I believe the Squawk code is what ATC uses to identify your aircraft so they can track it.

A squawk code is a 4 digit code assigned to aircraft either by ATC or used by individual aircraft to indicate certain info. 

Flying IFR the squawk code is used to identify individual flights that are operating on an IFR flight plan.  The code can be any 4 digit combination, with a few exceptions, using the numbers 0 - 7.  You enter this code in the aircraft's transponder.  The transponder then electronically registers this code with the radar systems used by ATC.  In the IFR world this squawk code is automatically generated by the air trafffic control system and is generated on the flight strip that each controller gets as you fly through the system.  It's a secondary system used to identify aircraft other than their callsigns.

In the VFR world the standard squawk code is 1 2 0 0.  When a controller sees a blip on his radar screen, depending on whether the a/c is equipped with a transponder or not,  he may see several bits of info tagged to the little blip.  Usually an aircraft with a transponder will tell the radar system it's altitude, and squawk code.  If you are just tooling around under visual flight rules(VFR) you should be squawking 1200.  This lets any ATC person know right away that you are operating your aircraft under VFR rules and not under the control of any ATC folks.

Now when you fly into a controlled airport, one with radar services, while operating under VFR rules, the local controller will assign you a squawk code to enter into your transponder when you establish intitial radio contact with that agency.  This is again another way of identifying you in that persons ATC system.

There are 4096 possible codes that can be squawked.  Hence you may see a transponder refered to as a 4096 transponder.  Several of these are discrete codes and are only to be used in certain circumstances.

For example:  As we already said 1200 designates an aircraft operating under VFR rules.

7700 designates an aircraft that has an emergency condition.

7600 designates an aircraft that has lost radio communications.

7777 designates military aircraft on intercept missions.

Hope this isn't too much overkill.

Mike G.

Right ok thanks

Is it possible to put in 7700 into the transformer and get a reply?

I do not think that FS recognizes emergancy sitations.
To my knowledge there is no way to convey an emergency situation to ATC. If flying IFR about all you can do is cancel ifr than check for airports in the area and make a landing but even if you have a engine fire do not expect the fire trucks to great you on the runway.
Maybe in the future if we are lucky. 8)

Quote:



I'd even settle for declaring an emergency and getting immediate landing clearance. That wouldn't be too hard to impliment. Just set your transponder to 7700, select "Inflight Emergency" on the ATC Menu and ATC will then tell all other traffic to "Go Around" until you are clear of the runway.

I quite agree That is one I guess M$ overlooked for fs9.
The other thing I have noticed is ATC does not warn you if go above 250 KTS below 10,000 feet FS2002 would do this I wonder why they did not incorparate it in FS2004 ???
But I guess they have to save something for the future.

Lazy typing... I stand corrected.