VNAV issue at ENVA SID TGA1X

[Michael Moe 496]

Just wanted to share an experience this night regarding the VNAV in the NGX behaving bad just before VA400 in the SID after flaps up procedures and speed. 

 

I was given directly FL300 from ATC and used FS2CREW to set the flightlevel and commanding VNAV then VNAV PATH apeared setting about 4000-6000 feet per minut with A/T on but the speed would drop way below flaps up speed and very close to stall-speed being in the yellow tape when i hit the V/S to 1400 feet climb and gain back some control.

 

I cant recall VNAV behaving this bad but the rest of the flight was fine.

 

Thanks

 

Michael

[g_precentralis 191]

That behavior is not related to that SID at all.

[machine2035 176]

Was there any altitude restrictions on the SID (I have just looked the plate up quickly and couldn't see any).

 

If there wasn't, I believe you should of had VNAV SPD annunciated in the FMA along with N1 in your A/T FMA (Left-most part of the FMA).

 

Do you happen to remember what your A/T mode was in? While it shouldn't happen, I have a sneaking suspicion it might of been in ARM mode, with your physical throttle being idled, and therefore the throttle in the sim commanding a low N1.

[Michael Moe 496]

I believe everything was normal in the PFD and MCP and Throttle was where it should be. but i will come back if i can reproduce it.

 

If i hit FLCH and dial the speed for flapsup speed PFD should show MCPspeed just before the VNAV thing. I remember looking at the engines and they where around 94

[joolsd 10]

Just wanted to share an experience this night regarding the VNAV in the NGX behaving bad just before VA400 in the SID after flaps up procedures and speed. 

 

I was given directly FL300 from ATC and used FS2CREW to set the flightlevel and commanding VNAV then VNAV PATH apeared setting about 4000-6000 feet per minut with A/T on but the speed would drop way below flaps up speed and very close to stall-speed being in the yellow tape when i hit the V/S to 1400 feet climb and gain back some control.

 

I cant recall VNAV behaving this bad but the rest of the flight was fine.

 

 

Are you sure the CMD A is on?  I use FS2Crew, and sometimes I find that the F/O, for some reason doesn't always engage the auto pilot.  I made that exact mistake tonight.  So I was pressing all the MCP modes, thinking it A/P was on, wondering why nothing was working, and assuming that there is a bug in the software. Was the green CMD mode visible in the PFD, and not just F/D?

 

I think I'm going to make a rule that I select CMD A myself, I don't trust the robot next to me.

[Michael Moe 496]

It was engage because the airplane was rolling on a LNAV track . The problem was showing VNAVPATH and not correctly VNAVspeed. I was at flapsup speed when i engage the VNAV. Will try again

[g_precentralis 191]

Every plane has its own quirks. You spotted wrong mode at FMA? Click, click... click, click. Why would you wait for speed to fall down to yellow area? Why would you treat serious condition with another AP mode?

 

I know we are kinda boring, but you really should watch Children of Magenta video again.

http://www.youtube.com/watch?v=h3kREPMzMLk

[Lek767 37]

There should be a forum drinking game that has us empty the bottle every time someone posts "Children of Magenta". :lol:  (Don't get me wrong; it's a great video and anyone should see it and most definitely live by it...)