speed command

[FLS]

It's also good for deadstick gliding. The default climb speed makes a good glide speed.

[Ciaphas]

Once level, a pilot is required to match the throttle to the current speed. If you come off stable climb and level the plane, the plane will accelerate if the throttle is not reduced. So once you’re level, it’s an iterative throttle process to stabilize at desired speed.

Depending on how fast I reach alt and how far away the target is from my go level. I will typically let the AC hit max speed, calibrate and break ground targets.

If I have a short target, I jockey the throttle to  zero out my E6B.


Sent from my iPhone using Tapatalk

[100Coogn]

It's also good for deadstick gliding. The default climb speed makes a good glide speed.

Yes it does. 

Coogan

[diaster]

Basicly The speed command functions like FLC, Flight Level Change in a standard autopilot. The computer will endeavor to maintain the speed not the angle.

[Vinkman]

It does't function in a way that is very functional. 

A speed command that controlled the level speed of the plane by varying throttle would be much more useful. 

[FLS]

Auto-speed does exactly what it's supposed to do.  It's not meant to do what you want it to do.

Use the same manifold and RPM settings in auto-level flight and you'll stabilize at the same speed.

[Vinkman]

Auto-speed does exactly what it's supposed to do.  It's not meant to do what you want it to do.

Yes I know what it does. That's not very useful.

Use the same manifold and RPM settings in auto-level flight and you'll stabilize at the same speed.

Yes I know, but it takes 3-6+ minutes for a plane to stabilize it's speed in level flight. throttle settings for a given speed will vary by alt and load out. A speed controller would do it much faster, the same way auto climb reached max climb rate for a given throttle setting and load out in seconds. It usefulness in bombing is that salvos and delays can be set for a given forward speed to maximize bomb coverage. Many folks bomb.  All the fun math that can worked out only to have to take forever to stabilize at the target speed.  So reaching target speed quickly when level is, to me, much more useful than a target speed when climbing which isn't that useful. With the former more useful than the latter, why do have the less useful one?

[FLS]

A speed controller would only reduce the throttle, you can do that yourself.

Then, after you slow down enough, set the manifold and RPM for the speed you want to stabilize at. You'll have to learn the settings you want to use.

I understand why you want it to work differently but then it would be simply a level bomber feature instead of generally useful for all aircraft.

[Vinkman]

A speed controller would only reduce the throttle, you can do that yourself.

It would Advance and reduce as required, but the real advantage is quick convergence and reduced pilot workload. Remember a buff pilot had to man the guns, fly the plane, line up the target, calibrate, set salvo & delay, and drop an each target. He's a bit over loaded. If your cal speed and actual speed are off by 3-5 mph and you miss.

Then, after you slow down enough, set the manifold and RPM for the speed you want to stabilize at. You'll have to learn the settings you want to use.

yes that is the work around. But is not as easy or effective as it seems. Take a fair amount bombardier CPU time to get this dialed in.

I understand why you want it to work differently but then it would be simply a level bomber feature instead of generally useful for all aircraft.

We don't have to choose. we can have both.    I think it would be useful for planes with slow reaction times. 262, Arado, 163, all buffs. Also if you added it as a feature, and checked the number of times it was used in climb mode and level mode, you'd find the latter used much more often... by me at least. 

[FLS]

You want a new auto pilot feature that makes bombing easier.

You should post in the wishlist. 

[Vinkman]

Probably.  I think I’m just curious how a speed command was developed that varies climb rate to hold a speed, vs cruise control. Who asked for the first one?  Doesn’t it seem like a unusual speed control method to program? 

[FLS]

I think it's generally useful for all aircraft. You can set your climb rate, descent rate, glide speed, and use your throttle to set altitude.

[mikeWe9a]

Probably.  I think I’m just curious how a speed command was developed that varies climb rate to hold a speed, vs cruise control. Who asked for the first one?  Doesn’t it seem like a unusual speed control method to program?

The speed mode isn't really an autopilot input - it simply sets the trim to a set location such that a centered stick commands a specific angle of attack based on the weight on the aircraft (and possibly the center of gravity, if the system even models c.g. shifts due to ordnance and fuel).  This angle of attack is such that the aircraft develops 1g of lift at the desired airspeed.  If the speed is less, the aircraft develops less lift and the nose drops, and vice versa.  You may note that this can and does result in overshoots and oscillation around the desired speed if it is substantially different from the actual airspeed or if the aircraft is not in stable flight.

Mike

[Vinkman]

Understood Mike.     I'm asking what the usefulness of that mode is. IF I set the speed in a fighter of say 200 mph at 5K, I might end up at 25K when I reach my destination because the my throttle setting was too high and the plane entered a climb to maintain set speed. If I the throttle is too low, I would hit the ground.

I guess all auto pilots only have control of the elevators and ailerons, not the throttle. perhaps that was an actual WWII limitation and so modes programmed in AH are limited to same?

[Mongoose]

Understood Mike.     I'm asking what the usefulness of that mode is. IF I set the speed in a fighter of say 200 mph at 5K, I might end up at 25K when I reach my destination because the my throttle setting was too high and the plane entered a climb to maintain set speed. If I the throttle is too low, I would hit the ground.

I guess all auto pilots only have control of the elevators and ailerons, not the throttle. perhaps that was an actual WWII limitation and so modes programmed in AH are limited to same?

Most World War II airplanes didn't have any auto pilot at all.   As I understand it, the auto trim and speed commands are there to help make up for some of the things that you have in a real airplane that you don't have at your computer desk.  As Hitech explained, you can't trim a spring loaded joystick the same way you can trim an airplane in true flight.