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AMX underpowered?


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10 replies to this topic

#1
dpny

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Granted I don't have the English manuals yet, but performance seems very sluggish: very long take off roll, very slow acceleration and a top speed of about 500 kias at only 3,000 or 4,000 altitude.
"Though I fly through the Valley of Death, I shall fear no evil. For I am at 80,000 feet and climbing."
--Sign at the entrance to the old SR-71 base, Kadena, Okinawa.

#2
Fox3

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Don't know about underpowered but it does seem sluggish. I'll try unloading all the ordinance and see if it is any better.

There also seems to be points where the stick runs out of room, doesn't happen on anything else. Like full up or down just does about nothing for a while and then picks up.

Hopefully the manual will resolve some of this.

And yes, it does have an awfully long takeoff roll, but that could be ordinance weight, dunno...
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#3
kukuruz

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That's the AM-X, no more power than this.
Even if the english manual is not yet available, take a look at the Italian manual, page 89, 98, 99.
There's a table providing the weight for each configuration(without & with fuel), and then two charts giving
Rotate speed & Take-Off run (meters)
The trick is, after take off, not to climb more than 5, let the plane reach 250 Kts and then
it'll fly much better.
Try to never exceede 10 AOA (which is the first "-" on the left HUD sliding indicator)(each "." means 5)or the plane will lose its energy.
Just to let you know, I had fun givin the AM-X a, let's say, 50000 lbs thrust engine, it did take off VERY short, but didn't fly much faster due to its drag.
Anyway the cruise speed at low altitude can be reached by setting the engine 93% RPM; that will take you to about 0.7 mach. No need to fly faster, the target will wait.

#4
x-alberto

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There also seems to be points where the stick runs out of room, doesn't happen on anything else. Like full up or down just does about nothing for a while and then picks up.



I know that feeling. I was surprised by that when I initially got the AMX from Filippo.
What I learned with time is that you need to take great care of your airspeed and that control surfaces really ask for speed....
Also, if you let RPMs drop, it will take a while before you get them back (that is a peculiarity of the engine)

As Filippo said, you should avoid flying with great AoA with low airspeed.





#5
x-alberto

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Even if the english manual is not yet available, take a look at the Italian manual, page 89, 98, 99.
There's a table providing the weight for each configuration(without & with fuel), and then two charts giving
Rotate speed & Take-Off run (meters)



Of course, if you experience aircraft performances that differ from the provided charts... let us know and we will investigate at once....





#6
dpny

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Thanks for the answers.
"Though I fly through the Valley of Death, I shall fear no evil. For I am at 80,000 feet and climbing."
--Sign at the entrance to the old SR-71 base, Kadena, Okinawa.

#7
x-alberto

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Thanks for the answers.


Please let me add that engine performances are very correlated to external temperature.

If you are flying in very hot air, especially at runway level, you will get lower performances.

Cold climate will give you more power, to the point that the internal EGT limiter will eventually click-in to prevent RPMs from getting dangerously high

Ciao
Alberto

Edited by x-alberto, 08 July 2011 - 07:14 AM.


#8
Thaeris

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I believe I've read in the past that the AMX wasn't ever a particularly amazing performer - If memory serves, the fighter has no afterburner. It is also of fairly conventional configuration, so super agility isn't something I'd be expecting, either. It's as it is designed - a light attack aircraft. Expecting more than that is probably quite a misconception.

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#9
kukuruz

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And, let me add, the default loaded configuration is the heaviest allowed.
I suggest you try a lighter one, maybe the Clean configuration, to practice base procedures.
You can read in the README file how to do it. (never "cut", just copy & paste)
Your opinion is always welcome, thank you.
Filippo

#10
Classic Jet Simulations

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A lot of jets especially the older ones aren't great performers and take a bit of effort to get up to speed. The T-33 that I've flown is like this as well. You have to do a very shallow climb until you get the flaps up and then the airspeed up (and AOA down) especially on a hot day. After that, then you can start climbing.
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