Bug or something else?

[craig_read 43]

Watching the Airline2sim cadet training for the 777, in video 14 at around 1 hour 24 minutes they're starting their approach to the field.  The aircraft is programmed to maintain 170/1500 at the waypoint PERLY.  This was setup at 28 minutes in the video.  However when they set VNAV when approaching PERLY it accelerates to 225, but shouldn't it have maintained 170?

 

I'm not saying this is a bug, it's more a question because the guy doing these videos is a 777 pilot with many hours and he seemed quite surprised at this behaviour saying in the video "it should gone to 170"... "It shouldn't have done that..."  Could anyone at PMDG comment on this? 

 

Cheers

 

Craig

[Airline2Sim 489]

I should just jump in here to say that no-one at PMDG has seen how we set up this approach so an answer might not be easy to reach without watching it. Also we found a few things in the Q400 that were different to the real one - speed limits in the VNAV page mangling the TOD point etc  - that we just put down to modelling differences or the sim itself.

 

We did ask our around our pilot group (5 different 777 guys) about why it would not maintain a pilot entered waypoint speed when VNAV is pushed and they all just shrugged and said 'hmmm, well, 777 VNAV' so by the sounds of it none of them lay too much faith in the real one. I'd be more than happy to make the vid available to anyone at PMDG who wants to take a look, as this question has cropped up a few times.