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Other AI Aircraft Question?

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col1948
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Other AI Aircraft Question?

Post by col1948 »

Have you ever noticed when floowing or viewing a particular aircraft if you happen to see another AI aircraft flying by they seem to be travelling a lot faster and covering more ground that the one you are following, they seem to shoot across the sky?

So are they really or if not what causes this optical illusion?
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Firebird
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Re: Other AI Aircraft Question?

Post by Firebird »

I know of one possible cause especially with civvie traffic. The cause is that most AI models have different cruise speeds, which for mil stuff is fine.
However for civvie stuff most airliners fly in controlled airspace and are restricted in speed to 250 KIAS. The simple reason is that you can't have aircraft traveling at the same level at different speeds. It was one of the big rule changes that came out of the 1956 Grand Canyon air disaster.
This is why WoAI had, and maybe still have, all their aircraft speeds set to 250 kts. Unrealistic but they don't overtake.

If you use a compiler that uses the aircraft cruise speed to override the traffic speed then you can get problems.

Now if you had two aircraft of the same type at the same level and you are following one and it falls behind the other one then this is something else.

Quite often I have been watching a pair of mil aircraft, at the same level , and the distance only changes when one is higher or lower than the other.
Steve
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col1948
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Re: Other AI Aircraft Question?

Post by col1948 »

Hi Steve, When you say 'All aircraft speeds set to 250 kts' are you referring to the speed in TTools or is this in the aircraft cfg?

I seem to remember years ago people used to set all aircraft speeds to 200 in TTools, but I've seen flight plans with various speeds, also I did a test once and set the speed to 10 in TTools but the aircraft still went at the speed set in cfg which I read later that is what the sim does.
Again I am probably way off track lol.
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Firebird
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Re: Other AI Aircraft Question?

Post by Firebird »

Sorry, my mind played tricks on me. Yes it was 200 kts in the raw flightplan files not 250.

The speed that ttools used was in the aircraft.txt file but a lot of others use the aircraft cruise speed. AIFP has a switch that means you can use which one you prefer. For example you can keep your 737 plans going at 200kts or you can have it set to 477kts, depending on model.

To me there is no right way of doing it. To be honest probably the best way of doing it for jet airliners is to set the max_mach parm to a standard number, such as 0.8, and then let the flight level decide the speed to fly at. M0.8 at a level is the same for all aircraft.
This however is an idea that I have and have done no testing on it to see what the impact is.
Steve
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