Monday, 15 September 2014

Aresti 108 maidened!

Aresti 108 prototype
Most UK slope fliers will have bemoaned the complete lack of wind for virtually 2 weeks as we have been sat under high pressure- very unusual for the time of year and frustrating indeed, as we had the new Aresti 108 prototype ready to fly. So seeing that there was an end in the conditions yesterday we dashed across to the east coast of Yorkshire, at Reighton Sands and the prototype was finally maidened! Wind was light, only around 8-10mph but enough to prevent us from having enough doubt or common sense (!) from lobbing off the 3.8kg prototype for it’s first ever flight. However, CG was set at 130mm, about 6mm (scaled up) in front of the position that we fly the Aresti 2m, which was our only attempt at any precautions!
Big plane about to be launched, like a 1/4 scale but with low aspect ratio wings
The elation as this big bird soared effortlessly away was blatantly felt by all, except it seemed by the Aresti 108! She just majestically carved through the sky in a rock steady path. Big planes just sit in the air so steadily, it had presence and cut through the air with such authority. No twitchiness, no bumpiness just creamy smooth progress. Sure we could have done with much stronger conditions to show case its potential but after so much anticipation it was enough to see vindication for building such a large acrobatic slope plane. The size just brings another element, doubts about being too big for anything other than flying in the Alps was immediately dispelled. It doesn’t fly slower but the scale effect makes it look as though it does and even on the coastal hill flown yesterday you could see that it’s going to work on a lot of our hills!

It was also satisfying that the trims were left alone and no changes made- even the thermal setting seemed about right as the camber really made a difference to height gained. This was about the same ceiling as anything else flown before. A dive to check the feel of the CG and yes it was nose heavy which of course is no bad thing for a maiden flight. The roll rate was good but the differential needed a tweak and the elevator with couple camber and reflex was a tad too much, other than that the first ever flight. piloted by Greg Lewis, was exactly what we hoped for. It’s just beautiful in the air with such presence that got everybody’s attention as unusually the slope was quite busy- must be the break in the weather that got fliers out to the East Coast!  
Low pass for the camera!

This is a plane that has real presence in the air!
Next it was my turn for a flight and we moved further round to the North to get a better vantage of the light lift. 
Greg Lewis holding- this shows a perspective of the size of this model as we walk towards a more northerly spot launch
Now I’m just a competent, average flier and definitely no acrobatic pilot but even in my hands it made my flying look good. It was so smooth which now made my big cheesy grin even bigger! It just felt so steady and coming close in, it whooshed past with a sound unmistakable that this is indeed a big plane. It seemed to just plough through and if anything, easier to fly than the smaller Schwing E and Aresti 2m I’d been flying earlier. I had a Mobius cam strapped to my head to film the flight but regrettably in the anxious moments before my flight I had it pointing a little high so no great footage. 
However, even in the conditions we had which needed an efficient airframe, it could cover so much sky and cruise along with ease which considering it’s fully symmetrical section I didn’t expect quite so much efficient use of the lift available. I fly with the same transmitter as Greg (but a different mode hence the prototype was set up on 2 transmitters with slightly different throws) and consequently had slightly better settings for roll, although I had reduced elevator throws, discovered from the first flight. This was approx 8mm up and down.
A few tweaks to the programming!
As predicted for the forecast wind strength increased as we got later in the afternoon and Greg took the Aresti 108 up again for it’s 3rd and final flight of the day. 30g trimming weights were removed which put the big Aresti at the same cg as it’s smaller brother.  In addition the throws were altered in line with my settings. The inverted flying was now pretty bang on. Stall turns with rotation at the top from the massive rudder was impressively round and seemingly in one spot- which was very gratifying as much work had been done on this with 6cm (!) throw either way (30 degrees). One surprise was how tightly it could loop without getting upset. The diameter looking quite small indeed!
All in all, a dream of a first day’s flying that really could not have gone better. Overall the leaving impression was this plane has so much presence- it’s going to be a show stopper in better conditions, I’m sure and that’s exactly what an acrobatic plane should do! 

We shall be test flying at various slopes, building on the valuable information gained today. It might be near you! I keep you posted here, as we’ll also be bringing along the Aresti 2m, Carbon Schwing and new Electric Schwing hotliner prototypes.  

All prototypes- Schwing E on 6s, Aresti 2m and Aresti 108- fantastic days flying!

For those that want more info about the build of the prototype, here they are:

Servos 6 x Hitec HS5496MH, full size 20mm wide and HV, used on all surfaces, including Aero Tow release (well why not!) except elevator, which used a Graupner DES 448 BB, 10mm servo mounted in the fin and regulated with a MPX servo voltage regulator.
Fu-Fix bearing kit used on all servos (including rudder servo mounted in the canopy area) except Tow Release servo.
Battery is Thunder Power 2600mah 2s Rx lipo
Ballast in fuse is 12 of 19mm round, 35mm long brass slugs approx 1kg. Additionally 19mm round brass bar 610mm long in wings, 1.4kg. Total ballast provision is 2.4kg
Total ready to fly wt is 3.8kg and with full ballast 6.2kg.
Nose wt required to balance is approx 200g.

CG flown, 136mm from LE at root.  
Full size Hitecs in the nose, rear rudder servo even has a bearing kit using a 14mm arm for massive rudder throw. Front servo is for Aerotow release!!

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