That is one of the big mysteries of flying and has confused quite a lot of people.
Let's take a trusty old C150 and practice turns around a point as required for a checkride. Normaly there is some wind therefore I have to correct for it every moment of the 360° turn. I start into the wind and do my first 90°. The wind is pushing me toward the point on the ground and I have to BANK a bit less than in a no wind condition ... and so on all the way round. Now, what does change when I fly like this? Airspeed? No, because I don't change the power setting and I do not climb or decend (apart from a bit less speed while having a higher bank angle, but that does not really matter). Groundspeed changes? Yes. Do I care? No. Groundspeed has nothing to do with the aerodynamics of my plane or helicopter.
When I do a rec for a landing spot, I should do a circle around it. Is there any difference then in a plank? No. I just bank more or less depending where the wind is pushing me, but I do not change airspeed if I do not climb or descend or change the power setting. Therefore you can not crash due to loss of airspeed while doing normal circles around a point, because the airspeed does not change when you do it correctly, only the bank angle.
Now, if you fly on a extremly windy day, you probably have to hurry turning while going downwind to keep the point on the ground in sight and bank angles will come close to aerobatic limits, but airspeed would still not change a bit.
... an now something completely different ... hopefully.