I’ve been very impressed with flying the Citation Longitude (and others) in MSFS after the AAU update.
I noticed that the new VNAV Climb page now has different climb modes (High Speed, Cruise, Maximum Rate). I see that the differences in speeds for each mode are listed in the Garmin. I was wondering if any setting is preferable or recommended over the others. I can’t seem to find any discussions about this in the forum or elsewhere. Thanks!
Max Rate is typically only used if the STAR has a particularly steep climb gradient required (typical of mountainous areas) or if ATC asks for “best rate”
Cruise Climb is a relatively optimal blend of forward speed and climb rate, and generally results in the least fuel used by the time you arrive at the first fix after top of climb.
High Speed climb is preferred by pilots who just want to get moving (or who have passengers who pay by the hour, not for fuel directly…) and gets you the best forward speed while maintaining a healthy climb rate even while full.
Typically, cruise climb or high speed is what you’ll want.
Thanks very much for your answer! My plane seemed to be on Max Rate by default, which I guess explains why the plane wanted to climb at 6000-7000 per minute 
The good news is it remembers what you select, so my plane is always ready for high speed climb unless I tell it otherwise.
It’s not clear to me whether it is required to enable VNAV and FLC mode during climb or is just VNAV mode sufficient?
For a climb, vnav is not sufficient. Vnav will stop climb according to altitude restrictions but you have to tell it how you want it to climb in the first place.
You don’t technically have to use FLC it is just the recommended. You can also use v/s or pitch
(sorry, thought I was replying to a different post).
Can you help me with the VNAV on the AAU1 Cessna Longitude. I cannot get it to climb or descend even after I have put all the altitudes into each waypoint, the airspeed does follow what I enter. The PFD has FMS on, VNAV is active, AP is on, NAV is on as well as FD.
You still have to select a climb mode
Selecting just vnav will stop it climbing at specific altitudes (as restricted in your flight plan / departure) and will resume previous climb mode once past the restriction, but you still have to select a vertical mode (FLC is the default).
So, assuming you have a “climb via the sid” and the sid is entered correctly:
Takeoff (TO/TO/TO should be annunciated). Positive rate, gear comes up, once established and clear of obstacles, engage VNAV, FLC, and HDG/NAV as appropriate. At this point the auto throttle will move to climb power, and the flight directors will start to direct you into a FLC based climb. You should see VFLC annunciated green and I believe VASEL annunciated white.
You can turn on the autopilot or hand fly at this point as you see fit, but the flight director will give you what you need.
There is some debate about FLC vs VS for climb. I’m of the very strong opinion to use FLC. In the G5000 cockpit you can tell it what speed (or let the FMS speed control apply) and it will pitch for that speed and hold it, so you are not at risk of underspeed / stall. With VS for climb, you can easily set that too high, to a vertical speed the aircraft can’t maintain. Autopilot won’t care, and will keep pitching up to try to maintain that vertical speed.
So the general rule is FLC for climb, VS / VPATH for descent.
Thank you for your help, I finally got it to work.
I agree with the FLC BUT it used to work perfectly. Now after this last update the plane climbs at 3000 to 9500 fpm regardless what the flc is set at, blows thru the assigned alt. and overpowers the auto throttle so the plane stalls. I have not changed anything that i am aware of. Any ideas would be greatly appreciated, thanks Rick
Same issue for me last night!
I think it is related to the auto throttle. Make sure it is not bound to a control button and just use the button in the plane. Hope that helps.
AT Arm should work fine - as long as you get into FLC and have speeds set to Auto. If your speeds are on manual or somethings wrong with your FMS speeds, then the FLC mode might hold VY all the way up which is way too steep for a comfortable level off.
Also verify that the auto throttle brought the throttles to climb mode and not still in to/ga setting.
I fly the Longitude on Xbox quite a bit, and below FL200 I use Vertical Speed mode just because I want to see the scenery a bit longer and control the rate of climb at a more leisurely pace. The Longitude has amazing pressurization which is how it can climb so quickly without too much passenger discomfort, but 7K feet per minute is for people in more of a hurry than me.
The plane takes off in, well, Take Off mode (full thrust) and you have to press either VS or FLC to put it in to Climb Mode, usually after 1000 or 1500 feet. I believe you are not supposed to leave it in TO mode for more than a few minutes or it ruins the engines over time. Pressing VS or FLC just changes modes, even if you are still hand flying - AP does not have to be on.
Here is my procedure, if it helps anyone else:
As for the VNAV climb modes, I leave it in High Speed Climb, which seems to work best. Rate of climb is only slightly slower at high altitudes than Max Rate climb - with the benefit that the plane doesn’t slow down as much and then have to speed up again.