Error in Mach vs. TAS on Pilot airspeed indicator

[JRBarrett 3,034]

There is a disparity between the outer Mach scale on the pilot’s airspeed indicator vs. the copilot’s indicator. I am currently in level flight at FL390, showing a TAS of 433 knots with a TAT temperature of -33C. This is verified on the DALT/TAS/Winds page of the GTN 750

TAS of 433 knots at TAT of -33C equates to Mach 0.753, and that is exactly the Mach speed shown on the copilot airspeed indicator. The pilot indicator shows Mach 0.80. The indicated airspeed is exactly the same on both instruments, it is only the Mach scale which is different, with the copilot airspeed indicator being the correct one.

Jim Barrett

 

[Pat Mussotte 92]

You are absolutely right Jim, I confirm!

 

[scottb613 1,186]

3 hours ago, JRBarrett said:

Jim Barrett

Who is this masked man ?!?!

LOL - nice - what an asset...

Regards,
Scott

[ark 1,288]

4 hours ago, scottb613 said:

Who is this masked man ?!?!

 

 

The Lone Ranger Falcon of the sky!      😃

Al

[Flysimware 647]

Thanks for noticing. I do remember updating the accuracy of the mach scale due to that fact this extremely hard to code and animate. So i was happy with the new scale compared to the L35A. And i now realize the pilot instrument must have got updated at a later time in the project and got reverted back tot he wrong version. Because i would have calibrated from pilots seat. And in fact the copilot's gauge is the one that has the new accuracy.

Thanks! 

Edited November 20, 2018 by Flysimware

[JRBarrett 3,034]

2 minutes ago, Flysimware said:

Thanks for noticing. I do remember updating the accuracy of the mach scale due to that fact this extremely hard to code and animate. So i was happy with the new scale compared to the L35A. And i now realize the pilot instrument must have got updated at a later time in the project and got reverted back tot he wrong version. Because i would have calibrated from pilots seat. And in fact the copilot's gauge is the one that has the new accuracy.

Thanks! 

You’re welcome!