The A2A Simulations Community

Accu-feel , thank you !!
I went flying another devs P51 and started to get the overspeed judders at 250 mph . I thought this was a bit low and adjusted the slider and in a 500mph dive didnt get any shakes but plenty of wind !

Question:
what speed IAS should the airframe start to react ? also messed around with the mach slider but doesnt this change with altitude ? So what is the interaction between the mach number and IAS , can one override the other ? ( with accufeel )

So what figures -IAS and mach - would I put on the sliders for a Mustang ?

While I am here I may as well ask about the stall angle of attack too !

Cheers ..Alan

I am guessing that those figures should be in the aircraft.cfg...

What is the redline speed on the ASI dial?

Don't forget you may have to convert IAS mph to IAS knts...

A

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EVGA GTX670 2Gb, Windows 7HP on RaptorX 300, FSX on OCZ Vertex2 240Gb SSD

Taken from the cfg :
performance = Empty Weight: 6985 lbs. Max Power: 1720 Hp. Manoeuvering speed: 309 mph @ 9.0 g. + Max speed: 440 mph @ 25000 ft. Max speed at sea-level: 388 mph. Rate of Climb: 4000 ft/min @ 170 mph.

The red line on instrument is just a whisker over 500mph. Haven't converted to knts yet.

So we still have the altitude difference, guess we make an average max speed ?

Do we have to sync in the mach no. ?

Its getting late here ,must go to bed soon

I think the real figures for the Vnes are 438 knots (505 mph on the asi) and I've read an actual critical mach of .82. If it were me, I would set the sliders at 438 knots and be inclined to set the Mach at .80, a little lower, just to account for any margins that they may have already built in to Accu-Feel. Note that an old manual I have sitting around suggests a Mmo of .75 Mach, but I think that the actual critical mach is .82. Probably the A2A boys and girls can give you a more definitive figure and a better suggestion as to where to set the Mach slider, but otherwise, thats where I would put it.

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1)i7 980x 4.35 ghz, gtx 470s SLI, Matrox th2go, Creative x-fi
2)i7 2600k, Gigabyte z68x, gtx 285s sli

Thanks BigJuicySpider ...(wonder if he eats them ? ).
I'll pump thoses figures in and take her for a ride . Cheers

Maybe one for later is the altitude difference. I am trying to get my thinking right here but stall would change with altitude and vne ? Maybe its in the too hard basket.

I picked the name bigjuicyspider because I was looking at a front-on view of the Stratocruiser while I was signing up for these forums and the first thing that popped into my head is "hey that looks like the face of a gigantic spider". Yes, it is a stupid name, but it is what I'm stuck with...

As far as Altitude goes, you don't need to tweak any more in Accu-Feel. The Mach number/IAS correlation is already being taken into account, by definition. Like I said above, the real world chart pegs the "Max Allowable Diving Speed" at .75 Mach or 505 mph (equal at 5000 ft msl), whichever is lower. But at 40,000 ft, mach .75 is equal to 260 mph IAS, so you aren't running into the structural limits on the airframe, only that mach buffet. This is just straight from a chart in this manual http://www.amazon.com/P-51-Mustang-Pilo ... 2&sr=8-7#_

So why did I tell you to put your Mach Buffet at .80 instead of .75 mach? Because I googled it and read on the intertoobs that the actual critical mach number was closer to .82 for the D, and .84 for the B model, and then lowered it just to provide a fluff factor . In other words, the chart in the manual is obviously providing a conservative safety margin to the actual onset of compressibility effects. So I think you are close enough to the actual buffet onset using the figure of .80 mach, but like I said, if you want to know where A2A is going to place those for their P-51, you'll have to get the answer from them...

So Scott, where would YOU put those numbers in Accu-Feel if you were this guy?

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1)i7 980x 4.35 ghz, gtx 470s SLI, Matrox th2go, Creative x-fi
2)i7 2600k, Gigabyte z68x, gtx 285s sli

Thanks for taking the time Spider ,
I think part of my "problem" is just getting the hang of the new app. Yeah, I know its automatic and we can adjust to how we want it, but ...Like all others I want experience as real as possible and , well, I dont know what the real is . As already mentioned a sticky may be made with all the seperate aircraft tweeks listed , which would be just great. That way after the guys have discussed it we should end up with the best tweek for that particular airplane .
This is a very exciting app , with the planned developement coming its going to transform the sim. Lets hope the REX soon coming update does similar for the weather . What an awesome combo that will be !
Thanks again for the info , it helped .
Cheers ..Alan

edit ...indeed Scott , what figures would you use . I guess I'll find out when I get your Mustang !