Hello, I'm currently doing a flight with the B738, and, my target altitude is FL380 with a VS of 1800 FPM, everything is fine, not until, the plane pitches up too high in random times (which is unexpected), and the elevator pitch trim is in around 20 degrees (if degrees is right, but this is the number I see in the elevator pitch trim), I know I can fix this by disengaging the AP, however I want a smoother flight, is there anyway to fix this?, because I want a smoother flight with the AP and Alt AP on. Thanks in advance.

As you climb, start to decrease your VS and don't forget to change from KIAS to MACH around the time you are climbing through FLT260.

Ok I'll try to do that and see if it fixes the problem, thanks.

It's still unnecessarily pitching up 😞

20 minutes ago, Hampster said:

It's still unnecessarily pitching up 😞

FSX disc version or FSX Steam Edition?  Also, what is Alt AP?  What is your fuel load?

@Hampster, at which airspeed are you climbing? Also, do you have pitot deice on?

11 hours ago, charliearon said:

FSX disc version or FSX Steam Edition?  Also, what is Alt AP?  What is your fuel load?

I'm at FSX Steam Edition, uh Alt AP is the Alt Hold button, my fuel load is at max

10 hours ago, Luis Hernandez said:

@Hampster, at which airspeed are you climbing? Also, do you have pitot deice on?

I'm at 280 Knots climbing for FL380 at an altitude of around FL180, and I have the Pitot Heat Switch on.

OK, normally a 737 will not take off with a maximum fuel load.  This is probably the cause of your wild pitching up.  Your aircraft is so heavy the engines are struggling to gain altitude.  The next question is how many miles is your flight?  Next question is are you using ATC to give you directions or are you just flying on your own?

I normally did 1 hour to maybe 2 hour flights like KSFO to KSAN.  Usually my cruise altitude was 36-38 thousand feet and my fuel load was no more than 40% in each of the 3 tanks.  Carrying full tanks will require you to do long, slow step climbs to burn off that much fuel.

Get familiar with this screen before starting your flights!

 

Just fly the climb at the speed you would like adjusting the AP rate of climb to keep that speed. Do not use IAS speed hold, although if the AP has N1 hold, use that,. 
If the vertical speed becomes too low then use a lower reference speed.
That takes care of almost any fuel or payload.(OFC within realistic limits)
Hand flying the AP VS like this is the same as if the AP had a FLCH mode.

If the sim aircraft has a FMC, the FMC computes the required speed itself but basically flies the aircraft the same as above if on the FMS / VNAV mode.

A "general" climb schedule that works for almost any airliner :
< 10,000 feet, adjust vertical speed to maintain 200 (terminal area) to 250 knots
> 10,000 feet to transition altitude (18,000 feet in the US),  adjust vertical speed to maintain 300 knots
> 24,000 feet adjust vertical speed to maintain MACH 0.70
At cruise altitude adjust throttle for for cruise speed / fuel rate or engine EPR  


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