Hi fellow VATSIMers.
We all know that aircraft such as the 747, 767, 777, A340 and others are refered to as "heavys" because they have a maximum certificated take-off weight of 300,000 lb (136,000 kg) or more. So, while monitoring r/w ARTCC comms, I was curious why sometimes the crew of a 777 would include "heavy" with their callsign when checking in with the ARTCC and other times they wouldn't. So in the interest of keeping our hobby "as real as it gets", I did some digging on the FAA's website and found the following.
Go to http://www.faa.gov/ATpubs/ATC/Chp2/atc0204.html and scrol