Monday, 23 September 2013

Videos of the 'Brit Schwingey' maiden test flights

Brit-E-Schwing from Jonathan Wells on Vimeo.

Brit-E-Schwing-TFu from Jonathan Wells on Vimeo.

The ‘Brit Schwingey’ has flown and it was better than we had hoped for! Here are some videos, they don't really do the speed justice, look at what happens when diving straight down from height- well it certainly felt faster (and scarier) than that! 
We had a 6hr outing and I can’t say I’ve had a better or more memorable flying session, never mind this being it's maiden test flies! We flew off a slope in light Westerlies probably no more than 10mph and very little thermal activity and conditions so poor for sloping that a big 4m Ash we shared part of the day with struggled to get away and only managed to get high enough before the worried owner cut his losses and came in to land. 
We, on the other hand, we’re having a ball- the best way I can describe it is as though we were on a fantastic hill and best thermal passing through but continuously! 
It wasn’t like that on the first few flights which was trimming and altering the cg and crow brake settings.Here we were just testing the motor on climbs and dives until we had the plane trimmed- now that was fun with big dives down with a few antics on the way down and a few loops and rolls until the speed bled off.
On the glide for the conditions it felt like a heavily loaded plane at 2.4kg which it is but as the speed got up it felt rock solid. Then I started to merge the power with the glide not to gain height necessarily but to kick the plane with more and more speed especially at the ends of each pass across the slope. The fun really started! Once it got going it just needed a blip of power to get faster and faster. We did the big loops right in front of us powering on the bottom and climbing up then off as it went round and it just speeded up with each revolution. It just felt like DS’ing! Flying the power like this just made a poor slope with poor lift far more entertaining. The props folded pretty much immediately so it could be dived as soon as the power was off which was then seamless flying between power and glide. The videos just look like a Schwing on a good day, on a good hill, only it wasn't and you certainly couldn't throw around a heavily loaded glider in the way we were on just slope lift. I guess having this capability is the whole point of flying electric for ,me.   
Jonathan Wells, our local wonder kid turned up late afternoon and put the Brit Schwingey through it’s paces. It wasn’t all perfect, the power on did produce a climb with the plane wanting to do a massive loop but it wasn’t too bad and it wasn’t crazy amounts of power but looking at my tranny timer we were getting around 2 mins power on with each battery before you could tell the motor beginning to flag, which is much better than expected. Back in the workshop looking at the Castle Creations logging it was clear we were getting between 1500 to 1200w in the air and about 60a current draw average. This was confirmed with the charge back into one of the packs which was around 2000mah so dangerously close to fully depleting the 2250mah pack! Each power on was only short the longest being about 3s and usually just a second or so. If you recall the static test showed 1971w with a pack straight off the charger. I guess the lower power rates compared to static is that the way it was flown fast meant that the prop had less load on the motor.   
Even so when checking the packs and motor on landing they were barely warm. a sure sign that nothing was stressed. Certainly the power system is under propped but it was just effortless speed at will and the last few sessions was just prolonged aerobatics and F3F style racing at break neck speed! I'll leave it for others to tune the power set up to get the maximum power. We'll try a 3s set up next with a second prototype around 950w static, still a decent amount of power but lighter (I reckon under 2 kg) and less frightening for us slope boys, not used to high power E planes! 

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