I don't think we're disagreeing
I think you might need to rethink this. Seriously!
Kinetic energy is your friend and will take you a long way, you lose less by converting kinetic than you do from being at a speed from Vx to Vy than you currently believe.
When you're in the turn you're not making headway over the ground (you're inscribing an arc around a stationary point), but you're still losing height.
Because you're banked your sink rate will be measured against the circling polar curve for whatever bank angle you're at, rather than the 1g straight and level polar, so not only are you losing height without going anywhere, you're losing it faster than you would be if you were flying at best glide (or min sink for that matter)
When you come out of the turn, you need to be close enough to the upwind threshold of your runway to reach it from your current height at whatever glide angle you happen you get at your airspeed, wing loading and tailwind.
If your achievable glide angle from that point is steeper than the glide angle required to reach the upwind threshold, you simply will not and can not make it. Aerodynamic impossibility. Make another plan.
So in practical terms, you mustn't attempt the maneuver in the first place unless your aircraft's climb performance is good enough to provide for a climb angle significantly steeper than your achievable glide angle, especially if the runway is short (ie, the distance you need to cover to get back to it is higher)
If not, the video I am about to show you is a fake? You cant beat physics, no matter what you say!
No, I am not saying the video is fake. The video clearly features an aircraft which climbs better than it glides -- exactly what I said was required.
I note you talked about angles, most people do not equate angles so well.
Glider pilots, who are trained in turn back maneuvers and need to demonstrate competence in safely executing them, think in terms of angles a lot. It's how we judge a final glide from 20 miles out and know whether we can make it or whether we need to top-up with another couple of hundred feed in an enroute thermal. It's also the primary positional reference for every engine-off circuit ("What's the angle down to the aiming point?"). With practice it becomes second nature.
A GA aircraft without a functioning engine is a glider. When in Rome...
I've done hundreds of turn backs while teaching ab initio glider pilots. A keen appreciation of angles is how you decide right there on the spot whether to continue the turn back or proceed with an off-airport landing. It's important to get it right, because the top wire of the typical sheep-paddock fence is at approximately neck height for a glider pilot; pilots who misjudge approaches and land on the wrong side of the fence tend to get decapitated when they hit it during roll-out.
I have talked about IAS and we should keep it there. By the way best glide speed is a shallower angle than my best climb!
Then you, my friend, are flying an aircraft that is at least theoretically capable of the turn back maneuver.
As I said earlier, the average Cessna or Cub driver probably isn't, especially on a hot day with full fuel.
And since Cessnas tend to be a pretty common training platform, it isn't surprising that the instructors who teach in them warn against attempting turn backs: the aircraft they are most familiar with probably isn't even theoretically capable of successfully carrying it out.
But our RVs probably are. With appropriate training.
Someone mentioned about not unloading......what??
Do you guys never do engine failure training.....CHECK FORWARD!!!! And maintain airspeed, in the turn unloading is part of that. Training and practise.
Agreed -- unloading is required otherwise airspeed will decay very quickly.
Also remember that best glide speed in a 50 - 60 degree bank (min height loss turn) is higher than the straight and level 1g best glide speed. You'll need to be faster and steeper than you think to carry it out safely, which is one of the reasons why training is so important.
takeoff is simulated at my normal climb out speed, greater than Vy by about 10 knots, and at 500AGL we pull throttle say OHH Bother, about 3 times and into a 45 degree AOB turn, we would have crashed all right, into the fence at the far end!
You'll get back even higher (or, alternatively, be able to safely begin the maneuver from a lower height) if you bank at 60 instead of 45. Makes about a 50' difference in my -6, which is worth 10% of your starting height.
Takes a lot more attention to speed/attitude control and rudder coordination though. Most GA pilots are thoroughly unfamiliar with precise handling at a bank angle like that, and are more likely to (fatally) mess it up if they aren't adequately trained.
- mark