747-400 strange behaviour


#1

I had 12h of fuel onboard the 747-400. I put flaps 10 for T/O and when I retract them fully my aircraft pitches up to 12 degs when I’m only climbing at about 1000fpm. It’s more than the 787 which you guys said it was normal to have such a pitch angle. Is it also normal for the 747-400 to behave this way? The A380 doesn’t have this pitch issue.


#2

Hey!

The A380 have the opposite “issue”, pitching down. But that’s because the physics are way off for anything but regional flights (this since pre-Global)

What weights besides for the 12hrs of fuel do you have entered on the 747 and at what speed do you retract flaps?


#3

I have this issue essentially everytime I fly the 747! I’m climbing at a speed of 220 and at say 1500ft/min with 150000kg of fuel, 400 pax and 5t of cargo. I retract flaps from 20 (T/O) to 10 and the plane pitches up sharply.


#4

If I remember correctly it was above 200kts when I started retracting flaps. If I kept flaps partially extended throughout the flight the pitch wouldn’t have been so high but would’ve caused a lot of drag.

I also think the A380 is a little weird but since it pitches down to 0 degs instead of up I won’t complain (doesn’t mean I cool with it).

So is this a bug or it’s just my poor flying skills?


#5

I would say it’s probably pitching up a bit more than it should, and i think it’s a general thing with more than this aircraft in Infinite Flight to be honest.

I know some of them can’t be much more accurate than they are, since we have real world pilots testing them before we release. But we don’t have that amazing opportunity available for all the aircraft, so the physics are only based on numbers. And sometimes having only the numbers, won’t do things justice :)


#6

Will a rework be considered for the 747-400?


#7

Most certainly! We have others that are in way worse shape though and will probably need some love before the 747, but we’ll get to the 747 one day.


#8

If the flaps are retracted with max gross weight, the plane will have to pitch way up to maintain the same VS.

We’d have to know which weight, altitude and speed you were going at to make sure. (also, temperature and field elevation at the time helps too)


Aircraft pitching too high?
#9

I can’t seem to upload a screen recording on my device here as it says only .jpg format is allowed.

Total weight: 319,282kg
Speed: Around 220-230kts flaps fully retracted, at 250kts below 10,000ft weird pitch angle is still there
Altitude: Around 5000ft

These aren’t exact numbers because the speed and altitude keep increasing, to be on the safe side I’ll say the flaps start retracting above 200kts and I was definitely above 4000ft when all of these happened. I was only at 6000-7000ft when I had to fly at 250kts because the pitch angle made it seem like my plane was “too heavy”.


#10

Did I provide the correct information? May I get an update about this issue? @schyllberg @Laura


#11

you need to be careful while retrecting the fllaps and try to reduce the VS while you retract to avoid the nose to pitch up


#12

I already reduced the VS to less than 1000fpm and yet the aircraft still pitches up abnormally high.


#13

Yes, this has happened to me before. It kinda happens on the -200 too!


#14

I would say maybe it’s bc the aircraft haven’t been reworked that’s why it behaves unrealistic, it’s same like a330 when u set flaps full.
I believe this will be fixed it when it comes to rework.


#16

You totally should otherwise you won’t understand the purpose of this support thread involving the 747.


#17

Sorry bud-used the wrong account. I’ve had issues w the 744 myself-I’ve held the flaps to 1* past 230kt on occasion to ensure easier pitch angles. I’ll put some screens in for you.

Here’s a climbout from a cold (good flying air) KBOS at ~85% load. I still need ~10* pitch to grab 1500FPM climb at 250kt with the flaps up. Boeing A/C do this from my research. In IF it’s all about where the FPV is-hope this helps.


#18

It shouldn’t be that high even your weight is >MLW, your speed is at 250kts below 10,000ft so you can’t go any faster to reduce the pitch angle. It’s funny to keep flaps 10 throughout your flight right?


#19

I’m climbing out at 250kt /1500VS and flaps up over MLW and that results in a decent up angle.


#20

So that’s a problem the developers have to rework but I think that won’t happen anytime soon.


#21

Although the previous posts are completely viable, just keep in mind that in real world aviation heavy aircraft can request a higher speed than the governed 250kt limit below 10kft.

Do you get this issue at higher flight levels? Probably not because you are travelling quicker. The heavier your weight, the higher the speed you need to be at before cleaning up your aircraft by retracting flaps.