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manico52

About IAS

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Hello,

I would like to use IAS button about to climb or descent at stable speed, but when I engage it, vertical speed increase quickly (more than 4000 ft/min).

Do you have any idea about this problem?

Thank you!

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Posted (edited)

I took mine on a short flight to use the airspeed to control climb. I turned on the autopilot and started the climb with altitude select at 1500'. Then turned on airspeed and used the thumbwheel to adjust speed. Throttle setting was at 90%, thumbed in 250 knots, nose dipped to increase speed and resumed climb. The speed indicator said 235. Did the same later for 260, nosed dipped and resumed climb at 245. It was not an erratic dip, only about 1000'. Lastly, I slowed to 235 in the climb and the nose pulled rapidly up 3000' but settled back down when I adjust the power up to smooth it out. I think this is the way it is supposed to work. I mostly use altitude select and power to control climb.

Bert may have worked on the autopilot xml in the past, not sure. You could send him a PM and ask if he made improvements. Don  Windows10/P3D4.4

Edited by D Nelson

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Posted (edited)

Thank you for your answer Don!

I 'm going to try your version because I selected speed (with small rotary knob on the corner of analogic airspeed indicator) and after that I turn on IAS mode.

Thumbwheel to adjust speed is the same i use? (Citation is the last version from Carenado, I use it with GTN 750).

 

Edited by manico52

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I have Xplane11 and P3DV4.4 

In P3DV4.4 IAS hold works flawlessly and I just love the way it uses pitch to maintain IAS during cruise climb.  But in Xplane11 it just bleeds off airspeed and I have to disengage the autopilot, engage VS hold, and yet VS hold still does not capture my assigned altitude, unlike P3DV4.4

I have opened a support ticket with Carenado.  I bought the C550 so I could integrate RealityXP with it, which I just love, way cool, a worthy purchase, even though it only has US airports in its Database.  I want the C550 in Xplane11 to work exactly like it does in P3DV4.4, I use both sims extensively depending on what photoscenery I am flying over.

Has anyone else tried the C550 in Xplane11?  Could RealityXP be causing problems?  I would not think so, since that is gps/destination oriented, not altitude oriented.

John

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Posted (edited)
On 4/16/2019 at 5:28 AM, D Nelson said:

I took mine on a short flight to use the airspeed to control climb. I turned on the autopilot and started the climb with altitude select at 1500'. Then turned on airspeed and used the thumbwheel to adjust speed. Throttle setting was at 90%, thumbed in 250 knots, nose dipped to increase speed and resumed climb. The speed indicator said 235. Did the same later for 260, nosed dipped and resumed climb at 245. It was not an erratic dip, only about 1000'. Lastly, I slowed to 235 in the climb and the nose pulled rapidly up 3000' but settled back down when I adjust the power up to smooth it out. I think this is the way it is supposed to work. I mostly use altitude select and power to control climb.

90% is in any case  way too low...and 90% of what? This doesn't mean anything. N1 would be a useful value.

The way you are trying to 'control' your climb is definitely not the way you would do it IRL (or in the sim).

Over and out. 

Edited by FDEdev

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