"Heavy" US callsigns

[Readback Correct]

Why the "heavy" in a callsign, such as "US123 Heavy"?

As I'm expecting it to be due to a "heavy" a/c ie 747 etc, the next question is do you get "mediums" and "lights"

[Pegasus77]

It is to make the radar controller aware of the fact that there is a heavy aicraft flying (i.e. with a max takeoff weight over 136.000 kg) and he needs to apply increased radar seperation, although he usually knows so already from the flightplan. This increased seperation does not apply behind a medium or light aircraft.

[HEATHROW DIRECTOR]

ATC doesn't necessarily know because airlines do change a/c type without telling us which is why we have them advise a/c type on first contact with approach control. In the UK we have 5 VORTEX categories - Heavy, Upper Medium, Medium, Small and Light. Pegasus is only partially correct as VORTEX separation on final approach applies through the weight ranges.. Eg Upper Medium has increased spacing behind Heavy; Medium, Small and Light have increased spacing behind Upper Medium, etc. Anything can follow a Light a/c at minimum spacing but Light a/c behind Heavy is measured in light years...

[Avman]

In answer to your question as I interpret it, only the "heavies" call as such. No, the "lights" and "mediums" do not identify themselves as such on the r/t.

[Pegasus77]

I stand humbly corrected by the Heatrow Director... <img src="smile.gif" border="0">

Didn't know about the Upper Medium category in the UK... Does that one apply to the 757 or is it a weight category of it's own??

[AAL_Silverbird]

Here in the "States" we use:

AIRCRAFT CLASSES- For the purposes of Wake Turbulence Separation Minima, ATC classifies aircraft as Heavy, Large, and Small as follows:

a. Heavy- Aircraft capable of takeoff weights of more than 255,000 pounds whether or not they are operating at this weight during a particular phase of flight.

b. Large- Aircraft of more than 41,000 pounds, maximum certificated takeoff weight, up to 255,000 pounds.

c. Small- Aircraft of 41,000 pounds or less maximum certificated takeoff weight.

[HEATHROW DIRECTOR]

Pegasus... No, there are other a/c in the Upper Medium category B707, DC-8, VC-10, IL-62.

[JJflyer]

Calling "heavy" increases situational awareness between aircraft. It is nice to know who you are flying behind. Knowing it is heavy you can take appropriate action.

Cheers