Entering VNAV speeds in the CDU

[SierraDelta 1,349]

Interestingly, the 777 manual that I have access to (see below) clearly shows that user inputs to VNAV CLB or DES pages are limited to either CAS or Mach - not both. On the CLB page either CAS or Mach is shown (on LSK L2), but on the DES page both values are shown.It seems that the diplay of either CAS or Mach on the CLB page is governed by an entry in the airline policy file, so I wonder if the whole issue could be airline option dependent?Anyway, below are extracts from the relevant parts of the manual-------------------------------------------------------------------VNAV CLB pagePage TitleThe page title shows the type of climb.

[Guest Sjaako]

And then it goes on saying:The FMC commanded speed is in magenta. Below CAS/Mach transition altitude, CAS is magenta and Mach is white. Above CAS/Mach transition altitude, Mach is magenta and CAS is white.So this would mean both values are displayed leading me to believe you can change them both ie CAS/Mach entry.CheerioSjaako

[Guest Sjaako]

Hi,Just had a look at the Cathay 777 video. This shows the VNAV CLB page with both numbers ie. CAS/Mach.Maybe it is airline specific.Can't tell you more till I get my hands on the real deal Friday.Cheerio

[SierraDelta 1,349]

>And then it goes on saying:>>The FMC commanded speed is in magenta. Below CAS/Mach>transition altitude, CAS is magenta and Mach is white. Above>CAS/Mach transition altitude, Mach is magenta and CAS is>white.>>So this would mean both values are displayed leading me to>believe you can change them both ie CAS/Mach entry.>Sjaako,You're right, I didn't cut'n'paste the last bits, but they are indeed as you described above. That being said, the Cathay video (which I don't have) definitely does not correlate with the information from my Continental Manual.I'll see if I can find some stuff on airliners.net Found this one: http://www.airliners.net/open.file/0238090/L/Difficult to read but it seems that the captain is on ACT ECON CLB and there are indeed 2 values indicated, I guess its magenta CAS and white Mach in this case. Let us know after Friday.Cheers,S

[Guest Sjaako]

Hi,Well just got back and the story goes as follows:All 3 entry methods worked i.e.-CAS-Mach-CAS/MachThe only thing different from other boeing aircraft I've flown is that when you enter just an CAS OR Mach, it only shows that one number. Cheerio,Sjaako

[Guest tyrant]

Thanks for all the research there. Can this maybe added to the list of bugs/fixes for the patch. it would be nice to have as close to life as possible.Jason

[Guest skybo120]

I have noticed the AP disconnect problem as well. In the real A/C, you click the AP Disconnect button twice on the yoke and it cancels all EICAS messages and aural warnings related to the disconnect. Is this just an error in the PSS software that we are unable to cancel them out? It doesnt bother me at all, its just sort of odd.In reference to the VNAV climb speeds, I had a discussion with my dad about it since hes a 777 FO for COA. I asked him if it was possible to change the VNAV speeds on the climb page. He said you could, but he doesnt understand why you would want to. He said that if you needed to change your climb speed, which is mainly due to ATC instructions, you would just do it in the airspeed window on the CDU. Otherwise, the VNAV speeds are calculated by the cost index you put in during preflight. So I guess my conclusion would be if you needed to increase/decrease your speed during climb, take the A/C out of VNAV and put the desired speed in the CDU window, then click Flight Level Change or FLCH. It is my understanding however, that pilots rarely use FLCH or VS (vertical speed). I hope this answers your question.Brian

[Guest Sjaako]

Hi,Well as you said in the climb it is not all that usefull, in the descent however all the more. This is where it is used most in real life. Also when you update your descent speed it will give you new vertical profile information. This comes in usefull when on an atc resriction and you fly in FLCH or V/S.You can fly in VNAV as a vertical mode and open the MCP SPEED WINDOW. this will allow you to directly control the speed to your liking.I use V/S all the time.... Today there is so much traffic it really helps to use V/S when you approach your cleared level and try not to scare the guy/girl 1000ft above/below you with a TCAS RA.Also a very valid reason to change your climb speed is turbulence, but this is mainly done through the MCP window.CheerioSjaako

[Johan_Dees 84]

heheh, an old and bold 747 pilot told me never to trust the flch. In the real a/c he said (NWA) it to wild, he always used the V/S for climbs and decends.I think.. just think.. that we want it to be to perfect, while the real one isnt also.JohanPS: nothing todo with the speeds.. btw..A LITTLE LESS CONVERSATION, AND A LITTLE MORE ACTION PLEASE!HELP:http://support.microsoft.com/?kbid=238882