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Time for me to step up a gear in electric flight


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Wow! What a cracking morning today turned out to be, plus a brilliant maiden session! The weather forecast wasn't as predicted the night before as the wind was blowing 4mph more at nearer 8mph. Additionally, the wind was right across the runway at NW- WNW. Hey Ho! I was there so now to get on with it.sarcastic First the numbers. I used 2 x Hacker TopFuel Lipos 6S at 4500 mAh wired in series making a 12S set up. 20x10E JXF wooden prop from 4-Max.

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Off we go. Elevator needed a few clicks of UP (10x in total) for straight at level flight, 3x of right aileron and 1x right rudder. After a few more flights to be sure I will adjust the couplers/rods. Inverted flight required no real input, although there was a tendency to be slightly nose up inverted. Not sure whether this is why the adjustment on the elevator was required. I am sure experts will tell me why. Knife edge required no extra input as there was no tendency to roll out. All other aeros without out stress and vertical into the stall turn was full of power as expected.

I lost sense of a bit of time and a flicked a glance at the TX timer and it was showing 7 minutes ( I had set it at 8 minutes). Whilst I hadn't detected a drop off in power I decided best to go into circuit mode and land.

Landing, despite the slightly tricky wind direction, was a peach (not all my skill I hasten to add) and the model was happy to be slowed right up without any vices. Simples!

A second flight followed in a similar fashion.

fullsizeoutput_9f5.jpegBack on terra firma and prop covered again, all safe and ready for the next session. Really pleased with the whole experience, so much so I even forgot about the ill fitting hatch cover! smiley

I decided in a fit of bravado, and not wanting to be a Bondaero advert, to fly my MX2 61" despite the conditions not being ideal. Two flights with that and time for home and a barbecue. What better day, Huh?

Edited By Adrian Smith 1 on 13/08/2017 12:36:31

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Hi Adrian, well done on a successful maiden.

You say that when inverted there was a slight tendency to pitch nose upwards. That's caused by your CG being behind the stable point. You also say that KE does not require any corrective aileron. I would ask if the aircraft pulls to the canopy or to the u/c. Moving the CG will affect this issue but if you are focusing on precision aeros and not 3D, you would do better to move the CG forward (shifting the flight pack is all that's needed) a little at a time until you need to maintain a little forward pressure on the stick when inverted. You could also investigate what effect moving the CG even further forward has - does it improve the handling or does it make it worse. The other indicators of an aft CG is a slight delay in spin recovery or, if you use opposite rudder to stop the spin, the potential for a spin in the opposite direction.

CG position is the single most important trimming tool we have at our disposal. Every trim step after that needs to be repeated after moving the CG as this affects everything else. If you have not seen it, the GBR/CAA trim chart gives some useful advice on trimming. You will find it here. That also goes into how to ensure a vertical downline as well as a vertical upline. It generally takes about 20-50 flights with an aerobatic aircraft before the trim is sorted and it flies like it's on rails. It's worth the effort and don't forget to return to it if the aircraft starts to misbehave at any time.

Have fun and enjoy your new aerobat.

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Thank you Peter. Your excellent tutorial has reminded me of the basics that I should have retained in my brain (it was in there somewhere I think). As far as I can remember in KE there was a slight, but only slight pull to the U/C. The one figure I didn't try this time around was the spin upright/inverted. I tend to want to inspect the airframe/bolts etc on the bench before I go back and try those numbers with a new aircraft. Thanks again for you advice.

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