Cessna Citation x - Speed problem

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Cessna Citation x - Speed problem

Postby Sprocket » Mon Apr 28, 2014 7:25 am

Hi All,
I downloaded the Cessna Citation x, kindly presented by Alejandro Rojas Lucena, some time ago.
I like this ac, but I have a problem: :think:

This ac seems to seriously pick-up (increase) speed on the decent. For instance:

Example 1:
I am steady at 10000ft @ 230kts. ATC commands me down to 5300ft.
By the time I level out at 5300ft, (-1800ft/min), I reach 295kts. (65kts speed increase)
ATC commands me down further to 4300 ft, and then 2000 ft. By now I reach 310 kts, with a mere 17 miles to go.

Example 2:
I am steady at 10000ft @ 230kts. ATC commands me down to 5900ft.
This time I disengage the auto throttle and completely cut the throttle.
Again, by the time I level out at 5900ft, (-1800ft/min), I reach 295kts. (65kts speed increase)
ATC commands me down to 2000ft on the final, and I am still at 270kts, heading for 300+, 17 miles to go.

There is no way to get down to a safe touch-down speed.
Is there something wrong with this AC, or is it me? (Prob yes)
Am I supposed to apply spoilers with this ac, and if so, how? What am I doing wrong?

(When I repeat this flight exactly with any other AC, there is no problem)
Thanks
Jan
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Re: Cessna Citation x - Speed problem

Postby alrot » Mon Apr 28, 2014 12:17 pm

I heard about that Alejandro Rojas ,he's a handsome guy :lol:

I hope we're talking about the last one I made the version "ultra" its the first one on this page http://simviation.com//fsnd/Downloads.htm

I have also heard in some other place about this issue ,this can be fix by increase the dragging something

open Aircraft.cfg with notepad (make a backup first!) and look these lines

[flight_tuning]
cruise_lift_scalar=1.0
parasite_drag_scalar=1.0 <------increase the rate to 1.5 or 2.0
induced_drag_scalar=1.12
elevator_effectiveness=1.0
aileron_effectiveness=1.0
rudder_effectiveness=1.0
pitch_stability=1.0
roll_stability=1.0
yaw_stability=1.0
elevator_trim_effectiveness=2.0
aileron_trim_effectiveness=1.0
rudder_trim_effectiveness=1.0

tell me how it goes , I can't test it myself right now as soon I get back home I'll check it myself

Alejandro
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Re: Cessna Citation x - Speed problem

Postby Sprocket » Tue Apr 29, 2014 4:10 am

alrot wrote:I hope we're talking about the last one I made the version "ultra" its the first one on this page http://simviation.com//fsnd/Downloads.htm


Hi Alejandro,
Thanks for the reply...much appreciated.
Yes, this is indeed this one I am referring to.

I have changed the:
parasite_drag_scalar=1.0 to 1.9

This is making all the difference and the ac now only picks up about 10 kts on the decent.
I will test this further, but I already think it is good. :clap:

Thanks for the help. Great AC this, and I am very happy this was not a major issue. :dance:
So, all is good..thanks for help.

Jan
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Re: Cessna Citation x - Speed problem

Postby Speed of flight » Tue May 13, 2014 12:31 pm

For what it's worth, the CX does deploy spoilers on descent, at least as needed. With that much an increase in speed, you should have a good amount of drag from 7-15* flaps, and modulating the spoilers as needed.
He did a great job with that bird! Maybe an option for the one with the elliptical winglets? Just a thought... :)
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Re: Cessna Citation x - Speed problem

Postby Sprocket » Tue May 13, 2014 1:32 pm

Speed of flight wrote:For what it's worth, the CX does deploy spoilers on descent, at least as needed. With that much an increase in speed, you should have a good amount of drag from 7-15* flaps, and modulating the spoilers as needed.


Thanks..much appreciated.. I'll certainly look into that and give it a go.
I also agree that it is a great ac, and I am trying to learn as much as I can on this ac, but I still have a long way to go I'm sure :think:

Jan
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Re: Cessna Citation x - Speed problem

Postby Flacke » Tue May 13, 2014 1:51 pm

Hello, the Citation X is all about SPEED. You have to learn to fly it like a sleek high-speed aircraft. Its not a KingAir. The C-X has huge engines and residual thrust even at idle power and it has highly swept-back wings. Any time you lower the angle of attack it will pick up speed immediately. You have to learn how to slow the airplane down early in your descents and approachs. You use whatever power setting you need and you increase angle of attack to slow down, then you use some flaps to slow down more and use the landing gear to add drag and slow it down. You can use spoilers as necessary and increase the flap settting until you have the proper speed for approach. It takes practice, they don't just hand a Citation X to any Private Pilot and say "here, go fly it". Pilots need to be specifically trained to fly such a high-speed Mach .92 [new model is a Mach .935 airplane].
So keep training yourself on how to slow the airplane using all available drag producing devices and don't put the nose down when you are descending or trying to slow it down. With practice you will learn to fly it and it will be very rewarding when you find yourself gaining the skills to fly it well. Don't give up, just practice until you are comfortable . Have fun.
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