Fly-by-wire and gliders

On Friday, 31 October 2014 02:04:10 UTC+2, Ramy wrote:
While I am not looking forward for any automatic controls, I agree with the OP that FBW will significant improve performance. I believe the lost of performance due to inaccurate pilot input, un centered yaw string (heavy foot), non optimal flap position (I estimate I am flying in non optimal flap position maybe 30% of the time especially when doing a lot of transitions), flying too slow/too fast etc hurts performance more than the difference in glide performance between modern gliders.

Ramy

Yes and we have to remember that whole concept of conventional glider with tail has built-in-drag as elevator pushes the tail down all the time instead of giving only occasional control inputs. I bet there is several extra % of drag right there, as is in the large wetted area of long rear fuselage and rudder, which is only needed to counteract the yaw created by aileron drag. Flight controls have to be designed to have nice feel and harmony. Would there be more aerodynamically optimal geometries if this would be a non-issue? You could program any control feel you wish to joystick.

New wingprofiles (current are from nineties BTW, Ventus 2 & ASW 27 etc.) could be used with more narrow area of optimum angle-of-attack as FBW could nail it indefinetly while thermalling.

One could speculate with safety aspects as well. FBW would be easily programmed with unability to stall. Think about it, only coordinated turns, if you pull the stick while thermalling low, nose would go up until close to stalling angle of attack but not an inch more.

I believe hardware is coming cheaper and easily available as this is all stuff that UAVs use right now. You probably got most of the required sensors in your pocket right now. And I bet that at least some Akaflieg have studied this concept already.

Would we want FBW controlled glider? Did we want glider made from glassfibre instead of wood during 60s? Electrical varios during 70s? Or GPS in 90s? PW5? (No wait, no-one wanted that.)

THEY ALL RUINED THE SPORT when introduced, remember?

One thing to consider is what will happen when the FBW will fail from some reason and you end up with pilots who don't know how to fly manually as happened to AF447.

Ramy

On 10/31/2014 3:22 PM, Ramy wrote:
One thing to consider is what will happen when the FBW will fail from
some reason and you end up with pilots who don't know how to fly
manually as happened to AF447.

Ramy

Are you saying that simply pushing the "Return to Gliderport" button
might not always be an option?

Vaughn