V-SPEEDS DELETED after APPROACH speeds selected

[richjb]

Beginning with ver 1.5.2, I have been getting frequent V-SPEEDS DELETED CDU messages, and finding that the VREF, VAC, and VFTO speeds have reverted to white instead of pink.  They are also not showing the PFD airspeed tape.  

Today, while flying a circuit around KICT's ILS 19L, I had to reset the V-speeds about 6 times including twice on final approach.  I noticed this on previous flights after upgrading to 1.5.2.  No idea why.  I didn't change any performance parameters.  I did extend the final approach course on the ILS 19L, but that should have affected it. 

This was not an issue with ver. 1.4.x but did begin with ver. 1.5.2.

Thanks for you assistance!

Rich Boll

 

[Pils]

I can’t find anything in the change log that sounds like it would touch the V-speeds. Could you perhaps try your flights with a fresh new airframe?

[Pils]

If it only happens when flying patterns could it be this?

[richjb]

That could be the reason!   Good systems modeling! :-) 

Rich

[richjb]

Hi Pils,

I say that it could be, but I don't recall it being as a frequent of an occurrence with1.4.x.  

If you provide me the page reference for above, I'll try to dig further into it. 

thanks,

Rich

[Pils]

12 minutes ago, richjb said:

f you provide me the page reference for above, I'll try to dig further into it. 

Search in the FMS manual. I’m not sure what version you have.

12 minutes ago, richjb said:

I say that it could be, but I don't recall it being as a frequent of an occurrence with1.4.x.

I don’t see it being new behaviour. But maybe the way you set up orig/dest changed?

[richjb]

17 hours ago, Pils said:

Search in the FMS manual. I’m not sure what version you have.

I don’t see it being new behaviour. But maybe the way you set up orig/dest changed?

I did a short test flight from KICT to KHUT.  I noticed there.  I flew a second flight from KPDX to KMFR, but did not see it on that flight.  Yesterday, I did a V1 cut at KICT (see my post on that issue) then did an immediate return to KICT.  I saw it six times on that flight including at least twice on final approach inside the FAF.  I don't think that should happen. 

I'll check my manuals.  I have set of 650 books for 2018 period now. 

Thanks again for your help!

Rich

[richjb]

On 4/9/2022 at 4:02 PM, Pils said:

Search in the FMS manual. I’m not sure what version you have.

I don’t see it being new behaviour. But maybe the way you set up orig/dest changed?

Hi Pils,

So, I did find the reference in the CL650 FMS book....and in the CL300/350 FMS book! 

Let me see what I can find about this behavior from my list of gurus. 

Rich 

[richjb]

Hi Pils,

I contacted my retired Collins customer liaison/training pilot about this behavior. He gave me a good explanation of how this works. When you enter the ORIG and DEST airports, you create two DEP/ARR page selection "silos", one for the ORIG airport and one for the DEST airport.  On the ground, or airborne within 50 miles of the ORIG or less than 1/2 way between the ORIG and DEST airports if the distance between the two is less than 100 miles, the first press of the DEP/ARR key bring up the DEPART page (if on ground) or the ARRIVALS page (if airborne) for the ORIG airport.  The second press brings up the DEP/ARR INDEX Page, where you select DEPARTURE or ARRIVAL page for either the ORIG (first option) or the DEST (second option):

 

In the air, the first press of the DEP/ARR button bring up the ARRIVALS for the ORIG airport is less than 50 miles or less than 1/2 of the distance between the two airports if they are separated by less than 100 miles.  More than 50 miles or more than 1/2 of the distance between the two airports, it brings up the ARRIVALS page for the DEST airport. These are the two "silos" ARRIVAL options that can be selected once airborne.  The engineer's intent was that in an emergency return the departure airport, the pilot will want quick access to the approaches available at the departure airport, which is why the first key press of the DEP/ARR key brings up the arrivals for the ORIG airport. 

The closer the two airports are together, the greater the chance the airport selection can confusing.  For example, a short flight from Wichita - Eisenhower (KICT) to Wichita - Jabarra (KAAO), separated by about 10 miles.  After takeoff and while getting radar vectors to Jabarra, if you load the approach and complete the landing data on the APPROACH Performance page, but then for whatever reason start getting vectors back to towards KICT and the distance to KICT becomes closer than KAAO, the FMS can think that you're now trying to return to KICT, the FMS has moved back to the ORIG silo and the APPROACH Performance page has moved back to the ORIG airport and as result has dropped the V-Speeds and performance data.  If you look on the APPROACH REF page of the FMS, there are two airports - the ORIG and DEST:

The FMS has gone back to the ORIG airport in this case and dropped the V-Speeds. 

It gets more confusing when you're in a round-robin training mode, for example the ORIG and DEST airports are both "KICT".  in the air If you press the DEP/ARR key, the FMS brings up the ARRIVAL page for the ORIG airport, KICT.  If you load the approach and then complete the APPROACH REF page based on the ORIG airport ARRIVAL loaded in the FMS, as you fly downwind for the return approach, at some point the FMS will think it's more than 1/2 way away from the ORIG airport and switch to the DEST airport's silo, and its APPROACH REF page is blank because you have not entered any data for this runway.   The FLT PLN and LEGS page still show the approach you selected using the ORIG airport, but the Performance page has switch from the ORIG airport to the DEST airport. 

If you press the DEP/ARR key twice to bring up the DEP/ARR INDEX page, select the approach from the DEST airport (i.e., the second airport in the list) AND....you select the DEST airport on the APPROACH REF page (i.e. the second airport option - in the example above that shows KMSP/KLAX, select "KLAX") you are less likely to have the V-Speeds dumped.  He says it's not impossible, but much less likely.  Again, if you turn back around and it thinks you're going back to the ORIG airport, the FMS can switch back to the ORIG airport performance page. 

The behavior I was seeing in HS CL650 did initially mimic this behavior, and it's what I have seen in the Level D CL300 simulators when we're doing circuit training, i.e. multiple back to back approaches.  What I was also seeing in HS CL650 was the FMS drop the V-speeds multiple times on final.  My contact says that should not happen.  As long as you're in one branch or "silo" of the ORIG or DEST airport, the V-Speeds should not drop unless you switch silos, which is not likely as your final approach and you've set one or the other branch/silo - the ORIG or DEST.

Please let me know if this makes sense? 

Thanks!

Rich Boll