Aerowinx gravity/intertial effects

[B767300]

We previously discussed the impact of flying inverted on the fuel and IRS system. The IRS seemed to produce a ROLL and ATT flag while the fuel system lost the ability to pump fuel, resulting in the respective fuel pump messages and FUEL PRESS ENG caution.

Today I tried the 1&4 main tank gravity transfer while inverted and it seems that PSX doesnt really simulate gravity effects when it comes to fuel😅 I succesfully transfered tons of fuel while inverted.

Maybe a simple g-calculation could fix this. We don't need complex CFD fuel simulations😅 but say ≤0g's results in dry pumps and ≥0.1g's allows for gravity xfer, pump ops etc.

I'm not sure about the IRS problems, the 744 sim may use an older IDS and the vid you linked Hardy was of a 737 classic so maybe newer 744's, 748's, 777's etc. don't have this problem.

[ASCTU744]

The F-16 Block 50 -34 manual states that it also uses a ring-laser-gyro RLG. The block 50 is about as modern as the 747, but if it can compute inverted flight, so should the 747's RLG right. How different can they be, especially considering the updates most 747's received.

[ASCTU744]

After rewatching that 744 loop vid I found that even the standby ADI failed, no flags, but it got stuck at zenith. I believe that the software simply doesnt simulate these unusual attitudes hence why it produces these messages. Even a C152 ADI can handle a looping. And the PFD/ND flip much smoother in the level D compared to PSX, but that's a cosmetic thing😅. I also noticed that the stby ADI in PSX doesnt really reach anything above -60 deg, lagging behind the PFD.

[Hardy Heinlin]

Gentlemen, I have no interest in speculating about looping effects. It's irrelevant; no 747 operator does loopings :-)

The standby attitude is mechanically limited to +85 and -63 degrees or something like that. PSX models that limit; you can check it. The limit has been tested with a real standby attitude outside the panel, on the ground.

[ASCTU744]

Gentlemen, I have no interest in speculating about looping effects. It's irrelevant; no 747 operator does loopings :-)

The standby attitude is mechanically limited to +85 and -63 degrees or something like that. PSX models that limit; you can check it. The limit has been tested with a real standby attitude outside the panel, on the ground.

  Alright fair enough. I think that the fact that the stby ADI froze in that 747 loop vid (while obv not being connected to any IRU) shows that the level D itself wasnt designed to do loops either.

Hardy, atleast the cosmetics of the ADI flip around when it passes nadir/zenith😅 pretty please. (https://www.youtube.com/watch?v=6EgeXCvhKTM&t=51s)

It'd be nice, but it's not a prio at all. Just one last question hardy, but does the map/PSX world flip around when the nadir flip happens on the PFD?

[Hardy Heinlin]

I don't understand what you are criticising. In PSX, when the pitch passes 90°, the heading changes by 180° as expected, for logical reasons: The nose is now facing the opposite direction! You can't maintain a constant heading in a 360° loop. In a 360° loop the heading will change two times, namely when passing pitch +90 and pitch -90.

[ASCTU744]

I understand why my heading flips, but the map isnt supposed to flip right? With map im not refering to the ND btw, but to the outside world. So say you're passing -90, instead of seeing the runways and taxi lights below you flip 180 deg, they should remain stationary. I also noticed that world greys out near -90.

My other point was the PFD ADI/ND flipping to abruptly at nadir/zenith, while the level D seems to be doing that way smoother as seen at 0.51s in the above linked vid.

[Hardy Heinlin]

The outside world in PSX rotates by 360° within a fraction of a second when passing -90° pitch. This is known to users that regularly play with loopings in PSX directly over an airport. I've never cared about this effect as the outside world in PSX isn't designed to show details anyway. It's a simple solution to allow my outside view algorithm to pass the longitudinal singularity in a looping. Microsoft FS5 or FSX, for example, had a similar problem with a singularity; there it was the singularity at the poles on the globe: So FS simply stopped the aircraft when it was some miles before a pole. (In PSX, pole overflight was always possible.)

Re level D video:
Look, we don't know if the effect is EFIS software version dependent, we don't even know what EFIS software version that sim is using, and we don't know if that sim is using a real EFIS box at all or an EFIS simulation. 744 engineers that assisted in the PSX development sometimes noticed effects in level D and C sims that would appear on the real deck in a different way, different timing, or not at all. That's why I'm always careful. PSX is intended to simulate the real 744, not the level C or D behaviour. Secondly, I really don't care about cosmetics in a looping. It's the most irrelevant task, and I won't spend any week of my life time in that :-)

[ASCTU744]

That's totally fair:)