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What does MPH mean


fitness88
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Performance F-15C

 

Maximum speed:

High altitude: Mach 2.5+ (1,650+ mph, 2,665+ km/h)

Low altitude: Mach 1.2 (900 mph, 1,450 km/h)

http://www.digitalcombatsimulator.com/en/products/eagle/

 

What exactly do these speeds mean? I've seen speeds of 850+kts [978 mph] but nothing close to 1650+ mph at any altitude, is this IA speed or True speed or Ground speed that is being mentioned?

 

Thank you.

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miles per hour

 

To convert to knots you can go to Google.

To whom it may concern,

I am an idiot, unfortunately for the world, I have a internet connection and a fondness for beer....apologies for that.

Thank you for you patience.

 

 

Many people don't want the truth, they want constant reassurance that whatever misconception/fallacies they believe in are true..

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I don't know thr exact numbers but they are just conversions. Maximum speed of the eagle is at high altitudes 2.5x the speed of sound. This would mean at sea level, where speed of sound is ~330m/s, 2.5 Mach are equal to 1,650 miles per hour or 2,665 kilometers per hour.

 

Interestingly the Mach Number is always IAS as it is bound to fluid dynamics such as temperature, density et cetera. The latter numbers are ground speed at standard conditions, just for better comparison.

 

That's why Felix Baumgartner could break the sound barrier in free fall. Because air was less dense, resulting in less drag and due to lower speed of sound at extreme altitude, he had to reach a lower total velocity compared to ground speed.

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I don't know thr exact numbers but they are just conversions. Maximum speed of the eagle is at high altitudes 2.5x the speed of sound. This would mean at sea level, where speed of sound is ~330m/s, 2.5 Mach are equal to 1,650 miles per hour or 2,665 kilometers per hour.

 

Interestingly the Mach Number is always IAS as it is bound to fluid dynamics such as temperature, density et cetera. The latter numbers are ground speed at standard conditions, just for better comparison.

 

That's why Felix Baumgartner could break the sound barrier in free fall. Because air was less dense, resulting in less drag and due to lower speed of sound at extreme altitude, he had to reach a lower total velocity compared to ground speed.

 

How come you never see these speeds indicated in the cockpit in either IA speed or True speed or Ground speed?

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I don't know thr exact numbers but they are just conversions. Maximum speed of the eagle is at high altitudes 2.5x the speed of sound. This would mean at sea level, where speed of sound is ~330m/s, 2.5 Mach are equal to 1,650 miles per hour or 2,665 kilometers per hour.

The speed of sound at sea level is not relevant here. 1650 ÷ 2.5 = 660, which is the speed (in MPH) of sound at 35,000 feet.

How come you never see these speeds indicated in the cockpit in either IA speed or True speed or Ground speed?

The military uses knots, not MPH. At 35,000 feet, the speed of sound is 574 knots. So, Mach 2.5 = 1650 MPH = 1435 knots.

 

This is a number that you certainly can see in the Eagle's cockpit. In the lower left corner of the VSD, you'll see your ground speed. In the lower right, your true airspeed. I just took the Eagle up to 35,000. At Mach 2.500, my ground speed and my true airspeed both showed 1440 knots.

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The speed of sound at sea level is not relevant here. 1650 ÷ 2.5 = 660, which is the speed (in MPH) of sound at 35,000 feet.

 

The military uses knots, not MPH. At 35,000 feet, the speed of sound is 574 knots. So, Mach 2.5 = 1650 MPH = 1435 knots.

 

This is a number that you certainly can see in the Eagle's cockpit. In the lower left corner of the VSD, you'll see your ground speed. In the lower right, your true airspeed. I just took the Eagle up to 35,000. At Mach 2.500, my ground speed and my true airspeed both showed 1440 knots.

 

Just tested and you are correct.

Thank you for your response.

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Im at 35k feet as we speak and just reached my fastest speed so far. My true airspeed on the VSD tells me Im going 1100knots but I cant get any faster. This is my fastest speed Ive reached so far, dumped all external fuel tanks.. I dont get how you can reach 1400 knots.

 

And how its this something you would use e.g online.. I mean, it burns alot of fuel!

 

As for now, Im flying with unlimited fuel with indestructable and so on just to get to know all the different systems and so on, will try to reach these speeds with limited fuel later on and see how little time it will take to run me dry.. It sure wont be the first time Im running out of fuel! :)

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Im at 35k feet as we speak and just reached my fastest speed so far. My true airspeed on the VSD tells me Im going 1100knots but I cant get any faster. This is my fastest speed Ive reached so far, dumped all external fuel tanks.. I dont get how you can reach 1400 knots.

 

And how its this something you would use e.g online.. I mean, it burns alot of fuel!

 

As for now, Im flying with unlimited fuel with indestructable and so on just to get to know all the different systems and so on, will try to reach these speeds with limited fuel later on and see how little time it will take to run me dry.. It sure wont be the first time Im running out of fuel! :)

 

More fuel is more weight, which means more drag. Your weapons also contribute to drag, so even if you drop all tanks, you can get a further drag reduction by jettisoning weapons. I'm not sure if this is right, but I don't think the F-15 can reach M 2.5 with weapons under the wings. You can only have the 4 semi conformal AMRAAM/Sparrow.

 

And yes, getting to max speed will use a lot of fuel. You wouldn't try to get there unless you were flying an intercept.

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