Does Real-World Flight Control Hardware Have Detents?

[CrownCityMisfits 58]

I am a reasonably knowledgeable flight simmer but have zero experience flying real airplanes. The closest I come is taking may kids to KEMT a couple times a month for breakfast at Annia's Kitchen, just so we can watch the GA traffic arrive and depart.

 

I'd really like to know if real-world aircraft controls have detents. Or are they just "loose" without any kind of corrective measure other than wind forces. My sim hardware has detents, but I see many people going through great lengths to reduce or eliminate them. I understand why, as far as precision control is concerned - especially on landing.

 

Do detents exist on real-world...

 

1. Yokes

2. Pedals

3. Throttles

4. Flight Sticks

 

I am mainly concerned about GA controls, but if there are differences between GA and military and commercial, I'd love to know about that as well.

 

Thanks.

[Chock 17,769]

Never personally come across a joystick or rudder pedals in a real GA aeroplane which had a detent. The spoilers usually latch shut on the gliders I fly, to prevent them popping out under the low pressure on the top of the wing, which i suppose you could call a detent, because it's often quite a pull that is required to get them to unlatch.

 

Apart from that, everything else is usually free floating, which is why you need to place control locks on things like the rudder when parked in the open, in order to stop the rudder from banging about in strong winds.

[CrownCityMisfits 58]

Apart from that, everything else is usually free floating, which is why you need to place control locks on things like the rudder when parked in the open, in order to stop the rudder from banging about in strong winds.

 

Thanks for the insight and taking the time to reply. Cheers.

[richjb2 195]

I can't say that I have flown a light GA single engine or multiengine airplane that has primary control surface detents. These surfaces usually have direct linkage between the control surface and the control stick/wheel. 

 

In larger, transport category airplanes, you may run across a detent.  In the Challenger 300 that I fly, there is a noticeable detent in the control column when the elevator is moved.  The elevator is hydraulically powered, but with direct linkage as well.  it takes about 1/4" to 1/2" of fore-aft stick movement to break the detent and effect noticeable elevator movement.  Bombardier calls this the "sneeze protection" that prevents inadvertent movement of the elevator for slight stick nudges. In contrast, the Dassault Falcon 2000 that came out of prior to the CL300 had no noticeable detent and much, much lighter control forces, almost fighter-like owing to Dassault's history with the Mirage fighters. I have not seen detents in the aileron or rudders in any transport category airplane.

 

Detents in throttles are becoming quite common in jets.  Detents are uses to FADEC or engine computer specific thrust settings, for example takeoff/go-around thrust, maximum continuous thrust (MCT), and automatic performance reserve (APR) thrust.  I don't of any prop airplanes that have detents for takeoff or maximum continuous power.  It's been quite some time since I have flown propeller airplanes.

 

Hope this helps,

 

Rich Boll

Wichita KS

[CrownCityMisfits 58]

Hope this helps,

 

Rich Boll

Wichita KS

 

It absolutely does, Rich. Very interesting, and helps me understand the wide variety of control types out there, and what it may take to simulate each of them. Much appreciated for sure.

[HighBypass 2,339]

Some military fast jets have detents to denote max dry thrust then afterburner. The Tornado has a sideways detent - you rock the throttles outboard.

[CrownCityMisfits 58]

The Tornado has a sideways detent - you rock the throttles outboard.

 

Cool. Extra layer of protection against accidental use I suppose.

[Mickeyj 35]

I flew EMB 190/195 and fly CRJ900 now again. Both tubes have detends in elevetor/aileron as well as the rudder pedals and the throttles. In flight school i was in Beech Bonanza, Baron and Seneca V. The controls did not have noticable detends. I also had the oportunity to fly the Beech Mentor T 34 piston version You dont really have any detends. Maybe at the end of the year i can give some feedback about the A340-300.

 

Hope that helps

[Rossco 23]

In the lighties Iv'e flown there have never been any detents as the other guys have mentioned.

 

But what does obviously happen when you go flying is the force of the air flow over the controls tends to centre them, much like our spring centred controls. So I really have never gotten hung up about detents because of this. Feels fine to me, but then I changed over to a PFC yoke years ago (that has detents too).

[HighBypass 2,339]

Cool. Extra layer of protection against accidental use I suppose.

 

It's more than that though. If MAX REHEAT is selected (English for afterburner  ), then you can rock the throttles outboard to enable the selection of COMBAT mode (it lifts a few of the temperature parameters on the engines so you have a little extra oomph for a couple of minutes). If you're operating in dry thrust, then rocking the throttles outboard will arm the spoilers (lift dumping, left throttle only) and reverse thrust buckets (right throttle) for landing.

 

The gliders I fly don't have any detents, apart from the airbrakes to keep them shut, as Chock noted.

[CrownCityMisfits 58]

Maybe at the end of the year i can give some feedback about the A340-300.

 

Yeah that would be cool. Hit up this thread again if you remember.

 

But what does obviously happen when you go flying is the force of the air flow over the controls tends to centre them, much like our spring centred controls. So I really have never gotten hung up about detents because of this. Feels fine to me, but then I changed over to a PFC yoke years ago (that has detents too).

 

My CH setup has been bothering me a little because the detents seem very strong. Subtle movements when landing or while on tarmac can be difficult. Been considering the spring mods, which is really what prompted me to create this topic in the first place. Does the PFC have a spring that pulls it back to center?

 

It's more than that though. If MAX REHEAT is selected (English for afterburner  ), then you can rock the throttles outboard to enable the selection of COMBAT mode (it lifts a few of the temperature parameters on the engines so you have a little extra oomph for a couple of minutes). If you're operating in dry thrust, then rocking the throttles outboard will arm the spoilers (lift dumping, left throttle only) and reverse thrust buckets (right throttle) for landing.

 

Incredible machines.

[busdriver 258]

On the Airbus I fly,  the throttles can only be moved manually into one of five gated positions. You could think of them as detents.

 

Take-Off/Go-Around (TO/GA) 
Continuous Thrust (FLX/MCT) 
Climb (CL) 
Forward idle 
Reverse Idle

 

Hope this helps somewhat.... Happy to elaborate.

[CrownCityMisfits 58]

On the Airbus I fly,  the throttles can only be moved manually into one of five gated positions. You could think of them as detents.

 

Take-Off/Go-Around (TO/GA) 

Continuous Thrust (FLX/MCT) 

Climb (CL) 

Forward idle 

Reverse Idle

 

Hope this helps somewhat.... Happy to elaborate.

 

I didn't know that. So, is everything in between the 5 positions controlled by autopilot? Or do you have another way to control thrust besides the throttle?

 

Do you have a sim hardware setup that reflects this?

[busdriver 258]

I didn't know that. So, is everything in between the 5 positions controlled by autopilot? Or do you have another way to control thrust besides the throttle?

 

Do you have a sim hardware setup that reflects this?

 

Hi, here is a bit more:

 

Lets say we are at the gate, and have computed our take-off performance and based on the numbers, we won't need maximum thrust take-off, so we can save some wear and tear on the engines, using the flexible take-off thrust setting (i.e. reduced thrust on Boeing's) 

 

At the end of the runway, with the clearance received and the aircraft ready to go, we put the throttles into the FLEX/MCT gate. 

 

The FADEC system now knows "the thrust rating limit" (i.e. FLEX) and the FADEC computes "the thrust value limit". Both are displayed on the right side of the Primary Engine Display. 

The actual thrust is set to match this and is displayed on the left of the PED by a pointer on 2 (4 on A340) white dials representing the current setting. There's also a digital indicator incorporated into each of these dials. 

 

Shortly after take-off it's time to reduce thrust (normally at 1500ft unless otherwise stipulated by local regulations), so we move the throttles to the gated CL position. Again, the FADEC system now feels the new "the thrust rating limit" (i.e. CL) and the FADEC  recomputes "the thrust value limit". 

The new data is once again displayed on the right side of the Primary Engine Display and the actual thrust is set to so as to give us the flight parameters (IAS, VS, etc...) programmed via our MCDU. This might very well be below the thrust value limit as depicted on the right of out PED. 

 

From now on, all changes to our thrust will be done in order to keep up with the demands we made to the naviagtion system via the MCDU.  We can follow these changes to our actual thrust setting only on the pointers of the white dials on our PED. 

 

During the rest of the climb, level off, cruise, descent and approach the throttles aren't moved anymore. 

 

This means the "thrust rating limit" as indicated on our PED remains unchanged at "climb".  However, due to changing ambient conditions "the thrust value limit" as computed by the FADEC will change and so will their indication on our PED.  As always, actual thrust is set according to our needs and depicted by the pointers of while dials on our PED. 

 

As an example, lets imagine a 10NM final, and you want to disconnect the A/THR to fly manually.  The A/THR is still in the CL gate because that's were we set them shortly after take-off...  All you need to do is to set the throttles so as to match your current thrust setting as depicted on the white dials and push the red disconnect buttons on the left and right side of the throttles.

 

You know have full control over your engines within its FADEC protection limit. 

 

And I have not replicated this in the sim, I'm not smart enough to figure that out!!

[CrownCityMisfits 58]

Hi, here is a bit more:

 

Lets say we are at the gate, and have computed our take-off performance and based on the numbers, we won't need maximum thrust take-off, so we can save some wear and tear on the engines, using the flexible take-off thrust setting (i.e. reduced thrust on Boeing's) 

 

At the end of the runway, with the clearance received and the aircraft ready to go, we put the throttles into the FLEX/MCT gate. 

 

The FADEC system now knows "the thrust rating limit" (i.e. FLEX) and the FADEC computes "the thrust value limit". Both are displayed on the right side of the Primary Engine Display. 

The actual thrust is set to match this and is displayed on the left of the PED by a pointer on 2 (4 on A340) white dials representing the current setting. There's also a digital indicator incorporated into each of these dials. 

 

Shortly after take-off it's time to reduce thrust (normally at 1500ft unless otherwise stipulated by local regulations), so we move the throttles to the gated CL position. Again, the FADEC system now feels the new "the thrust rating limit" (i.e. CL) and the FADEC  recomputes "the thrust value limit". 

The new data is once again displayed on the right side of the Primary Engine Display and the actual thrust is set to so as to give us the flight parameters (IAS, VS, etc...) programmed via our MCDU. This might very well be below the thrust value limit as depicted on the right of out PED. 

 

From now on, all changes to our thrust will be done in order to keep up with the demands we made to the naviagtion system via the MCDU.  We can follow these changes to our actual thrust setting only on the pointers of the white dials on our PED. 

 

During the rest of the climb, level off, cruise, descent and approach the throttles aren't moved anymore. 

 

This means the "thrust rating limit" as indicated on our PED remains unchanged at "climb".  However, due to changing ambient conditions "the thrust value limit" as computed by the FADEC will change and so will their indication on our PED.  As always, actual thrust is set according to our needs and depicted by the pointers of while dials on our PED. 

 

As an example, lets imagine a 10NM final, and you want to disconnect the A/THR to fly manually.  The A/THR is still in the CL gate because that's were we set them shortly after take-off...  All you need to do is to set the throttles so as to match your current thrust setting as depicted on the white dials and push the red disconnect buttons on the left and right side of the throttles.

 

You know have full control over your engines within its FADEC protection limit. 

 

And I have not replicated this in the sim, I'm not smart enough to figure that out!!

 

Thank you very much for that simple explanation of a very complex process - a process that is 100% new to me.

 

See, I've been flying GA aircraft in my sims for years, but never considered flying passenger jets or larger commercial aircraft. I don't fly anything without a prop, and the Twin Otter is the largest addon aircraft I've ever purchased, excluding the A2A B-17.

 

Your insight certainly fuels my innate desire to learn more about flight. I really appreciate it. So glad I asked my original question in this thread.

 

Cheers.