PAX on board ?

[Xavier]

Hi Hardy,

I didn't have the opportunity to say it yet, so here is : thanks very much for this very unique sim, you just succeeded in making it exactly as it was dreamt by so many of us...

Little question though : how does PSX assume the number of passengers (or supernumaries for that matter) on board ? I would initially have thought that this was of no use for the sim as the ZFW/CG would be the only relevant impacted values, until I considered the O² rate of consumption problem...

arised after a main cargo deck fire, hence decompression, and I decided to keep a pretty high FL for perf reasons assuming I had plenty of 0² onboard for the 2+6 POB, but realized that the passenger bottle was decreasing quickly ; don't know if any company would allow this type of strategy though... mine would but completely different activity

Thanks for the great work,

Regards

Xavier

[Hardy Heinlin]

Hi Xavier,

PSX's pax aircraft are always full of mamas, papas, and crying kids; and the freighters always carry some supernumaries for the horses.

The consumption depends on the aircraft altitude. At FL400 it's about 7 times higher than at FL140, for example. One reason why you should descend as fast as possible.


Regards,

|-|ardy

[Xavier]

Hardy,

That's copied. So max POB at all time when O² comes into consideration.

In my company we can, according to the Alt Vs O² rate chart and considered flight time, maintain a certain level above FL100 with O² after decompression, if that solution provides a better overhaul efficiency and safety (high ground level, weather, fuel req. ...).
However we work under Part 91 / EASA SPO, that is aerial work, so what is acceptable for us might not be authorized by any 744 operator...

 Thanks for the fast reply !

Cheers

Xavier

[John H Watson]

I decided to keep a pretty high FL for perf reasons assuming I had plenty of 0² onboard for the 2+6 POB, but realized that the passenger bottle was decreasing quickly ; don't know if any company would allow this type of strategy though... mine would but completely different activity

As far as I know, cargo airlines like Atlas only have one bottle for supernumary personnel (size unknown). The flight crew usually have two bottles. This raises interesting questions regarding fire suppression. Most 744F's don't have any extinguishing systems on the main deck (apart from portable extinguishers). The fire suppression system uses reduced cabin pressure to inhibit the spread of fire. However the pressure is held at 25,000', I recall, so oxygen use should be lessened if the airplane flies at that altitude (also).

Rgds
JHW

[Xavier]

John,

Thanks for the insight.
That was actually part of my decision process : long way to diversion and unknown status of the fire (apart from loops of course) with only the high cab. alt. as a fire suppression mean : staying high under O² so that I maintain conditions in the cargo deck where fire is not likely to sustain made sense to me

(I sadly could not find any 744 cargo ops SOP on the internet, which would have helped with that decision)


Regards