Yoke vs. Stick

[Zio Nick]

Hi all,

Yesterday I was working at the flight controls of my company's simulator, for some technical reasons we had to disconnect the installed yoke and replace it temporarily with a side stick.
We evaluated the skills required to fly the simulator with the stick instead of the yoke and after solving some issues due to the different effect of gain between yoke and stick (which generated noticeable PIO) we gave controls to our Chief TP for him to express his opinion. Myself, the TP and the othe FTE all expressed the same opinion: controlling the a/c via the stick required much more attention and carefulness than by the yoke, mainly due to the coupling of front and side movements of the stick.
Of course I also personally tried a number of different calibrations, but indeed it was always much easier by using the yoke to decouple forw/aft displacements from right/left ones.
Of course I know that 99.9% of aerobatic a/c which are performing high precision manoeuvres are controlled by stick, but my personal impression is that the correct use of the stick requires more training compared to yokes.
I would like to know if you ever faced this issue and if you have different opinions. Any thoughts welcome!

[Genghis the Engineer]

I've significant time with both, including one type, and one research sim that were fitted with both.

In my opinion, IF the FCMC and stick force gradients are similar, and any sidestick arrangement provides an adequate armrest arrangement behind it, workloads are similar for similar tasks.

However, those things aren't always the same - sticks tend to usually have smaller deadbands, be mechanised with lower stick force gradients and tend to have different geometries. So, it's very hard to compare apples-with-apples when comparing sticks with yokes.

But to say that a stick creates greater workload for similar tasks than a yoke, in my opinion, overly simplifies things. In an airliner, for typical airliner manoeuvring tasks, comparing a typical airline yoke to a short low-force sidestick, quite possibly - but that's comparing apples with oranges.

G

[Cobalt]

From a simple pilot's perspective - I have flown Robin, DA40, DA42 (classic stick), Columbia 400 (sidestick) and SR22 (Side-Yoke).

I never found the transition hard, in fact the Columbia sidestick was a delight - but if I remember correctly, the Columbia side stick forward/aft direction is slightly angled to align with your arm movement, not the aircraft axis. I might be mistaken, though - Genghis, do you know?

The Cirrus thingy is not angled, and it needs a slight breakout force to initiate a roll which I personally found awkward - now that I read your experience that might be to prevent inadvertent roll inputs when pulling/pushing.

[John Farley]

In aircraft the whole business of sidestick versus yoke from a pure handling qualities standpoint is a non issue.

Your post sugests the side stick used in your sim was unservicable or unsuitable in its characteristics.

[Cobalt]

Nahh - side sticks are fantastic. Best of both worlds - free lap, free view of panel.

[Genghis the Engineer]

I never found the transition hard, in fact the Columbia sidestick was a delight - but if I remember correctly, the Columbia side stick forward/aft direction is slightly angled to align with your arm movement, not the aircraft axis. I might be mistaken, though - Genghis, do you know

No idea, never been near a Columbia. However, I've certainly flown two other types (the Shadow and the SkyArrow) with a cranked inwards sidestick. Both I recall it being vital to visually check that the ailerons are neutral at the start of the take-off run.

G

[Pilot DAR]

I have one of each. I like the stick, but I reluctantly concede that the control wheel has some benefits, depending upon the control forces. Pitch is not really an issue, but roll can be.

If the aileron forces are light, a stick is crisp and a delight, and control wheel not really beneficial. But, if aileron forces are high, the stick can be very unpleasant in gusty turbulence. My Teal is stick, and has very heavy ailerons. They are so, as they are designed so you can pick a heavy wing out of the water at low speed, and this works. However, it makes all the rest of the flying not so nice, a lot of muscle required, in an awkward direction for your arm. The Lake amphibian is extremely similar to the Teal in regard of ailerons (same designer, same operating environment). The Lake, however has a control wheel instead of a stick. You don't notice the heavy roll control.

It can be noticed when the forces required for flight in turbulence are not harmonized between roll and pitch - much more roll force required than pitch in some cases. This can lead to PIO, if you are applying control by feel, when the feel in roll is quite different than in pitch.

However, when planing on the water, precise pitch and roll attitude is important, and in this condition, the controls are nicely harmonized, though you're not displacing them much. you can "stir the pot" and the plane follows nicely, about like a helicopter - quick and precise. This is not so easy in the Lake, and not as natural.

I opine that that the feeling of "heavy" in roll with a stick is because to move the stick in roll, your arm has only one motion, which is not really a normal one, unless you're very used to plying through dense brush a lot. Whereas, with the control wheel, you have a lifting motion of your arm, combined with a rolling motion of your wrist, where you do have a fair amount of strength. You can get greater leverage with a control wheel. Indeed, when I was trained on the DC-3, it was specifically pointed out that the control wheel goes all the way around - right upside down, through to right upside down. You have to remind yourself that this amount of control is available, 'cause it's not natural! I suppose that Douglas back in the day used this to maximize control effort verses effect.

The AS350 helicopter is very light, with hydraulic controls. You quickly learn to rest your wrist on your leg, and use only a thumb and forefinger to fly, or over control is certain. However, the MD500, with manual controls requires muscle. but offers amazing natural feel while flying.

I suppose the the control wheel suggests that you can get both hands on it, to get full control in difficult circumstances. I have a few times had to do this, and certainly would not be here if the plane had a stick. While right seat PNF in a Piper Cheyenne, and just airborne (night, heavy snow, northern Ontario runway) the PF said "help me fly". What?! 'Turns out that we had one empty tip tank, and one full one - 400 pound fuel imbalance at the tip - fueling error. Yup, we needed the leverage of the control wheel.

So, it depends upon the aircraft type and nature of flying, each arrangement has it's merit, as long as it's designed in where it is needed.

[Zio Nick]

Gents, thanks a lot for sharing your opinions.

Let me say that my remark was mainly addressed to the human factor. Under the hypotheses to keep constant all the a/c characteristics but the human interface of controls, I noticed that my pilots tend to easily decouple for/aft movements from left/right when they use the yoke, while during the first minutes of flight with the stick they tend to combine some of these movements.
After a short practise they all tend to achieve the same decoupled results, but depending on the habits and training the adaptation can vary significantly.

When I was in the air force one of the typical mistakes made by student pilots, when trying to enter a spin with a stick controlled a/c, was to pull the control not completely straight to their belly, but also adding some right or left inputs, depending on which hand they were using.