RocketmanAL Posted October 21, 2023 Posted October 21, 2023 The Mach number portion of the speedometer appears to be off. It is showing a higher Mach number than the aircraft is actually flying according to TAS. Steps to replicate: Add SU-25T and set it to start at M= .8, 20kft, TAS should be 496 kts. Jumping in the plane it shows the plane at M= .92. Indicated M=.8 occurs around 432 kts.
Mike_Romeo Posted October 21, 2023 Posted October 21, 2023 1 hour ago, RocketmanAL said: The Mach number portion of the speedometer appears to be off. It is showing a higher Mach number than the aircraft is actually flying according to TAS. Steps to replicate: Add SU-25T and set it to start at M= .8, 20kft, TAS should be 496 kts. Jumping in the plane it shows the plane at M= .92. Indicated M=.8 occurs around 432 kts. Mach speed changes with air temperature, air pressure and humidity too. I hope you have taken these into account too. My skins
razo+r Posted October 21, 2023 Posted October 21, 2023 19 minutes ago, Mike_Romeo said: Mach speed changes with air temperature, air pressure and humidity too. I hope you have taken these into account too. I tried at ISA atmo and saw the same.
RocketmanAL Posted October 22, 2023 Author Posted October 22, 2023 4 hours ago, Mike_Romeo said: Mach speed changes with air temperature, air pressure and humidity too. I hope you have taken these into account too. I checked multiple different aircraft as part of testing I'm doing. Same altitude, same speed, same mission. The SU-25T was the only one to have a different TAS at M= .8.
Solution Skuva Posted October 22, 2023 Solution Posted October 22, 2023 (edited) I think the confusion is that the inside numbers on the 25's indicator are not Mach. The indicator on the Su-25 (A and T) gives IAS and TAS While the indicator on Su-27/33 gives IAS and Mach Edited October 22, 2023 by Skuva 3
Ironhand Posted October 23, 2023 Posted October 23, 2023 (edited) On 10/21/2023 at 9:33 PM, RocketmanAL said: I checked multiple different aircraft as part of testing I'm doing. Same altitude, same speed, same mission. The SU-25T was the only one to have a different TAS at M= .8. Just curious. Where are you getting the Mach number from? Neither the Su-25 nor the Su-25T has a Mach meter. If I start at 20,000 ft in either the Su-25T or the Su-27 with the Mach set to 0.8 in the ME, I get identical TAS numbers. Mach Test.miz Edited October 23, 2023 by Ironhand Added: "in the ME" for clarity 2 YouTube Channel: https://www.youtube.com/channel/UCU1...CR6IZ7crfdZxDg _____ Win 11 Pro x64, Asrock Z790 Steel Legend MoBo, Intel i7-13700K, MSI RKT 4070 Super 12GB, Corsair Dominator DDR5 RAM 32GB.
RocketmanAL Posted October 23, 2023 Author Posted October 23, 2023 14 hours ago, Skuva said: I think the confusion is that the inside numbers on the 25's indicator are not Mach. Ah, that would be the answer! Thanks for the clarification.
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