Framer, I am curious as to why you would ask opinions and then discount them
Hi Kirk. Sorry if my simple "Nope" seemed a little dismissive. Earlier in the thread endofeng said that it may be something to do with avoiding levelling in VNAV, I responded to that with
Nothing to do with levelling in VNAV
( I can see why you thought that though.)
so when the idea was put up a second time my response was simply "Nope" because I felt like I had been clear about that. Again, I apologise if it seemed rude or dismissive.
Here's a scenario, you depart. select VNAV and then are told to "Climb Now" fl XXX or ALT XX, how are you going to do this.?. ATC expect the climb to start pronto, and getting the PNF to dig in the FMC and remove the altitude constraints and then remain in VNAV is not a good idea. I dont want to get into a debate about thrust modes etc or FMAs.. just an opinion on how you would achieve this without using LVL Change or VS,
If I was in that exact scenario I would say something along the lines of "Level Change .......kts " and continue to follow the flight directors. I'm not sure why you think I wouldn't use Level change.... I wouldn't use V/s going uphill but thats just my preference (unless of course there was likelyhood of a TA)....anyway, this thread is not about that..........
Jolly,
Also on the Classic selecting LVL CHG automatically puts you in the N1 mode
See this is where I start to come unstuck....it is already in N1 mode from the moment you pushed N1 at acceleration altitude. The A/T is commanding climb thrust in N1 mode . If you then go and push Level change it will still say N1 and it will still command climb thrust. The only thing that will change is that the pitch mode will go from TOGA to MCP speed.....now my problem with that is that they behave in an identical manner as far as I can see, if you bug up to 250 or 280 while pitch mode is in TOGA it pitches for that speed, it will stay in it and pitch for whatever speed you want until you select another mode (ie VNAV or MCP speed by putting the a/p in or selecting Level Change. So maybe my question should be "what is the difference between TOGA and mcp speed pitch modes when clean and above acceleration height?.
Anyway, thanks agaiin for your replies, still not sure if there is a benefit to doing it
.....more thinking required.