squirly Bits

It’s hot and sunny this morning and it wasn’t until later on that the wind became really stupidly strong, so it brought lots of people out flying today.

As I arrived there was a dad and his two boys just leaving after not being able to get the power to work on their foam high wing trainer. They’d seen me flying before, so stayed for a bit to watch my first flight with the RS352. There was no wind at all at this point, so it was very much a trimming flight with long slow aerobatics to see how everything was performing.

I had noticed three guys dragging a trolley with two big black boxes across the field and, sure enough, when they arrived it was a couple of DJI Inspires. They looked like they were doing their permission for aerial work with the pilot log books they had. Also as I was arriving there was the American guy who used to fly a while back in the wind and rain with the foam Cessnas. He brought his wife with him and went way down the other end of the field to the shade of the small tree and proceeded to fly a V-tail electric warmliner glider all morning. After that we had another DJI Inspire, then the small UMX SpaceWalker that I often fly with his son carrying another big SpaceWalker, Parkzone Radian glider, Fun Cub, small Cessna, Lazy Bee (with big eyes) and a free flight West Wings model that we had some fun trying to fly in the wind. Also, there was the E-Flite Advance with a big foam glider, another guy with a Radian who had to ask directions to the car park and a whole host of other drones who never came near us. One of these guys was flying what could have been a scale Apache helicopter, but we think he was the one flying the dark and white coloured aircraft last week. There was also a father and son with a DJI Phantom which almost came over.

As for the flying, I had 4 flights with the RS352, with the later ones in really windy conditions. On one landing I ended up upside down as the wing caught the wind side on at the last moment and flipped it over. There was no speed at that point, so it didn’t do any damage. The final landing was also a bit interesting with me having to use about 50% power and really fly it down to the ground. The flare then resulted in the aircraft catching the wind and launching 10 feet into the air. An almost perfect landing only resulting from quick application of all the control surfaces and throttle.

The big SpaceWalker looked fantastic in the air and its extra mass really worked in the conditions. It could hold the momentum through manoeuvres where my RS352 was getting thrown about and losing all forward speed. The Lazy Bee also looked good, but had a motor problem part way through the flight and had to be brought down. This took quite a long time to get back down to Earth and shows that these things really glide well. It reminds me of the time I was flying somebody else’s one and it wouldn’t come down for about 45 minutes despite looping and spinning it.

That’s about it, apart from saying that there were so many models this morning that I forgot to take any pictures. My ATOM autogyro is also nearly ready. I’ve been measuring the head movement and found that it’s about twice what it needs to be, so that’s not too much of a problem. I’m going to try and glue the canopy together later while there’s enough light to see what I’m doing. Hopefully that will be flying soon.

Normal Service Is Resumed

After everything that’s been in the news recently about a drone hitting a plane on the approach to land at Heathrow, they’ve now decided that it was a plastic bag instead. At least it didn’t turn out to be one of the drones from the BBC’s aerial filming unit then. Given the amount of drone footage that turns up on the TV now, they seem to be flying them all over the place.

It was quite a pleasant morning, if you don’t count the wind and low level turbulence. When I got to the flying field this morning I bumped into somebody who I haven’t seen in ages, along with 2 generations of his family and his dog who loved to chase all our aeroplanes. He had a home-built foam profile plane, but couldn’t fly it because the prop attachment broke. It was really good to see him again. We also had a guy with a foam board Spitfire that he built from some Internet plans, plus his DJI Phantom, the guy with the eFlite Advance and Multiplex Heron glider who arrived shortly after me, plus a couple of youngsters with a DJI Phantom who arrived part way through the morning. We also had a visit from somebody else who I haven’t seen in ages who used to fly a Magnum, plus the guy whose Hurricane I flew before Christmas. He arrived on a very high tech looking electric bike and it was good to hear that the Hurricane hadn’t sustained any real damage from when I dropped it straight down on it wheels quite hard on landing. There was also a father and son who were flying some sort of really small dark aircraft and a bigger white one at the extreme limits of the field. It was hard to see, but the white aircraft seemed to be going very well. Nothing compares to the Spitfire flying straight towards us and turning away though, I never get tired of seeing that in the air (NOTE: you need to build a Tempest).

Other than that, I managed five flights with the RS352, checking the prop adapter after every flight with my coffee stirrer feeler gauge. The prop adapter is still gradually sliding forwards, but I’m not sure whether this has now stabilised, or whether it’s just the manoeuvres that I’m doing. For the later flights I cut out the prop hanging and flick rolls, so it might be that. The motor is still making more noise than before, which certain people said was better because they could now hear me coming where the aircraft was almost silent before. For me, silent means efficient, so I’ll keep checking for problems. Despite the conditions, which were laugh out loud bumpy – one minute you’re flying straight and level, then you’ve gained or lost 20 feet and in a knife edge, it was a lot of fun. One landing I really was going sideways, but still hit the spot. It seems to me that the power on balance isn’t quite there as I’m having to be much more cautious with the throttle than I was before the motor fix. As soon as I power back up after a loop, you can see the aircraft wanting to torque roll and yaw which wasn’t happening before. The thrust line is a bit off, probably due to having to drill out the cocktail sticks and then replace them to get at the motor. I’ll fix it eventually, but I need some calm weather for trimming. It’s perfectly fine flying along straight and suddenly pulling full up into a vertical climb, so I’m sure it’s not aerodynamic.

That’s enough of the flying for this week, but it’s a Bank Holiday, so in amongst all the work I’ve got to do, I need to find some time for the ATOM Autogryo installation.

It’s not looking too bad and I’ve got the waggly bits of the head waggling when I move the sticks on the transmitter. I think it’s just the radio and final installation, rudder closed loop, covering and rotor blades left to do. The rotors are built, they just need final balancing and covering. My main problem is with the rotor head angle as I don’t want to cut too much off of the push rods, so I’m thinking of using my smart phone as an inclinometer to measure the angle. I also need to work out how to hold the canopy on, but sellotape would do it for now.

Just to finish, we had an interesting discussion about ornithopters this morning and I mentioned this video on YouTube: [Pterodactyl] This is the funniest thing I’ve seen flying in a long time as it looks like a duck in flight. Once I tick autogyro off my list I’m moving on to ornithopters.