I have heared at ATC communication that some aircraft uses a heavy word in the call sign.

What does heavy means?

When it is used?

Is it used when aircraft is heavier than 200-300 tons?


The rules are slightly different in different countries, but common for all is that the "heavy" designation is used for aircraft in the heavy wake turbulence category, that is, aircraft with a maximum takeoff mass of 136 tonnes or more (see Is there a definition of light/medium/heavy aircraft?).

Some countries require aircraft to use the heavy suffix to their callsign in all radio transmissions. Others only require it on initial contact with a new ATS sector, whereas others still will additionally require it to be used at all times in the aerodrome environment, but only on initial call in the en-route environment. The local rules will be listed in the AIP for the country in question.

Also note that in some places, certain aircraft types are considered to be in the heavy category, even though their MTOM is below 136 tonnes. The typical example of this is the Boeing 757, which is put in the heavy category by some countries because it creates significantly more wake turbulence that other aircraft with similar MTOM.

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    $\begingroup$ As to why those rules exist, I read somewhere that it's so ATC doesn't forget to apply the extra separation required since heavies (and supers) are relatively rare. $\endgroup$ – StephenS Jan 27 '19 at 16:34

The term heavy is used during radio transmissions between air traffic control and any aircraft which has been assigned a maximum takeoff weight (MTOW) rating of 136 tonnes (300,000 lb) or more.

More at Wikipedia (source of the cited text) and SKYbrary.

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    $\begingroup$ A special case is the 757, which is considered as "heavy" even though its MTOW is below the mentioned MTOW due to the wake-turbulence it produces $\endgroup$ – DeepSpace Jan 27 '19 at 9:35
  • $\begingroup$ Sorry, but this is incorrect. A 757 is not considered a heavy. It was treated differently for wake turbulence, and still is in a less severe way, but a 757 is not a heavy per the MTOW regulation. $\endgroup$ – customcables067 Apr 2 '19 at 5:42

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