reported ATC Approach Mode

[AG-51_Razor]

Thanks for your responses guys, much appreciated.

[Dr. Anti-Vehicle]

8 hours ago, IvanK said:

My experience was all land based. For us we actually used power as the primary control of AOA down final rather than the NAVY method of using pitch. As such our everyday technique in manual thrust was the same as is required in ATC mode.. Pitch for flight path and power for AOA. How many times was ATC used in approach mode ? A personal thing as nothing was mandated based on recovery conditions. In my case probably on about 25% of instrument approaches ...ILS/GCA/TAC/VOR. Having said that if I was shooting an approach to no shit minimas I would not hesitate using ATC.

Used correctly ATC approach mode was smooth and very accurate. The typical pitch corrections you make on an instrument final were easily handled by the ATC.

Another snippet ATC cruise mode actually refrences TAS not IAS at time of selection.

Excuse my stupidity. Why and how throttle can control AOA? Why not trim?

[tech_op2000]

On 10/21/2021 at 2:43 AM, Swiftwin9s said:

Kinda sounds like it's behaving exactly the same as it was before they 'added' it.

In the case of it throttling back too much perhaps. In terms of its basic functionality I don't believe so. I may be completely wrong about this system as I don't have any real experience with it but based on my aeronautics experience and my assumptions about this system, here are my thoughts:

Prior to the addition of the approach capability of the ATC, if it were enabled in a landing configuration, it would attempt to maintain an airspeed. This would be perfectly acceptable for level flight and gradual climbs and descents. This would not be desirable for turns though. It would also be a bit sluggish to respond as I'll describe below:

When a plane rolls to enter a turn, some of the lift is directed sideways instead of up. In order to maintain altitude in a turn, the plane must generate additional lift. It can do this by either increasing AOA or by increasing speed. 

In the non approach implementation this would cause the plane to maintain the same speed with ATC in a bank and the pilot would have to increase AOA to maintain level flight. 

With the approach Implementation, I believe the plane will now increase thrust as necessary to maintain AOA in a bank, resulting in an increase in airspeed. (an increase in thrust results in an increase in speed if AOA is maintained, causing a proportional increase in lift)

Also, in the approach mode, a deviation from the desired AOA will immediately begin a throttle response, even though speed hasn't yet changed. In the non approach mode I don't believe the throttle response would be as immediate. 

Edited October 22, 2021 by tech_op2000

[Swift.]

13 minutes ago, tech_op2000 said:

In the case of it throttling back too much perhaps. In terms of its basic functionality I don't believe so. I may be completely wrong about this system as I don't have any real experience with it but based on my aeronautics experience and my assumptions about this system, here are my thoughts:

Prior to the addition of the approach capability of the ATC, if it were enabled in a landing configuration, it would attempt to maintain an airspeed. This would be perfectly acceptable for level flight and gradual climbs and descents. This would not be desirable for turns though. It would also be a bit sluggish to respond as I'll describe below:

When a plane rolls to enter a turn, some of the lift is directed sideways instead of up. In order to maintain altitude in a turn, the plane must generate additional lift. It can do this by either increasing AOA or by increasing speed. 

In the non approach implementation this would cause the plane to maintain the same speed with ATC in a bank and the pilot would have to increase AOA to maintain level flight. 

With the approach Implementation, I believe the plane will now increase thrust as necessary to maintain AOA in a bank, resulting in an increase in airspeed. (an increase in thrust results in an increase in speed if AOA is maintained, causing a proportional increase in lift)

Also, in the approach mode, a deviation from the desired AOA will immediately begin a throttle response, even though speed hasn't yet changed. In the non approach mode I don't believe the throttle response would be as immediate. 

 

I wasn't talking about the cruise ATC. I meant how approach ATC has been behaving in DCS prior to this update. Namely pretty good other than it cutting the throttle for several seconds at engagement

[VFA41_Lion]

Approach ATC worked okay for me in testing, but i was at 3000 lbs fuel and no stores. Maybe it has trouble if you are above trap weight?

[oldcrusty]

I tested it some more. Seems like there's no need to trim to any specific AOA. Once ATC is engaged and settles after the initial 'craziness' it slowly gets to the middle of a bracket. It disables the manual trim... fine, I can deal with it.  In order to avoid the scary power idle dip and loss of altitude (around 350 ft) I tried engaging the ATC right after lowering gear/flaps at around 220 or in the break. The 'ATC' did not show on the HUD until I slowed down a little. I guess it's a function of LE flaps extending to a certain angle (I don't remember exactly) so... as I'm leveling and slowing down, the worst of the initial power dip is behind me. Still, the corrections are slow. The stick movements need to be quick, just taps up and down instead of smooth deflections. (I've read that's the way it's done in RW) Straight in approaches are fairly easy. Case I... I've managed a few but they were not pretty.  The power corrections during turns are actually not that bad but the roll out in the groove with only seconds to get everything on numbers, not that easy... for me at least.  

The main 2 problems in my opinion are: the power dip on ATC start and the corrections are slow. If ATC is engaged when approaching on-speed (trimmed or not) the loss of power and altitude is unacceptable.

[BIGNEWY]

we have a report open for tweaking, please wait for future changes

 

thanks