Pilot’s notes

For a number of years at the Sandown show we heard fellow pilots and spectators shout out “Blender!” to Christophe Paysant-Le Roux (perhaps one of the greatest 3D aerobatic pilots of all time) during his demo flights with the likes of the ZN-Line Majestic. The blender is a truly dramatic manoeuvre, especially when performed by the likes of CPLR who enters and recovers at truly low altitude. So, can you do a blender like the big boys? And what’s 3D, anyway?

3D Flying is a term that arguably derived from the heli scene, since only a helicopter can fly three dimensionally by virtue of its ability to perform backwards. As far as fixed-wing flying is concerned we’re essentially talking about manoeuvres where the model is stalled, or not moving forward, in a normal flight path. On top of that certain dramatic manoeuvres, like the blender, get wrapped up in the definition, as 3D aerobatics and artistic aerobatics begin to overlap.

Not all aeroplanes can fly 3D, there are particular design characteristics required to do this well, indeed, we’ll cover that in greater detail at a later date. However, if you have a sports aerobatic model or better, that’s structurally sound and you have the confidence, then a blender should be perfectly feasible.

Some models will perform it better than others but you don’t need a pure aerobatic model to do it. What will help, however, is larger than average flying surfaces. Either way, you have nothing to lose by trying it out with whatever model you fly, providing you’re satisfied with it’s structural integrity and you perform the stunt at appropriate height.

IN SHORT
A short description of the blender would be: Dive at the ground whilst rolling, enter a high speed negative spin, transform the spin into a flat spin and get the heck out of there before you hit the ground… simple, eh?

We've covered the negative spin; you’ll be using the same manoeuvre here but this time you’re entering at high speed and, of course, whilst heading directly toward terra firma. Let’s take it step-by-step and emphasise the critical bits.

So what’s the worst that can happen? Well, if you start or finish the manoeuvre too low, such that you can’t recover the model, then it’s game over! Alternatively the airframe might not be up to the high ‘G’ forces that are inflicted, or, most critically of all, you enter the spin element with too much power. Believe me, entered at the right speed this manoeuvre will look much more violent and stressful to the airframe than it really is. Enter with too much power and it can tear itself apart before your very eyes. Hmm… I can hear knees knocking and bicycle clips twanging even at the very thought. However, don’t be scared, you can do it!

INTO THE ARENA
For the first attempts, enter from straight and level, at a good altitude.
Reduce the power to idle, and before she comes to a stop push down elevator so that you’re aiming directly at the ground. Leave the power at idle. Introduce aileron in your favoured direction, a little at first then crank it up. Depending on the roll rate of the model you may move to the crucial stage before you get to full aileron… hit the negative spin controls we looked at last month, bearing in mind you already have aileron input, which shouldn’t be reversed at this stage.
If you chose a left roll, then to enter the blender you’ll need to sharply throw in full down elevator and full right rudder (opposite to aileron) simultaneously. Whammo!

You should have a violent-looking entry into a negative spin, and the descent speed that had built up in the vertical dive is momentarily halted; the spin will no doubt look flatter initially than when you enter a conventional stalled, inverted spin. That’ll do for now… let it go a few turns and release the sticks to pull out. Phew! Well done, that’s a good start.

CPLR, an arch exponent!

Repeat that exercise a few times and get used to it. If the snap into a spin doesn’t occur then, assuming you put the right controls in at the right time, you might end up with what looks like a spasm of aerial spaghetti with the impression the model is fighting the controls. The cause? Possibly insufficient throw on the surfaces, C of G significantly adrift from where it ought to be, a bit more speed needed before entry, or perhaps your plane just isn’t suited to it. Rest assured though, most sport aerobatic models will perform this basic version of the manoeuvre.

Okay, so that entry speed. Depending on the model you’re flying, you might need to crank up the entry speed a little to get maximum effect. Achieve this simply by entering the vertical dive a little sooner before all the speed decays, maybe add a few clicks of power on the way down, or give the model a 25% (or thereabouts) surge of power moments before you hit the spin controls. My favourite method is to enter slow, increasing the power steadily so as to clearly hear the increase in rpm. On snapping into the blender the power is removed to idle a millisecond after the spin controls are input. I find this often gets the desired effect from spectators. As if diving at the ground isn’t enough you’re also seen to be adding more power and then wham – the violent entry to the blender. The most power you should use without taking unnecessary risks is around 30%, but model types do vary of course. Style is everything in this game as much as the showing off to your clubmates or the crowd. So, let’s develop the blender a little further…

PLAYING TO THE CROWD
Aside from doing everything lower, you can spice-up your blender a little for greater effect. For example, on the downward leg use a few opposite rolls, or opposing hesitation rolls, or both. Performed effectively this can make you appear indecisive or in trouble before the chaos of the ‘blend’ at the bottom.

This next ‘enhancement’ is where model type and set-up become more critical, but you have nothing to lose, so try it! A great way to complete the blender is to convert the high-speed negative spin (which will start to un-flatten and drop again when the initial pace is lost) into a negative flat spin. This can be done in such a way that it’s a seamless blend (excuse the pun) from a normal spin manoeuvre to a flat one, and has the effect of perpetuating the blender and slowing it right down. To achieve this, rewind to the moment soon after you’ve hit all the negative spin controls. As soon as the model begins to slow up, probably within a turn or three, swiftly (but not sharply) switch the aileron input from one side to the other – you may need to experiment with how quickly you make the transition but make it smooth and steady.

Depending on the model this will either achieve a flat and slower spin or it will try to fly out of the manoeuvre, in which case set-up changes may be required, less opposite aileron input, or a different plane altogether! Experiment with different amounts of control input. Anyway, when you’ve switched aileron direction, re-introduce power to keep the flat spin going. This should also keep the nose up and reduce the rate of descent further. Depending on the model, the slower the spin becomes the more inclined it will be to try to fall or fly out. This shouldn’t happen with a 3D aerobatic ship such as the ZN Majestic, Capiche and other such aircraft, which are designed for this type of manoeuvre.

The ‘big boys’ take this one stage further and convert the flat spin into a negative parachute and / or Harrier, just to extend the descent toward the ground and ‘wow’ the crowds; but that’s a whole different ball game, and achievable only with the right aeroplane.