Doubts about aircraft speeds

Hello, I would like to contact you @Kyle_D to clarify some doubts about the speeds of the aircraft while I was participating in a Dan event in Expert Server Beta, when I reached less than 28000 feet the Mach speed disappeared and with normal speed, and even so I got nervous when he told me it will be reported, please. With pleasure so as not to have any more doubts, Thank you


At 28000ft it switches between the two - so if you climb through 28000 it will go from IAS to MACH and if you descend through 28000 it will go from MACH to IAS.

IAS = Indicated Air Speed (the speed on the left hand bar of the HUD)

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Heya as mentioned above IAS appears and Mach “disappears” under 28K feet, in this case i issued the maintain Mach 0.78 command upon entry of the Oakland airspace.

it was all good until in the descend i noticed that you slowed down, this resulted in the separation being a bit off, in busy events as this one we trust that all users know and follow the instructions properly, hence when I noticed a change in speeds I immediately warned you to avoid further backlash/ get your attention to immediately change back to the instructed speed.

Your Mach speed is always present on the left side of your screen underneath your IAS, you can use this for reference in case you are descending underneath the 28k mark. In this case keeping mach 0.78 throughout the descend would do the job, the autopilot automatically changes it to knots when the crossover point is reached so there’s no need to touch it, unless of course given a different speed instruction later on.

I hope this answered all your questions, I noticed you opened a dm, you can always pop a message if you have any follow up questions. Better safe then sorry! :)

Happy holidays

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Oh I made a mistake slowing down while descending but now I understand the mach is the same as the IAS, I was quite confused thinking the speed would increase without me moving the throttle that’s why I slow down, Lesson learned and no it will happen again in my next flights, thanks!!

Have a Merry Christmas and a Happy New Year!!

Hey man! It’s all good! We all learn, bear in mind that IAS is the same as Mach when you have your autopilot on, so if someone tells you to stick to 0.78 just put it to 0.78 and don’t move it, even when the auto pilot displays it in knots after a while.

I’m glad you asked, it’s always way better to ask around, questions are always welcome!

Hoping to see you in the skies soon!


Would recommend contacting controllers privately in the future since community input might not necessarily always be the best option sometimes. Glad to hear things between Kyle and you are cleared up, see you in the skies! :)

If it is more general, feel free to post a topic such as this, and us controllers would be happy to answer. Always encouraged to ask questions whenever you are in doubt of operations or ES overall!

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