Here's the skinny
The Heavy call sign is used by all A/C that are certificated north of 255,000 including 757's due to the wake turbulence issue with those aircraft, regardless of the current weight of the A/C, IE if your on a ferry flight and are light as a kite you still use the Heavy call sign.
It is only used for tower, approach and departure.
It is basically a backup reminder for the controller ( as its already designated on your strip) to give adequate separation. Center controllers give everyone the same separation so no need for the Heavy call sign.
It also helps the pilot behind you adjust accordingly to stay out of your wake zone, IE flying one dot high or slowing down.
Hope this helps.
The Heavy call sign is used by all A/C that are certificated north of 255,000 including 757's due to the wake turbulence issue with those aircraft, regardless of the current weight of the A/C, IE if your on a ferry flight and are light as a kite you still use the Heavy call sign.
It is only used for tower, approach and departure.
It is basically a backup reminder for the controller ( as its already designated on your strip) to give adequate separation. Center controllers give everyone the same separation so no need for the Heavy call sign.
It also helps the pilot behind you adjust accordingly to stay out of your wake zone, IE flying one dot high or slowing down.
Hope this helps.