# Air Traffic Control lingo question **URL:** \ **Category:** Factual Questions\ **Created:** [July 5, 2004, 2:09pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640 "2004-07-05T14:09:12Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![legion](https://avatars.discourse-cdn.com/v4/letter/l/838e76/32.png) [@legion](https://boards.straightdope.com/u/legion)\ **Post date:** [July 5, 2004, 2:09pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/1 "2004-07-05T14:09:12Z")
What does the “heavy” mean in, for example - “American five eight seven heavy Kennedy tower caution wake turbulence runway three one left taxi into position and hold.” ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [July 5, 2004, 2:12pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/2 "2004-07-05T14:12:04Z")
I believe it refers to a commercial passenger jet, as opposed to a smaller plane. Think Boeing 737 and larger. They’re called “heavies” because they’re, well, heavy. ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [July 5, 2004, 2:39pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/3 "2004-07-05T14:39:34Z")
A little checking reveals that a “heavy” is an aircraft weighing 300,000 pounds or more. From [this site:](http://virtualskies.arc.nasa.gov/ATM/tutorial/tutorial4.html) > [@](#): > > A further complication is all aircraft produce wingtip vortices. Vortices are caused by generating lift from the wings. The vortices generated by a small aircraft are not nearly as troublesome as the vortices generated by a “heavy.”“Heavy aircraft” (aircraft weighing 300,000 pounds or more) and Boeing 757 aircraft, generate vortices with a strength of small tornadoes. Wingtip vortices generated by a large jetliner can cause tremendous turbulence for a much smaller aircraft if it is following too close behind. There has to be a greater separation in distance and time when a “heavy” is in the traffic mix. Wingtip vortices can cause problems no matter the size of any of the aircraft if safe separation is not maintained. ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [July 5, 2004, 2:49pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/4 "2004-07-05T14:49:16Z")
From Boeing’s tech specs (at [www.boeing.com](http://www.boeing.com)): Over 300,000 lbs gross takeoff weight: 747, 767, 777 Under 300,000 lbs: 717, 737, 757 (though from the quote in my other post, it appears that the 757 is treated like a “heavy” because of the vortices it generates - its gross takeoff weight is 272,500 lbs). The Airbus website may contain similar info, but if it does, it’s buried in there somewhere, and I can’t find it. ---
**Author:** ![pilot141](https://avatars.discourse-cdn.com/v4/letter/p/e0b2c6/32.png) [@pilot141](https://boards.straightdope.com/u/pilot141)\ **Post date:** [July 5, 2004, 4:55pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/5 "2004-07-05T16:55:55Z")
Just going from memory, I believe the A300/310, A330 and A340 are all classified as “heavy” on the Airbus side. Military aircraft can also have “heavy” appended to their call sign: the C-141, C-17, KC-10 and C-5 are all capable of flying at greater than 300,000 lbs. ---
**Author:** ![JimMacMillan](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@JimMacMillan](https://boards.straightdope.com/u/JimMacMillan)\ **Post date:** [July 5, 2004, 5:37pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/6 "2004-07-05T17:37:51Z")
> [@legion](#): > > What does the “heavy” mean in, for example - > > “American five eight seven heavy Kennedy tower caution wake turbulence runway three one left taxi into position and hold.” Legion, The following is an excerpt from AOPA’s (Aircraft Owners & Pilots Association) website. Jim * * * If you ever share an airport with large aircraft, including airliners and cargo aircraft, you’re sure to hear controllers warning pilots about heavy aircraft. The word is typically used in conjunction with a wake turbulence advisory. When a controller warns you, for instance, that you will be landing behind a heavy aircraft, he or she is referring to an aircraft that is capable of takeoff weights that are greater than 255,000 pounds, regardless of the aircraft’s current actual weight. Some lighter aircraft that are known to create severe wake turbulence, such as the Boeing 757, may also be designated heavy. ---
**Author:** ![legion](https://avatars.discourse-cdn.com/v4/letter/l/838e76/32.png) [@legion](https://boards.straightdope.com/u/legion)\ **Post date:** [July 6, 2004, 12:07am UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/7 "2004-07-06T00:07:10Z")
Thanks all. ---
**Author:** ![Lord\_Mondegreen](https://avatars.discourse-cdn.com/v4/letter/l/91b2a8/32.png) [@Lord\_Mondegreen](https://boards.straightdope.com/u/Lord_Mondegreen)\ **Post date:** [July 6, 2004, 6:43am UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/8 "2004-07-06T06:43:47Z")
The use of “heavy” is not universal. ATC in Australia for example do not use the term. I have no idea how widespread its use is. Any Europeans, Africans, Asians, South Americans, etc. able to comment? ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [July 6, 2004, 10:06am UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/9 "2004-07-06T10:06:43Z")
I wonder if the use or non-use of the term is connected to how ATC manages traffic. Do Australian regulations set aside some airports as strictly for the big airliners and air cargo, so one can resaonably assume all planes going into and out of such an airport are heavies? Here in the US you can get a huge range of traffic using the same facility. I myself have flown a two-seat Cessna into an airport at the same time as passenger airliners (they put me in front of the big guy, in fact) so the use of “heavy” reminds not only ATC of the big guys, it’s a useful reminder to little squirts like me to be cautious around them. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [July 6, 2004, 11:57am UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/10 "2004-07-06T11:57:44Z")
> [@Broomstick](#): > > I wonder if the use or non-use of the term is connected to how ATC manages traffic. Do Australian regulations set aside some airports as strictly for the big airliners and air cargo, so one can resaonably assume all planes going into and out of such an airport are heavies? All airports in Aus are available for all aircraft (though you may have difficulty getting a clearance into Sydney in a C152, and the more major airports have satelite fields that cope with light aircraft). New Zealand is another country that doesn’t mention “heavy” but in both countries you often get American pilots anouncing that they are a “heavy”. It’s a little redundant as we generally know that a United Airlines flight from LA is not going to be a B737 :). ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [July 6, 2004, 12:01pm UTC](https://boards.straightdope.com/t/air-traffic-control-lingo-question/253640/11 "2004-07-06T12:01:16Z")
Heck, this is a country that has B737s flying into non-radar, non-controlled MBZs with motor-on-a-handglider style microlights as conflicting traffic!