Sidestick control vs control yoke vs panel-mounted control wheel

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SVSUSteve

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Quick question (and I may end up making a formal poll out of this):
Among the members of this forum, what features would you prefer to see on the control column/center stick of a high performance aircraft?

-Autopilot disconnect
-Rudder/elevator/aileron trim
-Radio PTT
-VHF Comm 1/2 switching
-Strobe lights on/off
-TOGA setting

Other options:
-Flaps
-Landing gear
-Strobe light on/off
-Landing lights on/off
-Speed brakes/flight spoilers

Any other suggestions?
 

Aircar

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Just catching up on this thread -- the discussion has gone full circle and returned to the ergonomically best under seat pivot but duplicated to give either handed operation.

After you have muddled around with all sorts of possibilities you sometimes realize that you have 'invented' the conventional solution for probably the same reasons that it became conventional OR alternately you have come to understand the essence of the problem and now have a methodical way to generate and evaluate truly novel solutions -however it is the brain works we seem to go through this sort of process as a matter of course and only AFTER 'finding' the solution is it clear and we wonder why we couldn't see it all along. Paul Mac cready made a particular study of this phenomenon after noting it in his own work (he was dyslexic also which seems to put more emphasis on non verbal or written thinking )

Finding a GENERAL principle for addressing design issues would be of real help in ANY novel design task and benefit homebuilt (non formally trained or otherwise )designers --what IS "design" anyway ? --the engineering part is relatively well established and can be taught . The origin of the 'input' options is the undefined part.

I believe that a "matrix' approach can reduce the time and add some systematic process to generating 'candidate' options (eg control 'stick' possibilities, overall configurations etc) --this thread is a handy example .

going back to specifics (the LESS important case) --if you roll back to threads #28 and #44 you will find the "yoke on a stick" [in the form of the Victa Airtourer 'spade grip' --on a centreline stick in that case, and the Jabiru "Y" (also central but appearing in other aircraft even as a throw over dual control set up or 'rams horns' eg Concorde ) --also the description of the underseat steering on recumbents .

Formatting a matrix from the type of elevator action (wrist pivot, low pivot,sliding action or long arc in plan,overhead pivot ,other ) and the type of aileron action (wrist pivot,low pivot, overhead, other (eg parallelogram action) and then setting up a matrix for other interactions --trim on stick ,twist grip throttle,foot throttle [trikes] etc etc] you can create a 'mesh' of all possible combinations and then identify those that are not 'standard' or might not be 'thought of' and in doing so lead to other lines of thought .

end send cont,
 

Aircar

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There are a couple of "erratum' to take care of first from the thread --several times the term "anti servo tab" was used in talking about actuating controls indirectly --I think that "servo" tab is what is meant here since and anti servo tab opposes control deflection and adds to stickforces --they are useful for trimming and in that function work in 'reverse' .

I understand that the 707 was flown by servo tabs but never worked on them to be sure --and thanks to Matthew for posting that link to the aircraft manuals and drawings (when I was working for domestic airlines and they moved the maintenance base boxes of "obsolete" manuals were thrown out that would be a goldmine of technical information now --manuals for DC3 DC4 Convair 440 Friendship 707 727 etc etc and sales stuff for aircraft they didn't operate --more detailed cutaways are avialable from flight international vis their website ---studying these sorts of things can be of most value after wrestling with some design issue and then seeing how something (that wouldn't even be noticed beforehand) was solved (wing folding and control continuity for example )

I met a bloke one time who told me that his grand uncle (?) had 'invented' the now standard control stick used on aircraft but for the motor car and the first one is in the motor museum in England (Bristol I think ) --this story appears to be true based on ac series of articles in the Aeroplane (and later published as "the evolution of the front office" that went from the earliest airplanes like the Wrights two sticks and hip cradle to the Bleriot and all sorts of ideas --the 'stick' set up was push right to go right ,forward for more speed and back for less or brake (more like controlling a horse )

If the recumbent underseat pivot is 'analyzed' and the ergonomics relative to the elbow pivot you will find that the CENTRE pivot for "aileron" input is not right --the pivot for roll should be under the thigh (as previously posted) --this gives no rise and fall for aileron as will happen with a cntre pivot --and you can easily add another -centre,(between legs) stick with very little additional so the 'solution' for the most ideal control set up might well be THREE sticks --covers all bases (and is the simplest also for a side by side two seater ...) I think John McGinnis has arrived at a similar geometry with his "side stick" (but not wrist action if I interpret his photo correctly --or just for elevator)

The positioning of controls and standardized shape of knobs (to reflect the function --a circular knob for wheel retract a triangluar one for flaps etc ) and colour coding is already conventionalized to minimize the confusion issue -- it is helped ny little pictograms next to the knob as used on German gliders for international recognition (a little tap for water ballast etc) --some gliders are so supine thast you cannot easily see the controls --the Edelweiss was such that the pilot had to learn the minor controls by feel (probably not a bad thing anyway if you ever lose cockpit lighting at night or don't have any ) One small oversight in the Partenavia twin resulted in as huge outcome that resulted in training flight being banned, calls to shut down the secondary airport (Essendon,Melbourne ) a massive series of lawsuits right back to the italian "FAA" etc etc --the trim button on top of the control yoke could be inadvertently depressed and was such that the other pilot (instructor) could not overide it and the manual trim was inadequate, stick forces beyond pilot capability arose and a plunge into houses resulted with an entire family killed . Subsequent investigation determined the chain of causes and needed re certification changing the trim limits and anti servo tab gearing, manual trim wheel increase and re 'badging' ,an overide on the yoke electric trim,clutch etc etc .

Look forward to seeing SVSUSteve's design and the design rationale that eventuates. and also Hot Wings recumbent design --I have 'flown' about a dozen different recumbents with all sorts of set ups including underseat and wince at looking at some where a 'wipe out' on gravel would result in grinding away of the knuckles and do real damage --with my lat iteration of the recumbent I went to the 'under thigh pivot ' as much as anything to avoid this danger and just found that it 'fell into place' ergomonically --and then understood why.
 

Hot Wings

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The map lights are a nice touch but do you really want light bouncing off the documents from the front side? I much prefer light directed from behind - less glare.

Second observation, do you have the elevator and rudder trim switches labeled backwards, or am I misinterpreting the direction your rocker switches work? The aileron trim is orientated as I would find natural.
 

SVSUSteve

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The map lights are a nice touch but do you really want light bouncing off the documents from the front side? I much prefer light directed from behind - less glare.
Red lights so you don't ruin your night vision.

Second observation, do you have the elevator and rudder trim switches labeled backwards, or am I misinterpreting the direction your rocker switches work?
No, they are oriented the way I want them. The elevator trim works in an up or down motion and the rudder is oriented to work side to side.
 

Hot Wings

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No, they are oriented the way I want them. The elevator trim works in an up or down motion and the rudder is oriented to work side to side.

That's the way I would have expected. Just looked like the elevator was L/R and the rudder U/D.
 

fly2kads

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It looks like your buttons for Push to Talk and Autopilot Disconnect are the same size, shape, and color. One of the Cessnas I used to rent was equipped like that. Because I only flew that plane only once in a while, I pushed the wrong **** button every flight. At least once. Fortunately, there was no significant consequence for getting it wrong, but it was rather annoying. I think if I flew that particular aircraft more regularly, I could have trained myself to get it straightened out. For occasional use, though, it bugged the crap out of me. Since this will be your aircraft, it may not be as much of a problem.
 

SVSUSteve

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It looks like your buttons for Push to Talk and Autopilot Disconnect are the same size, shape, and color. One of the Cessnas I used to rent was equipped like that. Because I only flew that plane only once in a while, I pushed the wrong **** button every flight. At least once. Fortunately, there was no significant consequence for getting it wrong, but it was rather annoying. I think if I flew that particular aircraft more regularly, I could have trained myself to get it straightened out. For occasional use, though, it bugged the crap out of me. Since this will be your aircraft, it may not be as much of a problem.
Actually, I found (after I drew that) a blue button to use for the PTT as opposed to the red for the disconnect.
 

Aircar

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I had thought the topic was to do with the biomechanics of the actual control system (connection between hands and usually feet and the control surfaces ,wheels,flaps etc rather than the disposition of switches on a control yoke (which I take it is the U shaped part in your sketch ) ... hasn't the US air force published a standardized set up with the pistol grip and finger/thumb functions decided? --ie "chinaman's hat' on top for roll and for aft trim , gun button, bomb release etc ? --the set up on motorbike handlebars is another example that is more intuitive than most aircraft --throttle and brakes on one lever ,thumb switches for lights, start,clutch, gear change etc

For roadability these other functions need to be included as well ( the 'switch over' from ground controls to flying has been an issue and the same sort of thing is there with switching for differential braking or nose wheel to rudder) dumping lift rapidly on touch down should be doable without looking for a lever somewhere as well . Bicycle type brake levers could be incorporated for differential braking and be intuitive as well . (for an actual flying bicycle the effect of pedalling induces hand motions that better not affect the flight controls . Eliminating some switches by combining functions in a grip --for example a 'squeeze' switch could engage autopilot as soon as control was released and vice versa (with a red/green light to show which mode was current )--that confusion between lights and auto pilot could be lethal. (and shouldn't everything be doable from either hand if you are required to operate other controls with the other hand ? flaps,gear,maybe airbrakes for a few. Are you having dual controls as well ?
 

autoreply

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Quick question (and I may end up making a formal poll out of this):
Among the members of this forum, what features would you prefer to see on the control column/center stick of a high performance aircraft?

-Autopilot disconnect
-Rudder/elevator/aileron trim
-Radio PTT
-VHF Comm 1/2 switching
-Strobe lights on/off
-TOGA setting

Other options:
-Flaps
-Landing gear
-Strobe light on/off
-Landing lights on/off
-Speed brakes/flight spoilers

Any other suggestions?
I'd much rather go for a HOTAS approach. Put all the landing/ take off/manouvring switches on the throttle (flaps, landing gear, speed brakes) and only have the essential/frequent switches on the stick (PTT, Comm switching, trim, AP. Strobes and lights are almost irrelevant, switched a max of 2 times a flight and should be somewhere far away from primary controls.
 

SVSUSteve

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Strobes and lights are almost irrelevant, switched a max of 2 times a flight and should be somewhere far away from primary controls.
Spoken like someone who doesn't fly into and out of clouds at night very often. Strobes in clouds at night can rapidly induce vertigo in a lot of folks so the ability to kick them off quickly without having to look up or around for the switch is a handy feature.

I will probably move the TOGA to the throttle as you suggested. The flaps and ground spoilers controls (the primary ones) are on the throttle quadrant anyhow.

hasn't the US air force published a standardized set up with the pistol grip and finger/thumb functions decided
Not that I have been able to find a formal publication on.


That said, I prefer a "dual" switch for each of the trim functions to minimize the chance of inadvertent activation or runaway.
 

SVSUSteve

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Are you having dual controls as well ?
Yes, this will be an effectively dual pilot aircraft.

Eliminating some switches by combining functions in a grip --for example a 'squeeze' switch could engage autopilot as soon as control was released and vice versa
Not so much unless you're just including a basic wings leveler like was fitted on some of the early Mooneys. The three-axis autopilot going on this design is probably not readily modifiable to be kicked on quite so easily.

that confusion between lights and auto pilot could be lethal.
It's a little more intuitive than that. Also having an audible alarm that says "AUTOPILOT OFF" will be incorporated whenever the disconnect button is pushed would make it pretty obvious. Another option is to have a cap over the autopilot button that must be flipped up to activate it.

shouldn't everything be doable from either hand if you are required to operate other controls with the other hand
Ideally, yes, but at the same time, it's almost impossible to achieve without utilizing a sidestick or "center stick" which I want to stay away from for the reasons previously stated. I could conceivably put them all on the side of the control opposite the throttle quadrant....
 

Rick McWilliams

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Electrical connections to the buttons on the stick or yoke are a source of problems. I think that every aircraft that I have owned has had some problems in that area. I have an intermitant ground issue now on one.

I particularly liked the push to transmit button on the throttle of my Christen Eagle II.
 

Topaz

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Actually, I found (after I drew that) a blue button to use for the PTT as opposed to the red for the disconnect.
That presumes you look down at the button before actuating it. Might be nice to have some tactile difference as well, so that in a high-stress situation you don't have to look. Might be as simple as a bump or bead of something on one of the switch faces.
 

TinBender

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That presumes you look down at the button before actuating it. Might be nice to have some tactile difference as well, so that in a high-stress situation you don't have to look. Might be as simple as a bump or bead of something on one of the switch faces.
I really like the Legacy C-130 setup. You key the radio by pulling the funny shaped trigger, while pushing the trigger activates the interphone. The autopilot button has a ring around it so it cannon be tripped accidentally, but is very easy to find. The elevator trim is exactly where it needs to be. The go-around button is top thumb button. The other is a sync button, but could be used for something else. All these switches require a fair amount of pressure to activate, and *Click* nicely, letting you know they've been pushed. Elevator trim requires both switches to activate, and will stop when the other pilot presses a contrary position. The engine controls are in between the pilots and the buttons on the yoke are on the outboard handle.
yoke buttons.png

The elevator, aileron and rudder trim are found right behind the center engine quadrant. Since there is no manual connection to the elevator tabs, there is an emergency elevator control switch. This is a very intuitive setup. the ELE and AIL are on a toggle like a stick, and the rudder trim is ls waggled back and forth on a pivot, like the tail of the plane. It's an idea. Cheers, Jamie
trim.png
 

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PredragVasic

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I know this discussion took a deep dive into the details of side stick versus centre stick, but I would like to hear more about the reasons for so resoundingly dismissing the yoke as the control device. With apparently the biggest player in the commercial market sticking with the yoke (Boeing), in addition to many other smaller players, (Gulfstream, Cessna, Pilatus, Piper, Learjet, Embraer, others), it seems that the professionals don't really have such strong resentment. Even Airbus had them before introducing fly-by-wire and the side stick.

I admit I don't have nearly as many hours in the cockpit as most of veteran members here, but while centre stick was fun (felt like a fighter pilot), yoke made it easier to get in and out, put down the map/clipboard/iPad in the lap and move around the seat without hitting the stick.

Building it for our own homebuilts, the mechanics are a bit more involved (as someone mentioned, a couple of universal joints would be needed to translate the longitudinal movements of the yoke axis into the arc movement of the stick, while translating the rotational movement of the axis to the sideways swing of the stick), but all is still easily doable for a builder with standard skill and tools.

Virtually all of the plans / kits out there propose the centre stick, as it is the most elegant, robust, direct, frictionless and simple engineering solution. But I'm sure there are people who prefer a yoke. Am I to understand that they don't really frequent these forums?
 

Richard Schubert

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The forum is populated with better mousetrap types. I am slightly surprised that there hasn't been a thread on the pros and cons of control helmets.
 

cluttonfred

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Personally, I am not at all averse to a yoke control and I think they can absolutely work for a homebuilt. As a general rule, however, yoke control *systems* seem to weigh more than a simple joystick control *systems* and I think that is why we don't see them more often in homebuilts. Still, they have been used in some pretty succesful light aircraft (Aeronca Chief, Taylorcraft, etc.) that were certainly competitive in their day, so I don't see why they wouldn't work today.

Here's another twist...the late Emilien Croses designed several Mignet-type tandem-wing designs with two-axis control using an interesting bottom hinged control yoke that is, I think, I little easier and simpler than the traditional sliding push-pull type. Rotating the yoke provides roll control (or in the case of a Mignet type, yaw control) and the pushrod through the center of the tubular hub actuates the pitch control. Here are pics from a microlight Criquet L that I almost bought several years ago as well as another from the big seven-passenger Paras Cargo by Croses.

criquet l.jpgparas cargo.jpeg
 
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