Airspeed in the Thirdwire games

[Rambler 1-1 9]

I was playing around with my A-7 and I was on a strike mission escorted by a bunch of F-4s. I noticed that my Corsair, loaded with four LAU-10 pods and 2 'winders, cruised at 503 knots, while the F-4s, with four sparrows and 'winders each, cruised in the high 400's. Does the A-7 really cruise faster than an F-4?

 

This raised another question. I noticed that most planes that should be able to go mach 2 or so only get up to about 800 knots. According to my calculations, Mach 2 is 1,322.9 knots, but I have never used a plane in SF that can reach that without being modded (heheheh...). So is the airspeed as displayed in SF the actual speed your plane is going?

 

It must be accurate in the lower speeds, because stall is usually more or less where it's supposed to be.

[Caesar 305]

http://forum.combatace.com/index.php?showtopic=26920

 

see here^^

[column5 63]

This issue of speed came up in a heated maelstrom yesterday so I'll try to answer your questions.

 

First thing is to know the difference between Indicated (or Calibrated) Airspeed and True Airspeed.

 

From Wikipedia:

 

Indicated Airspeed

 

True Airspeed

 

I can't give you the mathematical part of it, but in really really simple terms (that even I can understand), the higher you fly, the more IAS and TAS will diverge because airspeed is detected by a pressure sensitive instrument, and the higher you fly, the lower the air pressure.

 

So, let's say you are cruising in an F11F Tiger at 350 knots IAS at 10,000 feet. Your true airspeed is going to be about 440 knots.

 

Here is a quick tool to help you convert between IAS and TAS at various altitudes:

 

http://www.paragonair.com/public/aircraft/calc_TAS.html

 

The question you asked, does the A-7 cruise faster than the F-4, is complicated. Assuming that you choose a cruise speed for best fuel economy at a particular aircraft weight and altitude, there may be circumstances where the A-7 would actually crusie faster, even though it is a slower overall aircraft.

 

Here is a chart from the F11F pilots manual showing recommended cruise speeds in clean configuration at 10,000 ft.

 

 

Note that the recommended cruise speeds range from 300-350 knots IAS, or 350-400 knots TAS. This is at odds with what most websites will tell you the cruise speed for this aircraft is, because most websites don't have detailed technical info and don't take into account the information I've outlined above. You really need a -1 to get the good info.

 

To address the A-7 specifically, since I did that flight model, I almost certainly have it too high for a couple of reasoins. First, I was less experienced when I did that FM, and second, the game changed recently so that the engine thakes the value for CruiseSpeed and treats it as the target IAS rather than TAS. It used to aim for the CruiseSpeed as the target TAS, so planes that have not been updated for WOI/SP5 are going to tend to cruise faster than they ought to. Rest assured that the flight models I have been involved with will be updated.

 

Based on the above, you should be able to work out the anser to the question about Mach 2 versus 800 knots IAS...

 

I hope this helps!

[Fubar512 1,350]

Well, I've just added this to the knowledge base: http://forum.combatace.com/index.php?showtopic=26955

[Stick 773]

This reminds me of my father sitting down with junior pilots at home over early morning breakfasts and literally beating the basics into them before their check flights.

[Rambler 1-1 9]

ok, I think I understand. I definetly know the IAS and TAS, I learned that from my dad. I looked up the corsair's universal cruise speed and put it into the ini file so it's nice and slow now .

 

Also, at the altitude I was at, Mach 2 was about 950 knots TAS, and I was going 820 knots indicated. in that situation, I was going 928 knots true (if my math is right), so i was pretty close to mach 2. I was also in an F-14 with weapons and a pretty full fuel load, so I think the top speed was accurate.

 

Also, I'm gonna keep that chart.

Edited March 26, 2008 by Rambler 1-1

[Stwa 18]

Just fly closer to the ground and you won't have to cart around the charts or do any math.

 

Its generally best anyway. :yes:

[JediMaster 451]

The other thing is AI may not fly the plane at the speeds you would if you were in it. They can do odd things at times.

[+Brainless 1]

This issue of speed came up in a heated maelstrom yesterday so I'll try to answer your questions.

 

First thing is to know the difference between Indicated (or Calibrated) Airspeed and True Airspeed.

 

From Wikipedia:

 

Indicated Airspeed

 

True Airspeed

 

I can't give you the mathematical part of it, but in really really simple terms (that even I can understand), the higher you fly, the more IAS and TAS will diverge because airspeed is detected by a pressure sensitive instrument, and the higher you fly, the lower the air pressure.

 

So, let's say you are cruising in an F11F Tiger at 350 knots IAS at 10,000 feet. Your true airspeed is going to be about 440 knots.

 

Here is a quick tool to help you convert between IAS and TAS at various altitudes:

 

http://www.paragonair.com/public/aircraft/calc_TAS.html

 

The question you asked, does the A-7 cruise faster than the F-4, is complicated. Assuming that you choose a cruise speed for best fuel economy at a particular aircraft weight and altitude, there may be circumstances where the A-7 would actually crusie faster, even though it is a slower overall aircraft.

 

Here is a chart from the F11F pilots manual showing recommended cruise speeds in clean configuration at 10,000 ft.

 

 

Note that the recommended cruise speeds range from 300-350 knots IAS, or 350-400 knots TAS. This is at odds with what most websites will tell you the cruise speed for this aircraft is, because most websites don't have detailed technical info and don't take into account the information I've outlined above. You really need a -1 to get the good info.

 

To address the A-7 specifically, since I did that flight model, I almost certainly have it too high for a couple of reasoins. First, I was less experienced when I did that FM, and second, the game changed recently so that the engine thakes the value for CruiseSpeed and treats it as the target IAS rather than TAS. It used to aim for the CruiseSpeed as the target TAS, so planes that have not been updated for WOI/SP5 are going to tend to cruise faster than they ought to. Rest assured that the flight models I have been involved with will be updated.

 

Based on the above, you should be able to work out the anser to the question about Mach 2 versus 800 knots IAS...

 

I hope this helps!

 

 

This definitely needs to go in the KB a.s.a.p. as it's a continual re-occurring topic. I was going to add it to my guide but I think the KB is the right place for it

[Fubar512 1,350]

This definitely needs to go in the KB a.s.a.p. as it's a continual re-occurring topic. I was going to add it to my guide but I think the KB is the right place for it

 

Have you checked the knowledge base lately? As in the last 24 hours?

[+Brainless 1]

Have you checked the knowledge base lately? As in the last 24 hours?

 

No I haven't but I will do. Thanks.

 

I just looked. Yes very good. I've just added the question and your link to my guide. Excellent

Edited March 27, 2008 by Brainless

[Stick 773]

I hope this settles it.

 

Check the mach indicator.

We are at optimal altitude and i believe she's doing Mach 2.54 or more.