[PFD] IAS/Mach automatic switch over

[CRJay 429]

While some work has already improved the automatic switchover between IAS and Mach at 31600ft, it still needs a final touch.
 

At the moment it will switch regardless of which mode you are in. So if you switch to Mach before 31600ft, it will reset your Mach speed bug again at 31600ft. For example, I already had M.74 selected around FL280 and while leveling off at FL320 in VS mode, the speed bug jumped up to M.80 while passing through FL316 as my speed increased during level off. 
 

Or if you descent and you set IAS mode before descending through 31600ft it will reset the speed bug to whatever your current IAS is when passing through 31600ft. 
 

This should not happen. If you are already in the mode that the automatic switch would put you in, it should not do anything and just keep what you have set manually. A bit of relatively simple “if this then that” logic should fix this I imagine. 
 

Short video attached for demonstration. IAS mode selected early above FL316. You can see 1/2 bank turn off but speed bug stays where I put it. 

Please login to view this video.

[GEK_the_Reaper 233]

@CRJay this is already under investigation and on our tracking list. One of the pilots told us (if I remember corectly) that the switch has to be done manualy because of (I don't remeber why).

[CRJay 429]

That reads like it is under investigation to not have it automatically change?

 

It does not HAVE to be done manually, it will absolutely do it automatically at 31600ft. You can set CLB 280 and lean back to watch the plane switch to ~M.77 at 31600ft and happily climb to cruise. But it should only change if you are not in the correct mode already, eg. Mach above 31600ft and IAS below. Right now it just seems to reset the bug to the current speed at the moment of passing 31600ft, regardless of what was already set. That's the only thing left that is not like on the real plane about this whole little subsystem :P. Minor things, but the finishing touch.

[GEK_the_Reaper 233]

vor 16 Stunden , CRJay sagte:

That reads like it is under investigation to not have it automatically change?

No. We are investing this because the VNAV data entered into the FMS for CLB (e.g. 290/.74) does not affect the transition nor SPD in CLB (it should transition from IAS to Mach acc to the settings in FMS ---and it is not doing it).

So yeah...it is on the watch list for fine tuning.

[CRJay 429]

3 hours ago, GEK_the_Reaper said:

No. We are investing this because the VNAV data entered into the FMS for CLB (e.g. 290/.74) does not affect the transition nor SPD in CLB (it should transition from IAS to Mach acc to the settings in FMS ---and it is not doing it).

So yeah...it is on the watch list for fine tuning.

It should NOT switch according to the FMS. That was what it did before (and then again at 31600ft) which was luckily fixed after a previous topic on this. 
 

It ONLY switches automatically at 31600ft, not according to whatever is set in the FMS. The values in the FMS VNAV setup are used for calculations like time remaining etc. 

[GEK_the_Reaper 233]

@CRJay roger that, I think I understood your first post now. I will raise the Q in the team.

 

It was confusing because IIRC, a RLP told us that the VNAV values should be taken into consideration for the switch. I will check again in our BETA team.

[CRJay 429]

Yeah, it is also not the easiest thing to describe, haha .