A380 Physics Issues

Device<iPad 7th Gen>:
Operating system<iPadOS 18.3.2>:

The A380’s flight characteristics and aerodynamic physics are, for lack of a better term, screwed up. It should not take 90% THS trim to maintain a 7.5° attitude at 250KIAS. It just doesn’t make sense.

You can see airplane weight, GS, attitude, altitude, THS position, etc in the attached screenshot. I’ve experimented with ballast via cargo holds but it doesn’t do much or make much difference, but I’m open to all suggestions.

Thanks!

I have noticed that. If I am right, you will cruise between 70% to 64% trim, then back to about 80% on approach, and these are all higher than they should.

It could have to do with weight. You’re 80% load I see.

Well, it would still be about 70% trim at 45% load…

1 Like

The trim system is so weird and I agree it’s higher than what’s actually irl.

1 Like

I mean, I’ve only used the A380 once, and I used 20% trim takeoff and landing with no issues.

2 Likes

I know, but when one wants to get rid of the magenta thing, one has to trim up a lot!

2 Likes

Don’t get it, but okay :rofl:

I use +2% trim for takeoff and landing

1 Like

and what’s your rotation v/s?

I wouldn’t read too much into any rotation neutral trim number.

Trim is nuanced and challenging to implement within the control limitations of a sim.

I’d argue the dynamically changing forces against which you could use trim to offset, are generally roughly originating from the right cause and have roughly the expected correct feel, to the extent possible for the context of IF (or any portable device or pc based sim).

Load balance and other related complexities could be further implemented, but likely with diminishing returns of usefulness.

Without more than 30% trim it won’t be possible to takeoff at heavy loads unless you go full power which is overpowered.

Sometimes 2,800fpm to 2,100fpm and 1,800fpm at 88% N1

and VR speed?

180kts to 157kts to 171kts IAS

My long haul configurations are Typical vR speeds less than 165kts and v/s are usually under 2000v’s for upto 1000ft and thrust settings I usually use 80-82% (flex settings) and flaps 1 or 2 and trim around 36-45% depending on the SID.

Trim has nothing to do with the aerodynamics of getting off the ground. It only assists with the rotation.

For example you can try what I just tested:

Trim 100% down (rather than up or neutral), and take off above even MTOW, and with 85% power.

Long runway roll to achieve sufficient speed but the lift off is achieved with the same pitch up angle as for any other trim setting.

2 Likes

I will try that and will let you know the result I’ve been on bluestacks for so long which required me to use lot of trim for roll since I can’t dynamically roll like I can do currently when playing in my phone.

Hi !

Sure, nothing aerdodynamic there, but still : if you fly level at a given altitude, with a given plane and at a given speed with all set on autopilot and the phone flat on a desk, you’ll have to trim to a value to make the coloured out of trim thingy vanish.

For instance, an A380 with 405k kg level at 28000ft and 320kt IAS would need about 23 % trimming.

And as far as I know, this value would be the same for any user.

Now, given a user sensitivity settings, the effect of being out of trim could be minimal or strong. At least, this is how I understand the trimming in IF. I might be plane wrong (pun intended!) :wink:

Your load is 80%

:thinking: