1. when should i connect to ground air conditioning and ground air-start unit? curently i just connect to ground power to configure the basics (nav on, route, etc...) and when all passengers are onboard (fspassenger) i turn apu on and disconnect ground power.2. what this GSH means?

2) "GSH" is the name of the next waypoint you'll be passing

You don't really need the air start unit. As far as I know the air start unit is mostly used when the APU is u/s. It would be uneconomical for the airline company to use an air start unit instead of the APU.

2) "GSH" is the name of the next waypoint you'll be passing

but that symbol means anything?

Looks like a VOR symbol to me.

This symbol?

1) From what I've experienced: Air start means APU is inop.Ground A/C also means APU is inop and the OAT is high. The only times I have seen exceptions were during the first gulf war where airlines were doing things to reduce costs. (Including stripping of livery paint, more use of GPU (ground power units), Jets taxiing on one engine, limiting the use of the APU etc...) Side note: Air Start Carts are very loud and can be heard almost everywhere in the plane2) GSH is the VOR that the radios are tuned to. The symbol is that of a VOR. (VORs, NDBs, Intersections, all have different symbols on the map and the NGX is using the typical VOR symbol)

1) From what I've experienced: Air start means APU is inop.Ground A/C also means APU is inop and the OAT is high.

Many airports in the western world have rules about using the APU cause of the noise, it's common to start the APU a couple of minutes before engine start. Instead they use a GPU and an A/C unit (if it's hot outside) which is not as loud as the APU

Many airports in the western world have rules about using the APU cause of the noise, it's common to start the APU a couple of minutes before engine start. Instead they use a GPU and an A/C unit (if it's hot outside) which is not as loud as the APU

Western World? Western Europe? Not sure what you mean by Western World, but I am in the U.S. and my experience comes form major airlines in the NYC area. Hopefully others will share their experiences in this thread.I have not had that experience. (Not saying it isn't true, as I have seen it posted in AVSIM before) I apologize for not answering your actual question, but from my experience, it is as late as 10 minutes prior to deprature (when APU is turned on and used) and as early as the crew first boarding the aircraft. If your particular airport has APU noise restrictions, I'm sure there is a published time frame as well.

Western World? Western Europe? Not sure what you mean by Western World, but I am in the U.S. and my experience comes form major airlines in the NYC area. Hopefully others will share their experiences in this thread.I have not had that experience. (Not saying it isn't true, as I have seen it posted in AVSIM before) I apologize for not answering your actual question, but from my experience, it is as late as 10 minutes prior to deprature (when APU is turned on and used) and as early as the crew first boarding the aircraft. If your particular airport has APU noise restrictions, I'm sure there is a published time frame as well.

I can't see the crew using the APU for more than a few minutes if there is ground power/air available. So if a crew has to arrive at the aircraft one hour or more before departure, the APU is run that long?

Kenny: if GPU is unavailable, or very expensive, then yes, APU is run that long.

Western World? Western Europe? Not sure what you mean by Western World

The definition of western world isn't really geograpic, anyway heres a map, dark blue color is whats usally called the western worldhttp://commons.wikimedia.org/wiki/File:Clash_of_Civilizations.png