Is Mach 1 incorrect in flight?

I did a few tests in flight with an F/A-18 to see what speed Mach 1 really is.
If you don’t know already, Mach 1 is equivalent to the speed of sound, or known as supersonic speed. Mach 1 is also equivalent to 666.739 knots or 767.269 mph.
My first test I did with 10 mph winds, plus 3 mph wind gusts.
When I climbed, I checked the M meter while in cockpit view. This is what represents Mach.
I thought I hit Mach 1 after passing what appeared to be 545 knots. However, this is WAY OFF. 545 knots are equivalent to Mach 0.817. See the difference?
The second test I did without any winds. (Also forgot to mention, both times I took off at KORD, Chicago O’Hare International.)
When I continued to climb, I thought I hit Mach 1 after hitting at least 585 knots. Except it’s still really far off.
585 knots equal Mach 0.887.
I thought this would be the end of my test, but I did another test in a different game, Air Fighters By RORTOS SRL.
I used the same jet, same airport, and no winds. What I found was way more closer.
When I heard the BOOM (this also means you hit Mach 1, if you hear a BOOM), I knew I hit Mach 1, But it was still off!
It was way closer than the Infinite Flight tests, 642 knots was when I heard that BOOM.
This equals in Mach, 0.962.
If you have any other tests or any other experiments that can prove me wrong, please do comment, I’d love to hear it.
In the meantime, remember that this is just a theory I have, so it may not be NEAR correct.


Extreme landings is inaccurate.

The speed of sound differs (goes down relative to as you go up in altitude with the air getting thinner and colder.


Mach 1 is not incorrect, Mach 1 is dependent on the density and temperature of the air surrounding the aircraft, and therefore altitude. Look at your ground speed indicator and it should show around 666 knots.


Mach is relative. Mach depends on air density, Altitude and temperature. You can’t recreate it 100% precisely


You can provided that:

  1. Test conducted at sea level
  2. Temperature at 20˚C

The lower you go the closer it is the higher you go it gets further away on ias

What people are trying to say is the only indications in IF are ground speed and indicated air speed (IAS). IAS becomes inaccurate at a certain altitude (crossover altitude) when air density is lower and more difficult to measure directly with a pitot tube. Therefore, Mach number is used.

Since speed of sound is not constant (changes with temperature), you cannot simply say that mach1=666kts.


Local speed of sound is temperature dependant. That is why it’s called local as temperature changes across areas. To calculate mach 1 speed use the following equation:

Mach 1.0 in kts = 39 x square root temperature in kelvin.


The devil has arrived💩👹

ok, back on topic:)

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