Month: December 2014

Christmas is Coming

Christmas is coming and it’s too windy to fly again. Last week the aircraft got blown over onto its tail and I couldn’t put it down when I was loading the boot of the car, which is a sure sign that you shouldn’t be flying. This week was worse, so it’s quadcopter practice indoors again. That’s probably the end of flying for 2014 now that the Christmas break is almost here. With the break coming up I’m going to do a thorough check of the RS352, finally program the flaps correctly and put some more work into the flight simulator. The following screenshot shows that it’s now flyable (just):

Skylark Javascript flight simulator using WebGL. The aircraft is an ebee flying wing.

Skylark Javascript flight simulator using WebGL. The aircraft is an ebee flying wing.

The aircraft is an ebee flying wing¬†which has been used for remote sensing using 3D stereo vision cameras to map the terrain as it flies over it. I built the model in Blender last Sunday and then went and built a small (~1.5 inch) physical model using a MakerBot 3D printer. The results were fairly successful, but I can’t see myself replicating anything that can actually fly any time in the near future due to the lack of structural integrity. However, the flight simulator is coming along nicely and I now know enough about Blender to attempt converting my RS352 mesh which was originally created with Google Sketchup. The code will be going on GitHub as soon as it’s flyable.

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Run Santa, Run

It seems that there was a Christmas fun run this Sunday, so there were hundreds of people in Santa Claus outfits running along the road next to the flying field. Despite being sunny, the wind was very strong and it was bitterly cold. It’s mornings like this that make me wonder why I do it.

But back to the flying. I was first one there this morning and was on my own for a while, until my friend with the EFlite Advance 25e turned up. It turns out that he had been driving around for an hour trying to find a space in the car park, but all the Santas had got there first, so he had to use the car park miles away and walk around the river and across the fields. He was closely followed by the guy who makes the foam board aircraft. This time he turned up on a bike with a small swept delta flying wing in his backpack. Just like me, he had made it specifically to fit the backpack so that he could cycle over with it easily. It flew really well in the wind as it’s very quick and has an amazing roll rate. Apparently, the wing tips are held on with magnets so that you can pull them off. This probably helps on the landings as they would knock off without damage.

On the subject of landings, my first flight with the RS352 was one of my best landings for a while. In a very strong wind I managed to get it right down to the deck in front of my and hover onto the wheels perfectly. For this aircraft in windy conditions, that’s probably the best technique. Come in fast and steep and use the power to hover it down to the ground. I can’t help thinking of the Eric Brown book, “Wings on My Sleeve” and his technique for landing a Mosquito on an aircraft carrier when the required landing speed is lower than the stall speed of the aircraft. After that I had another three flights with the RS352, which was handling the blustery conditions very well indeed. The last take-off was a bit exciting though, as I forgot to set the flap switch down. I thought it didn’t climb away from my hand quite how it normally does, then realised that the flaps were in the up position with the associated nose down moment. I had been flying with this setting on and off because of the conditions, but I do really need to get the program right to mix out the nose down automatically. Normally I just fly it as it is which is a bad habit to get into.

Just as I was leaving another person turned up on a bike with a DJI Phantom Quadcopter in its hard backpack. I watched him set it up and fly it before I had to leave. The props are interesting the way they screw backwards onto the shafts and are removable so that it goes into the backpack. He did the same as every other quadcopter pilot, though, and took the thing off from the grass much too close to where we were both standing next to the aircraft, with the wind blowing it straight towards us. When I pointed this out, I got the usual, “the electronics keep it in position”, whereby he tried to demonstrate to me that it would stay exactly where he put it. Needless to say, it was drifting dangerously towards his bike’s handlebars, so he had to correct it just centimetres away from breaking the blades. I would have liked to watch it for longer, because I suspect that the weather conditions might be a bit too much for it.

Anyway, the flight simulator is coming along nicely. I would include a screenshot, but it’s not easy on this Linux machine. I’m off to learn how to create an aircraft model for the simulator using Blender. It’s going to be a flying wing.

Heavy Drizzle and the Problems with Glasses

This morning we’re looking at periods of heavy drizzle moving through on quite a stiff breeze, so no flying this week.

Looking at the drizzle falling in the back garden in between the periods of sunshine reminded me of why I’m always cautious about flying in even very light rain. I have to wear glasses in order to see the aircraft, and I remember one day around Easter time when I was flying my own design 2.2 metre electric glider. It was a bright sunny morning, and I was happily flying this bright red and yellow glider with all moving T tail, only to get hit by some light spring rain.

It was only very light drizzle and the Sun was still out, so I ignored the rain and carried on flying.With the rain on my lenses, I found I was having to pick a spot which I could see through in order to watch the aircraft. This was fine until it was time to land and I glanced down at the ground to check distance, looked back at the aircraft and couldn’t find the spot I had been looking through. Everything was suddenly very blurry and I ended up hitting the ground quite hard and damaging a wing.

The damage wasn’t that bad and I had the aircraft flying again quite soon, but the morale of this tale should be obvious – wear a baseball cap! It keeps the rain from falling directly on the lenses.