Well i have a few questions that need answered please!

 

1. i'm doing a long flight 4 hours lets say i have a 2 step climbs, 350, 390 something like that i'm using fs2crew also. when entering my cruize alt into the FMC will enter the final cruize alt or the first alt?

 

2. i've been reading the fcom manual 1 and 2 about the pre conditioned air. you have to entry points one at the maifold AIR CON and the other one called the external air con is the external air con basically the external air start in the ngx FMC? and why is the need for two? 

 

I

 

 

1. i'm doing a long flight 4 hours lets say i have a 2 step climbs, 350, 390 something like that i'm using fs2crew also. when entering my cruize alt into the FMC will enter the final cruize alt or the first alt?

 

Initial cruise.

 

 

 

2. i've been reading the fcom manual 1 and 2 about the pre conditioned air. you have to entry points one at the maifold AIR CON and the other one called the external air con is the external air con basically the external air start in the ngx FMC? and why is the need for two? 

 

The external AC cart is low pressure air.  If you were to turn it on and point it at your face, it would feel like a cool (or warm, depending on the setting) fan in your face.  Much like sticking your face in front of a regular desk fan.

 

The air start cart is high pressure air.  If you were to turn it on and point it at your face, it would hurt...a lot...partially because it's blowing air with such pressure, and partially because that would likely rip the hose out of your hands and make it flail around.  If it hit you, you'd be going to the hospital, because the collar and handle are metal.  In other words, that thing puts so much air through the nozzle that the collar is too hot to touch after an air start.  That's how much air is getting pushed through there.

 

External AC is used to keep the plane cool.

Air start cart is used to start the engines (and it could be used to run the packs, too, but most operators avoid that, as running the packs just wears them out faster).

so i'll enter 350 and when i come to my step climb 390 into the fmc and mcp plus press mode control ? will this affect fs2crew in anyway do you know?

 

 

just been reading the fcom SP 2.1 EXTERNAL AIR CART USE AND GROUND AIR CON CART USE.

 

one has packs on and the second has packs off?

 

 

so i'll enter 350 and when i come to my step climb 390 into the fmc and mcp plus press mode control ?

 

Enter FL350.  Cruise at FL350.  When ready to step to FL390, roll the MCP altitude window to FL390 and press ALT INT.  That should automatically update the CRZ ALT on the CRZ PAGE of the CDU, if I remember correctly.

 

 

 

will this affect fs2crew in anyway do you know?

 

FS2Crew sets your CRZ ALT on the overhead pressurization panel based on the altitude you set as your initial cruise as you set the flight up.  Because of this, you'll need to update it to the new higher altitude when you step, I believe.

 

 

 

just been reading the fcom SP 2.1 EXTERNAL AIR CART USE AND GROUND AIR CON CART USE.
 
one has packs on and the second has packs off?

 

Yes and no...

 

Yes, with high pressure air (air start cart), you can use the packs, but as I noted before, airlines generally don't.  They only really use the air start cart right when they're ready to start the engines, where you're going to have the packs off anyway.  Up to that point, they generally use low pressure air, which does not pass by the packs at all.

 

So, generally, you:

• Land
• Turn the APU on
• Taxi in
• Transfer elec to the APU
• Shut down your engines
• Turn packs off
• [Ground connects EXT PWR and LOW PRESSURE AIR]
• Transfer elec to GND
• Turn APU off

When you're ready to go again:

• Turn APU on
• Transfer elec to APU and leave packs off (use external low pressure air as long as you can)
• If you anticipate a long delay between the ground personnel disconnecting the low pressure air and engine start, turn the packs on; otherwise, leave them off
• Start engines
• Turn packs on

The only time you really use high pressure air (air start cart) is when your APU is INOP and you need another source of high pressure air to start the engines.

 

 

TL;DR:

You will probably never use high pressure air (air start cart) unless you're simulating non-normal procedures.  See this video for an example:

There are 2 points to which you could connect external air. The Supplemental Procedure that you'd use depends on.. 1) what external air you give to the plane, and, 2) how you intend on using it.

 

You pointed out that one procedure says packs off, and one says packs on auto or high. This is because the 2 connection points give air to the plane at different points of the airplane's air system. Without getting too complex:

- using the air start cart gives air to the entire air system (thus, it's permissible to run the packs)

- using the pre-conditioned air cart (air conditioning cart) gives air to part of the system... <This external air bypasses the packs altogether> (thus, you don't run the packs).

 

If you use the Air Start Cart, use SP.2.1 External Air Cart Use.

If you use the Pre-Conditioned Air Cart, use SP.2.2 Ground Conditioned Air Use.

 

Although both carts can be connected to the plane at the same time, both carts aren't typically used simultaneously - meaning - you use one or the other, not both at the same time.

 

Brian Nellis.

Hi.

 

For step climbs, the manuals say to manually change the altitude in the FMC, then the alt MCP window, and the overhead pressurization panel altitude, then alt intervention. I don't know how this affects fs2crew.

 

Also, when using the air con cart, you don't use packs for 2 reasons:

1. The air inlet is downstream from the packs, so they wouldn't have any compressed air to run with;

2. Even if you were to get compressed air to run the packs from the APU or something else, the packs would overpower the ground cart and force air back up the hose, possibly damaging the cart.

thankyou guys for the response all makes sense