New PSX video on YouTube

[Hardy Heinlin]

Just in case someone wonders why N1 on the two failed engines was exactly 0.0 and not windmilling:

This was an F.O.D.

The N1 shafts and accessory shafts were stuck due to foreign objects. EDPs have stopped as well. When that happens on all 4 engines, you have no EDP and no bleed air anymore, and therefore no demand pump anymore. Your controls will be completely dead.

I don't know what kind of foreign objects they were ... Blood is not modelled in PSX. May have been birds or skydivers ...


-|ardy

[Kurt]

May have been birds or skydivers ...

Close encounters between skydivers and airplanes do actually happen due to the vicinity of runway and landing area for skydivers. Recently there has been a collision - luckily only with minor bruises for the pilot and skydiver:

https://www.youtube.com/watch?v=LVdDOonvhcU

BTW Hardy, - are you using a physical MCP like Aerosoft MCP 747 in the demo? - Can´t see you touching the MCP with the mouse all times you change a knob..

Cheers

Kurt

[falconeye]

falconeye,

Why do you expect to hear the Flaps Power Packages (FPP)?
The FPPs are in the main body landing gear wheel well. You may hear them in the cabin but they are very far from the cockpit.
It is a big aircraft after all  

Cheers,

Well, I was not aware, that the difference from what you hear in the cabin and what you hear in the cockpit so huge. Sometimes as a passenger you can hear the extension of the flaps so loud, that I would expect it to hear in the cockpit as well. But it seems I was wrong.
I have never been in the cockpit of a 747 during flight, so no real experience.
Nevertheless the sound of PSX is really great
Cheers

[Hardy Heinlin]

Kurt, in the video, I'm sometimes using the mouse (e.g. blank the MCP SPD, push LNAV), and mostly have the virtual PNF push the buttons while I'm handflying. When the A/P is engaged, I have to push the buttons myself.


Cheers,

|-|ardy

[John Golin]

For comparison...

https://www.youtube.com/watch?v=q3SCr11eqNQ

[John H Watson]

Well, I was not aware, that the difference from what you hear in the cabin and what you hear in the cockpit so huge.

For obvious reasons, the windows are much thicker in the cockpit: namely for bird strike tolerance, and the greater size of the windows means they must resist a greater cabin pressurisation force. Also, at speed, wind noise is much greater at the front. Occupational Health and Safety have the pilots wearing noise cancelling headsets these days. Engine noise is predominant in the cabin (especially in "cattle class"  :mrgreen: )

[Tetsuo]

Hardy,

Thank you for your great job and I'm so excited for the release!
By the way, I have a question about this video.
Why are the direction and the speed of the wind so stable on the ND especially in spite of sever turbulence?
I remember they are more fluctuating in ps1.3

Thanks,
Tetsuo RJOO

[falconeye]

Perhaps Hardy has fixed the wind in the Instructor window. Makes the flying a little easier I think.

[JP59]

Absolutely wonderful, I listened with HiFi headphones, the sound is amazing  

[Hardy Heinlin]

Tetsuo,

whether or not the wind data are (relatively) stable on the ND depends on the kind of turbulence that is set on the Instructor.

In the video, there are no gusts and no wind direction changes set on the Instructor, if I recall correctly. There is just a "general" turbulence layer set which produces pretty chaotic air movements, including vertical movements.

When you set gusts or variable wind directions, the wind data on the ND will indicate this.

However, note that the ND data are computed using ADC and IRS sensor data. To determine drifts, data must be monitored over a certain period of time in order to recognize a trend. This requires time, and the indication is accordingly slow. It always lags behind the actual physical motion. It additionally includes a damping algorithm (like on the PFD speed tape, altitude tape etc.).

Like in real life, the IRS model in PSX has to calculate the data. The IRS model does not get the data directly from the aerodynamics model or weather model. No fake :-)

E.g. when the ADC provides wrong TAS data, the IRS computed wind data on the ND will refer to that wrong TAS and indicate wrong wind speeds and directions. This realism would not be possible if the model would cheat and get the data directly from the weather god.


Cheers,

|-|ardy


During takeoff roll and landing rollout, the wind arrow is always vertical. This is because the aircraft stays on the runway and doesn't drift sideways, i.e. the IRS senses that the track and heading are equal, hence, the IRS thinks the wind is coming either from 12 o'clock or 6 o'clock.

[falconeye]

During takeoff roll and landing rollout, the wind arrow is always vertical. This is because the aircraft stays on the runway and doesn't drift sideways, i.e. the IRS senses that the track and heading are equal, hence, the IRS thinks the wind is coming either from 12 o'clock or 6 o'clock.

Interesting reading. It seems to program the IRS alone is difficult enough. I am too lazy now to start PS1.3, but as far as I remember the arrow disappeared more or less directly after the landing and was only visible when airborne. So PS X is more realistic in this aspect too.
Cheers

[Tetsuo]

Hardy,
Thank you very much for your kindly reply.

Tetsuo

[Hardy Heinlin]

So PS X is more realistic in this aspect too.

There are countless differences between PSX and PS1. Some features in PS1 were just absent, or simplified, or wrong.

One important difference:

Under asymmetric thrust conditions, to keep the heading constant, PS1 wanted you to kick the rudder until the ball is centered.

In PSX, you should kick the rudder until the heading stops drifting. And when stabilized, the ball will not be centered; it will still partially remain off the center on the good side. The ball offset depends on the thrust vector difference (not big when an inboard engine fails and the thrust is low; very big when an outboard engine fails and the thrust is high).

In PSX, if you kick the rudder until the ball is centered, you will overcompensate the asymmetry and the heading will drift toward the opposite side.

I have checked this effect on a 744 simulator and also on a classic 737 simulator with mechanical balls. The effect is the same. Hard to understand, but it seems to be a general rule.


Cheers,

|-|ardy

[falconeye]

And I thought PS1.3 was close to perfection.(on the aerodynamical side of course, not on the graphical side)

[Hardy Heinlin]

"Close" is not 100% :-)

[Alec246]

Amazing to hear the details of the PSX FLight Model.

May I ask if the FM simulation is locked to the Sim Fps? I mean, if the sim is running at 20fps, will the FM be less accurate and smooth than if it were running at 80 for example? Or does it run separately from the Visuals, and it's always locked at a certain frequency?

[GodAtum]

I guess PSX is not affected by the FSX ground friction bug?

[Hardy Heinlin]

The velocities in all models refer to time, not to frame.

100 knots at 5 fps remain 100 knots at 72 fps.

The same is true for the clocks, weather, fuel pumps, speech etc.

The fps only tells you how many pictures you see per second. It does not affect the actual life behind the pictures.

[jalexb88]

The ATC seems much better than anything for MSFS, to what extent is it simulated? Does it give vectors and altitudes according to local terrain and traffic? Can ATC give a "cleared direct XX fix" or is it just "cleared on course", not that it matters that much but I was curious.

Alex

[Hardy Heinlin]

The ATC model does not watch terrain, only airport elevation.

The ATC model may give a "direct to ..." for holding patterns.


|-|ardy