747-400 strange behaviour


#22

No I’m trying to say it’s fine. Because as your speed increases, your angle should go down-as @Mags885 asks-does it happen once you speed up? Heavier weights at 250kt will result in a higher nose angle to maintain a given vertical speed.


#23

Nope, I cruised at M 0.84, pitch angle was definitely above 5 degrees. Because of the <250kts below 10k ft rule that’s not possible. @Mags885 The problem happens when I retract flaps 10 to 5, I reduced my VS to less than 1000fpm but still the pitch angle didn’t reduce.


#24

Here is some data I posted in another topic, which was from my last real life flight before my vacation… one thing to add: Dont forget to trim your aircraft nose up, in a fully loaded 747 you should use around 30% nose up in IF. That will help you to reduce the loss of v/s when selecting flaps 5. I made a video for you in IF taking off in Denver with max take off weight,the take off and climb is all manual flown without Autopilot…

And here the data from the real flight MCO-FRA:

Take off weight: 339000 Kgs / 747367 Pound
Fuel on board : 102000 Kgs / 224871 Pound
T/O flaps : 20
T/O N1 : 95 %
V1 : 145 kts
VR : 161 kts
Flaps 10 : 186 kts
Flaps 5 : 212 kts
Flaps 1 : 231 kts
Flaps UP : 251 kts
Climb Rate : 1700 ft/min
Pitch : 12 Degrees

Then we got High Speed approved,
so we lowered the pitch to :

Climb Pitch : 10 Degrees
Climb Rate : 1500 ft/min
Accelerating to 330 kts IAS
climb power N1 : around 91%
Initial Cruise ALT : FL270


#25

@Cavan - it seems like it’s behaving correctly according to the real world pilot above :)


#26

Mine’s also like this, I still feel something’s wrong with the 747 physics because the pitch angle is abnormally high (distance between the nose and the flight path is too wide) at flaps 0 when at 250 kts. Also, flaps should be fully retracted below 10k ft. Even at 290 kts the pitch angle didn’t seem to reduce when it should because of the increased speed. 290 kts and 250 kts is a big difference in airspeed. I’m also not too sure but the N1 is also on the high range.


#27

I asked @Lufthansa061 separately in a PM if there was anything off with the physics of the aircraft specifically in terms of pitch angle. And it was pretty spot on apparently. Only thing we didn’t quite right is the dramatic loss of lift going from flaps 10 to flaps 5.

I’m the last guy to argue with someone who actually flies the thing :)


#28

I don’t know if such a pitch angle is normal but comparing to other aircraft’s, it doesn’t seem so to me.


#30

So, if someone who flies the aircraft… tells you it’s normal, you still feel it’s wrong? This is one of those moments i’d say that facts trumps feelings.

Aircraft behaves differently depending on models, that’s why you’re not certified to fly every aircraft model that exists just because you have a license :) Different models requires different training.


#31

You mean you fly the 747 in real life?


#32

No, but @Lufthansa061 does…


#33

When IF comes to researching and developing aircraft they get real world experts on how something flies, I would trust them when they say their sources are accurate and say the aircraft is accurate


#34

It’s weird to see that the 747 is cruising but from the side view it looks like the aircraft is still climbing.


#35

If you feel it’s weird, that’s fine. But there’s no issue with the physics on our model here, it’s just how the aircraft model is in real life as well.


#36

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