Is the stick force affected by speed in the real A10?

[EAF51_Jimmi]

I imagine that Stability Augmentation System and hydraulics help removing the strain from the pilot, but I wonder if the stick force change anyway as the speed changes. I heard that a10 is still flown by the seat of your pants, but I wonder how much hydraulics masks this.

I'm asking this because coming from Warbirds world I normally use a DIY FORCE FEEDBACK.  A VKB gunfighter with extension that by DCS bios Arduino and a motor by a pulley and a rubber band stiffen and relax the stick force according to speed. I love the feeling for warbirds and a10 too but I wonder if it's good to simulate the a10 handling. 

[jaylw314]

I don't believe there is much 'feel' from aerodynamic loads based on what I've read.  The flight manual mentions that stick forces and positions for a given g load are essentially linear throughout the flight envelope, but that's about all the detail I've heard about, so I might be interpreting that wrong

FYI the trim tabs function as servo tabs in normal flight (not MRFCS), so they also help to reduce aerodynamic loads proportionally.  There is actually an 'artificial feel' mechanism that provides spring force to the stick.  The trim control just adjusts its center point under normal conditions.  This suggests that the expected aerodynamic loads are almost entirely cancelled out by the hydraulic and servo tab systems, but, again, that's just a guess on my part.

AFAIK, the pitch SAS has limited authority so it probably doesn't contribute much to big control forces.

Edited March 8, 2023 by jaylw314

[ASAP]

1 hour ago, jaylw314 said:

I don't believe there is much 'feel' from aerodynamic loads based on what I've read.  The flight manual mentions that stick forces and positions for a given g load are essentially linear throughout the flight envelope [...]  There is actually an 'artificial feel' mechanism that provides spring force to the stick. [...] aerodynamic loads are almost entirely cancelled out by the hydraulic and servo tab systems.

AFAIK, the pitch SAS has limited authority so it probably doesn't contribute much to big control forces.

That's all correct as far as I'm aware. Going faster wont make you have to pull harder on the stick. The thing that changes with speed is how much G's you'll get for a given stick throw, and how much stick throw you have before you get into the steady and chopped tones, which is telling you where you are in relation to the edges of the flight envelope. If you go fast you can pull more before you hit peak performance or an accelerated stall (which is what those tones are telling you). Using those tones is absolutely critical to flying the aircraft properly from everything I've heard, and a lot of the time the steady tone is a very small region in terms of stick position. That's the part that requires finesse and some of the flying by the seat of the pants feeling that people talk about. 

side note: The term flying by the seat of your pants refers to a lot of other airplanes tendencies to buffet and shake as its being maneuvered aggressively. Pilots will "pull until they get a light tickle" over the wings vs "elephants on the wings" indicating an accelerated stall.  The shape of the A-10 wing doesn't lend itself to causing that buffet so the tones are used to relay essentially the same info to the pilot. 

[jaylw314]

4 hours ago, ASAP said:

That's all correct as far as I'm aware. Going faster wont make you have to pull harder on the stick. The thing that changes with speed is how much G's you'll get for a given stick throw, and how much stick throw you have before you get into the steady and chopped tones, which is telling you where you are in relation to the edges of the flight envelope. If you go fast you can pull more before you hit peak performance or an accelerated stall (which is what those tones are telling you). Using those tones is absolutely critical to flying the aircraft properly from everything I've heard, and a lot of the time the steady tone is a very small region in terms of stick position. That's the part that requires finesse and some of the flying by the seat of the pants feeling that people talk about. 

side note: The term flying by the seat of your pants refers to a lot of other airplanes tendencies to buffet and shake as its being maneuvered aggressively. Pilots will "pull until they get a light tickle" over the wings vs "elephants on the wings" indicating an accelerated stall.  The shape of the A-10 wing doesn't lend itself to causing that buffet so the tones are used to relay essentially the same info to the pilot. 

Not to be pedantic (too late!), but flying by the "seat of your pants" originally referred to navigation, as in Douglas 'Wrong Way' Corrigan  Nowadays, of course, we can use it to refer to whatever we want.  Most commonly, I hear it in reference to using the proper amount of rudder to coordinate turns, as in using buttock-sensing instead of watching the ball  

[ASAP]

4 hours ago, jaylw314 said:

Not to be pedantic (too late!), but flying by the "seat of your pants" originally referred to navigation, as in Douglas 'Wrong Way' Corrigan  Nowadays, of course, we can use it to refer to whatever we want.  Most commonly, I hear it in reference to using the proper amount of rudder to coordinate turns, as in using buttock-sensing instead of watching the ball  

So pedantic! (JK) I think we agree fundamentally that it means you feel what the airplane is doing vs reading it off an instrument (great way to die when flying in instrument conditions BTW). I was offering just one example of how that would present itself in a modern military jet, and how the A-10 was different WRT stick throw/airspeed which was the original point of the post.

[EAF51_Jimmi]

Ty all for the replay!

19 hours ago, ASAP said:

The thing that changes with speed is how much G's you'll get for a given stick throw, and how much stick throw you have before you get into the steady and chopped tones, which is telling you where you are in relation to the edges of the flight envelope. If you go fast you can pull more before you hit peak performance or an accelerated stall (which is what those tones are telling you). Using those tones is absolutely critical to flying the aircraft properly from everything I've heard, and a lot of the time the steady tone is a very small region in terms of stick position. That's the part that requires finesse and some of the flying by the seat of the pants feeling that people talk about. 

Good point and good info. Will listen more to the tone!

In the end I think I will keep the speed force feeling on the stick anyway, it's so much fun flying with it and compensate a little for the lack of G force!

[jaylw314]

2 hours ago, EAF51_Jimmi said:

Ty all for the replay!

Good point and good info. Will listen more to the tone!

In the end I think I will keep the speed force feeling on the stick anyway, it's so much fun flying with it and compensate a little for the lack of G force!

The A-10 flies pretty traditionally anyway, so that's fine.  I'm not sure about the design choice in the A-10 myself, it seems like ramping up the stick force with airspeed even a little would make sense so you had tactile awareness of your airspeed, but I'm guessing it was just simpler that way.

 

13 hours ago, ASAP said:

So pedantic! (JK) I think we agree fundamentally that it means you feel what the airplane is doing vs reading it off an instrument (great way to die when flying in instrument conditions BTW). I was offering just one example of how that would present itself in a modern military jet, and how the A-10 was different WRT stick throw/airspeed which was the original point of the post.

LOL, if you haven't heard the story of 'Wrong Way' Corrigan, you should, it's hilariously awesome   the 'seat of the pants' came from a news article about his (in)famous flight