Bad cockpit design?

Having gathered a few DCS planes, something strikes me as a little odd. It's the positioning of the stick in combat planes.

In the old days, the stick was placed between the pilot's legs, with the throttle by/on the left armrest. I guess this made sense - the right hand on the stick, the left hand on the throttle. The stick needs more precise movement, and most people are right-handed. In extreme situations, both hands can be brought on the stick in order to apply extra force.

But with fly-by-wire (e.g. M2000C, A-10C, F15), why is the stick still often between the pilot's legs? Surely this leads to the body being twisted/offcentre for extended durations. In an office situation that would be less than ideal - I can only imagine what it's like under high-G. The F16 has the stick in what I would think is a much better position.

I've never flown any of these planes in real life; do combat pilots suffer more than most people from RSI? :)

Not for helicopters it feels natural for me. :)

I always thought side stick setups are awful and unnatural. It's much more comfortable and relaxed to hold your arm close to your center mass instead of leaning it off to the side. In my opinion it's also significantly easier to precisely move the stick this way. Having the stick perfectly aligned with the movement axes is also nice.

Besides RSI due to this is nothing compared to what their neck experiences under sever 9G ACM exposure. :D

Having gathered a few DCS planes, something strikes me as a little odd. It's the positioning of the stick in combat planes.

 

In the old days, the stick was placed between the pilot's legs, with the throttle by/on the left armrest. I guess this made sense - the right hand on the stick, the left hand on the throttle. The stick needs more precise movement, and most people are right-handed. In extreme situations, both hands can be brought on the stick in order to apply extra force.

 

But with fly-by-wire (e.g. M2000C, A-10C, F15), why is the stick still often between the pilot's legs? Surely this leads to the body being twisted/offcentre for extended durations. In an office situation that would be less than ideal - I can only imagine what it's like under high-G. The F16 has the stick in what I would think is a much better position.

 

I've never flown any of these planes in real life; do combat pilots suffer more than most people from RSI? :)

There are two considerations here when talking about stick position.

1. A center stick allows more "throw", which allows more precision. Side mounted sticks rely on force sensing instead of displacement.
   
2. Even though the F/A-18 is as much a FBW aircraft as the F-16, as a carrier jet it will always be center-mounted.
   

First, there is a big difference between hydraulically controlled aircraft with stability augmentation (A-10, F-15) and fully fly-by-wire aircraft like the F-16 and F/A-18. A center-mounted stick will always give you more throw because the length of the shaft extends from the floor (even if the pivot point is halfway up). This amount of throw is necessary for precision control of a conventional hydraulic system. In contrast, a full FBW system receives inputs from the pilot, then interprets the inputs as intent rather than direct control surface movement. Since there's no direct hydraulic linkage, a stick can be side-mounted and set to detect applied force rather than physical deflection. This is how the F-16 works. A side mounted stick will never have the "throw," and therefore never have the precision of a center mounted stick in controlling a conventional hydraulic system. Of couse, you can still mount sticks conventionally with FBW aircraft, its just that FBW provides the option of the side-stick.

So the next question: if you can use pressure sensing to control a FBW aircraft, and modern aircraft are all FBW, why don't we see more side mounted sticks? I don't know the global answer to that, but I can answer for the US Navy and Marine Corps. Any carrier aircraft designed to operate out of range of land bases (i.e. "blue water" operations) will have a center mounted stick (also used to require 2 engines, but this is changing with the F-35, a change with which I disagree). This is because any plane operating over "blue water" must be able to make it back to the carrier for the aircrew to have a reasonable chance of survival. Look at it this way: if you lose your engine or break your right arm in the F-16, you're likely to be ejecting over land. This may not be a garden party, but even without food or water your life expectancy is measured in days. Conversely, eject over the ocean (especially in cold water) and your lifespan is measured in minutes, so if you break your right arm you need your left hand to control the aircraft at least until you get in range of the battle group and the rescue helo.

It's probably more of a design practice, like the Boeing vs Airbus thing, without a clear winner. A sidestick allows you to design more ergonomic cokcpit, but the centre stick is actually quite comfortable. You can also use it with your left hand if needed.

Your body is not twisted when using a centre stick, the stick itself is twisted.

Honestly from all the IRL jets I've sat in the Viper is by far the most comfortable once its set up correctly... But pretty much all F-16 pilots I know (a few) suffer from neck and back issues due to the angle of seat.

All setups have Pros and Cons I guess..

Very interesting and valid points, thanks.

Working mostly at a desk, I don't have to worry about broken arms etc when I think about ergonomics.

The fact that the Viper also has a heavily reclined seat to counter Hi-G loadings may have led the designers to opt for a side stick perhaps?

It would mean it could be positioned further aft, giving an ergonomically better configuration whereas with your shoulders further back, a centre stick may have needed pilots with arms like gorillas.

There are two considerations here when talking about stick position.

1. A center stick allows more "throw", which allows more precision. Side mounted sticks rely on force sensing instead of displacement.
   
2. Even though the F/A-18 is as much a FBW aircraft as the F-16, as a carrier jet it will always be center-mounted.
   

 

First, there is a big difference between hydraulically controlled aircraft with stability augmentation (A-10, F-15) and fully fly-by-wire aircraft like the F-16 and F/A-18. A center-mounted stick will always give you more throw because the length of the shaft extends from the floor (even if the pivot point is halfway up). This amount of throw is necessary for precision control of a conventional hydraulic system. In contrast, a full FBW system receives inputs from the pilot, then interprets the inputs as intent rather than direct control surface movement. Since there's no direct hydraulic linkage, a stick can be side-mounted and set to detect applied force rather than physical deflection. This is how the F-16 works. A side mounted stick will never have the "throw," and therefore never have the precision of a center mounted stick in controlling a conventional hydraulic system. Of couse, you can still mount sticks conventionally with FBW aircraft, its just that FBW provides the option of the side-stick.

 

So the next question: if you can use pressure sensing to control a FBW aircraft, and modern aircraft are all FBW, why don't we see more side mounted sticks? I don't know the global answer to that, but I can answer for the US Navy and Marine Corps. Any carrier aircraft designed to operate out of range of land bases (i.e. "blue water" operations) will have a center mounted stick (also used to require 2 engines, but this is changing with the F-35, a change with which I disagree). This is because any plane operating over "blue water" must be able to make it back to the carrier for the aircrew to have a reasonable chance of survival. Look at it this way: if you lose your engine or break your right arm in the F-16, you're likely to be ejecting over land. This may not be a garden party, but even without food or water your life expectancy is measured in days. Conversely, eject over the ocean (especially in cold water) and your lifespan is measured in minutes, so if you break your right arm you need your left hand to control the aircraft at least until you get in range of the battle group and the rescue helo.

I'm struggling to think of a scenario where the pilot's aircraft would have sustained a hit that would have broken his arm and would not be instructed to ditch rather than try and put down on the carrier.

I'm struggling to think of a scenario where the pilot's aircraft would have sustained a hit that would have broken his arm and would not be instructed to ditch rather than try and put down on the carrier.

How about a bird strike? You don't need to come up with a situation to realize that such a situation may arise. It's just good design redundancy.

I never said that the pilot would put down on the carrier; certainly not with only one arm and nothing controlling the throttle. However, ditching or ejecting close to the battle group greatly enhances chances of survival, both in terms of minimal exposure time and the reduced search area for recovering the aircrew.

How about a bird strike? You don't need to come up with a situation to realize that such a situation may arise. It's just good design redundancy.

 

I never said that the pilot would put down on the carrier; certainly not with only one arm and nothing controlling the throttle. However, ditching or ejecting close to the battle group greatly enhances chances of survival, both in terms of minimal exposure time and the reduced search area for recovering the aircrew.

Thing is, F-35 has both single engine and a sidestick. Times change.

Flown well over 10000hrs in yoke, stick, sidestick, non FBW and FBW equipped planes. You get used to each version very rapidly. No real preference here.

Each one can be controlled very precisely.

I concur. While I'm not a real pilot, I have a yoke, center mounted stick, left hand stick (Airbus style) and also briefly used a force sensing stick. All of them can be used to fly an airplane with enough precision, with an exception that the force sensing stick is generally terrible for aircraft that require constant stick displacement to fly straight (helos, props).

why is the stick still often between the pilot's legs? Surely this leads to the body being twisted/offcentre for extended durations.

Actually it's the opposite... without arm supports for the side stick pilot would not be able fly as well (endurance) as with center stick. It is less ergonomic. Center stick also has on the plus side that it gives you better visual cue besides being able to use it with both hands.

That being said, any negative side can be overcome by training, so in the end if the pilot is well used, there are no noticable penalties in pilot's performance in either way.

Thing is, F-35 has both single engine and a sidestick. Times change.

I haven't seen the F-35C (Navy) cockpit, but this is the case with the F-35B (the USMC V/STOL variant). Not as big a deal for Marines operating off gator boats within range of the beach. If the F-35C has a right-mounted stick, it's another design compromise I disagree with (I already said I don't like the single engine). It could be a matter of politics dictating the compromise to keep cost overruns in check, but even though things change over time, Global Warming hasn't raised the ocean temperatures enough to improve survivability following an overwater ejection.

...Global Warming hasn't raised the ocean temperatures enough to improve survivability following an overwater ejection.

:megalol::megalol: :thumbup:

It's probably more of a design practice, like the Boeing vs Airbus thing, without a clear winner. A sidestick allows you to design more ergonomic cokcpit, but the centre stick is actually quite comfortable. You can also use it with your left hand if needed.

 

Your body is not twisted when using a centre stick, the stick itself is twisted.

I would say from a safety standpoint the airbus style has proven more dangerous and less intuitive (no feedback to what the other pilot is doing).

But that is not really pertinent to this discussion.

Personally side sticks just look annoying and uncomfortable. IMHO

I would say from a safety standpoint the airbus style has proven more dangerous and less intuitive

proven by what?

proven by what?

Not proven, just an opinion.

Still, a great discussion, please continue, following w/ interest :thumbup:

proven by what?

There was an airbus (Air france i believe) that the co-pilot was making a large nose up input and the pilot was making a large nose down input (or the other way around) without knowing what the other one was doing and since the FCS takes the average of the inputs and they ended up stalling and crashing IIRC. I can't find the crash right now, but i will keep looking and post it if i find it.

And of course it's just my opinion, and the airbus side stick vs yoke is kind of OT anyway.

P.S.

Found it:

https://en.wikipedia.org/wiki/Air_France_Flight_447#Sidestick_control_issue

Looks like there were other factors that caused initial error, but were exacerbated by the control issue.

i think you are confusing unrelated issues. lack of feedback has nothing to do with stick location.

simmers enjoy ffb sticks that can be mounted on the side just as easily as in the center, and had airbus so chosen to, they could link sidesticks to give synched haptic feedback.

i think you are confusing unrelated issues. lack of feedback has nothing to do with stick location.

simmers enjoy ffb sticks that can be mounted on the side just as easily as in the center, and had airbus so chosen to, they could link sidesticks to give synched haptic feedback.

Like i said, i was talking specifically about airbus vs. boeing and that it was off topic.

Apart from that, I personally have always thought the center stick made more sense and was more intuitive/versatile.

And that doesn't mean i am completely against side sticks or anything, do what ever gives you the most comfort and control.

How about a bird strike? You don't need to come up with a situation to realize that such a situation may arise. It's just good design redundancy.

 

I never said that the pilot would put down on the carrier; certainly not with only one arm and nothing controlling the throttle. However, ditching or ejecting close to the battle group greatly enhances chances of survival, both in terms of minimal exposure time and the reduced search area for recovering the aircrew.

And why exactly can a pilot with a side stick not limp home to ditch by a carrier? I fly side stick style and it's much more comfortable and not particularly hard to 'fly' using the off hand with the sort of accuracy needed simply to get near a carrier group to bail. Landing on a carrier wouldn't be an option if you flew center stick anyway so I'm not really seeing your argument from a redundancy standpoint.

That's not a flaw. If you want to have control you simply push the takeover button on the sidestick and there will be a visual alert in front of both pilots and an aural alert sounds that you have taken over control.

But in the confusion of this incident the captain did not take over and was not aware of what the other pilot was doing. It is impossible to not know where the controls actually are in a connected system.

I don't know how something that contributed (not caused, contributed) to an incident which ended in the death of 228 people can not be seen as a flaw.

And again this is not related to cockpit design of single seat combat aircraft.

As to a side stick being harder to use with a bad right arm, I think it would definitely be harder to be reaching all the way across the cockpit between the throttle and the stick while dealing with emergencies and pain.

Its about making things easier not just possible.

Very interesting discussion by the way.

About the AF447, that's just speculation, as the crew has entered stall condition that they failed to recognize, and there were many more things going wrong in there.

if the plane is not fly by wire then the stick is placed in the centre of the airframe to make all the control runs the same length and to reduce complexity. for the controls to have the same weight they must be balanced. and that's a lot of wire to balance.

the pilot is then placed where he can best reach them.

so its normally between his legs.

where he can get the most leverage on the very physical system. he has to actually move surfaces to fly..

so a centre stick is demanded by the controls and common sense. (KISS keep it simple stupid)

look at the HE111 for a lovely complex system for moving the controls to the left.

fly by wire.. the computer flies the plane so replace the stick with a computer interface. why the stick tends to be to the side.

modern airbuses look like two side by side office cubes and not a cockpit :)

the setup you have at home is irrelevant. :)

too many abstraction layers :)

if the plane is not fly by wire then the stick is placed in the centre of the airframe to make all the control runs the same length and to reduce complexity. for the controls to have the same weight they must be balanced. and that's a lot of wire to balance.

Not true at all ... most mil planes have rods/cables running along the side walls of cockpit ;)

Even F111 has rods on the ride side