Level change

[Guest Mik75]

Hi!I am very pleased to read that the release of this groundbreaking addon is finally happening!This will change my FSX experience completely.I have one question concerning the video from Nick of AOA in which he takes a look at the A/P system.I am aware of the fact that he used an early wide beta version to shoot that video (at least that´s what he says in the video), but I noticed that LVL CHG doesn´t work smoothly (climb rate of 7000 fpm) and at one point of the video, the dialed in altitude was even overshooten. Has this been revised for the release version?Otherwise, I am deeply impressed by the pure work of art, PMDG!Greets from Germany,Michael Schmitt

[michal 44]

I would say there is no one iota of evidence that the LVL change doesn't work the same as in real aircraft. And 7000 fpm has nothing to do with smoothness, more with extremely light weight. Only a qualified tester (like Jack C.!) flying it (and not watching AoA video) could render qualified opinion.

[c402_cvs 0]

He does menyion in that video the aircraft is very lightly loaded. FRED

[Guest Mik75]

That´s true! With "not smooth" I meant, that the rate of climb is 7000 fpm and than goes back, alternating a bit and in the end, the target altitude was overshooten. I don´t have any doubt, that PMDG will simulate the whole thing as exact as possible!

[WernerR 0]

I've noticed the NG missing the altitude at level change several times in real life too Up to about 150 or so feet, and then starts a slow descent, and usually enteres alt hold either at the exact altitude, or plus/minus 20-30 ft. Mind you, this is usually when the weight is low, not so much of a problem when you're carrying a full load of passengers.

[rdb 44]

Besides, it's a good idea to climb/descend the last 1000ft below/above cleared level with V/S mode at 1000 fpm or less. Saves you and ATC from filling post TCAS report

[Spin737 102]

A short altitude change (<2,000feet) is usually best accomplished in V/S or VNAV and not in LVL CHG for this very reason.

[Jack_C 1]

Hey guys. EV has done a fantastic job at the level off predictions with the ngx. I can. Not think of a time yet that I have overshot an altitude. In fact i was climbing at 5500 fpm and the level off was fantastic. The VNAV SPD changed to VNAV ALT at 2000 FPM below taget altitude and it leveled off nicely. Coincidentally, I was in a 600 te other day going from cyvr to cylw and in the last part of te climb we hit a wicked mountain wave and reached 5000-6000 feet a minute. Right at FL220 (2000 feet below target altitude) the VNAV ALT engaged just like the NGX did. So just goes to show EV nailed that perfectly.JackColwill

[emvaos 13]

Hi!I am very pleased to read that the release of this groundbreaking addon is finally happening!This will change my FSX experience completely.I have one question concerning the video from Nick of AOA in which he takes a look at the A/P system.I am aware of the fact that he used an early wide beta version to shoot that video (at least that´s what he says in the video), but I noticed that LVL CHG doesn´t work smoothly (climb rate of 7000 fpm) and at one point of the video, the dialed in altitude was even overshooten. Has this been revised for the release version?Otherwise, I am deeply impressed by the pure work of art, PMDG!Greets from Germany,Michael Schmitt

Michael, Some simmers are confused by the pitch to speed mode which is what level change is. Probably because with the exception of very few add ons it is modelled in an...erm... garbage fashion? The AFS (automatic flight system) adjusts pitch to match set target speed (MCP speed for level change and speed intervention and VNAV speed otherwise) against actual speed. The only limitations is the rate of pitch adjustment limited by g-load and max pitch value limited by angle of attack as obtained from the SMYD's (stall management yaw damper system --- two of them). 1000, 3000, 6000, 2345.784 thousand feet per minute is irrelevant. Whatever the local conditions demand. Extreme case scenario : current IAS 300, level at 5000 feet, almost empty plane... Now roll MCP altitude dial to 15000, press level change, roll down MCP Target to 250...Rocket up (but in a very very controlled fashion, we don't want to be spilling pax orange juice all over now do we ?) Key is : is it controlled and...do I get an altitude bust ? You will not in the NGx.

[gman1986 14]

Very nice explanation Mr Vaos. With regards to the op's comment abou the assigned altitude overspill, is that how it would react under it's weight conditions? If so then it means we have to closely monitor our actions even more.

[RPRIEVER 52]

Very nice explanation Mr Vaos. With regards to the op's comment abou the assigned altitude overspill, is that how it would react under it's weight conditions? If so then it means we have to closely monitor our actions even more.

It's not "Mr" Vaos....it's "Dr" Vaos.

[gman1986 14]

It's not "Mr" Vaos....it's "Dr" Vaos.

Oh no you didn't 

[Etai Charit 0]

VS value is indeed irrelevant in terms of climb, but when leveling-off, it is very relevant. There is a method that says that devide the VS value by 3, gives you the how many feet below the desired altitude to start leveling off. Ex: climbing at VS of 3000 FPM to FL180, 3000/3=1000 feet in advance start leveling-off gently, that means at FL170 I'll begin lowring the nose.