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Flight number followed by "heavy"


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This came up from WIkipedia when I googled "ATC aircraft heavy designation":

 

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. ... Such "heavy" aircraft over 136 t create wake turbulence from the wings.

 

As f16 says, it's to minimize problems from the tremendous wake turbulence (that is, very strong small tornadoes off the trailing edge of the wingtip, also known as wingtip vortices). Note that the 757 used to be a "heavy," for call sign purposes, even though its max weight is around 255,000 lbs, since it generated extremely dangerous vortices, more so than many others near its weight. I don't know the current status of that, since some are saying it's no longer required for them to say "heavy."

 

I've seen things that say something like 'Such "heavy" aircraft over 136 t create wake turbulence from the wings.' (from Wikipedia), but the truth is that all aircraft (yes, even gliders) generate wake turbulence, just not with the strength that larger aircraft do.

 

As examples, most private pilots and above are familiar with "hitting your propwash" in a level turn, which is actually hitting your wake turbulence, but it's just a light bump. In my younger days (1970 or so), I lived about 60 miles south of Chicago -- this was before the days of TCAs and, later, Class "B" airspace, and before wake turbulence was known as well as it is now (they were just starting to appreciate how much of a menace it was) -- and flew from the Joliet (JOT) airport. One day I was heading north (but still west of O'Hare) in a Musketeer at around 2500-3000 MSL when I saw a jet airliner go left to right a few miles in front of me, and what looked like a couple of thousand feet higher. As I got roughly under its path I felt a couple of sharp jolts a couple of seconds apart. I then realized I'd hit its wake turbulence, but fortunately perpindicular, not parallel, so I didn't have the problem of a rapid roll to go with that. And, as those vortices tend to do, they had descended to my altitude.

 

Note that the slower an aircraft goes (in other words, higher angle of attack), the worse the turbulence they generate.

 

A final anecdote: One day I was in a park just under the approach path to a runway at the old Stapleton airport in Denver. I watched a couple of airliners come over and land. Shortly after each came over, there was a loud rushing sound, and the trees on either side of the approach path (it had been cleared) waved wildly in the vortices from each of those jets.

 

Hope this helps clarify things.

 

Larry N.

As Skylab would say:

Remember: Aviation is NOT an exact Science!

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This came up from WIkipedia when I googled "ATC aircraft heavy designation":

 

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. ... Such "heavy" aircraft over 136 t create wake turbulence from the wings.

 

As f16 says, it's to minimize problems from the tremendous wake turbulence (that is, very strong small tornadoes off the trailing edge of the wingtip, also known as wingtip vortices). Note that the 757 used to be a "heavy," for call sign purposes, even though its max weight is around 255,000 lbs, since it generated extremely dangerous vortices, more so than many others near its weight. I don't know the current status of that, since some are saying it's no longer required for them to say "heavy."

 

I've seen things that say something like 'Such "heavy" aircraft over 136 t create wake turbulence from the wings.' (from Wikipedia), but the truth is that all aircraft (yes, even gliders) generate wake turbulence, just not with the strength that larger aircraft do.

 

As examples, most private pilots and above are familiar with "hitting your propwash" in a level turn, which is actually hitting your wake turbulence, but it's just a light bump. In my younger days (1970 or so), I lived about 60 miles south of Chicago -- this was before the days of TCAs and, later, Class "B" airspace, and before wake turbulence was known as well as it is now (they were just starting to appreciate how much of a menace it was) -- and flew from the Joliet (JOT) airport. One day I was heading north (but still west of O'Hare) in a Musketeer at around 2500-3000 MSL when I saw a jet airliner go left to right a few miles in front of me, and what looked like a couple of thousand feet higher. As I got roughly under its path I felt a couple of sharp jolts a couple of seconds apart. I then realized I'd hit its wake turbulence, but fortunately perpindicular, not parallel, so I didn't have the problem of a rapid roll to go with that. And, as those vortices tend to do, they had descended to my altitude.

 

Note that the slower an aircraft goes (in other words, higher angle of attack), the worse the turbulence they generate.

 

A final anecdote: One day I was in a park just under the approach path to a runway at the old Stapleton airport in Denver. I watched a couple of airliners come over and land. Shortly after each came over, there was a loud rushing sound, and the trees on either side of the approach path (it had been cleared) waved wildly in the vortices from each of those jets.

 

Hope this helps clarify things.

 

Thanks. That's what I was looking for, but wasn't sure how to Google it like most things I want to know, and my Echo dot is flipping stupid. LOL

 

Yeah, I know about the wake turbulence planes can create and why they call them heavy. Just wanted to know the MTOW required for the designation.

 

I didn't know a slower aircraft would produce more wake turbulence. Interesting.

 

You said you felt wake turbulence West of 'O'scare.' Was there not any real safe altitude restrictions back then to make sure you didn't suffer from another plane's wake turbulence? I mean, you say wake turbulence descends so I can only imagine that the FAA has limits on vertical height stacking with traffic.

 

I remember right after 9/11 (could have been just a month or so) that a plane came crashing down in a New York or New Jersey neighborhood. The ultimate cause of this accident was due to the wake turbulence from the previous aircraft that took off (and I think) over compensation with the rudder. Since then I believe now the FAA has mandated that tower keep planes on take off separated at a greater distance. Pretty scary stuff, and if I was a commercial pilot, I'd probably allow a few more seconds before I took off with a plane that just took off prior knowing full well about the wake turbulence possibility. I like to read about aircraft accidents on Wikipedia and in Plane & Pilot so that I can learn from the mistakes and not repeat them if I were able to fly. I also take it into account as part of a more realistic atmosphere in the Sim.

 

I was born in Arlington Heights, IL. And my parents lived in a neighborhood prior to them getting their first apartment in Wooddale. The house is so close to 'O'scare' that you could see the passengers in the plane's windows on landing going East. Having been back to the Chicago area a few times in my life it's amazing to see all of the planes flying over head. One right after another, and another. One thing I thought was hilarious was that the flipping airport had a Chicago hot dog stand there in the terminal. LOL! I can still smell that mustard. Chicago has some of the best damn food EVER! Love my Italian beefs, Chicago hotdogs and gyros. I've been to Portillos a number of times, but I hear Al's is even better. But I've never been there. I still have family that live in Chicago. And my great uncle who was a pretty well off real estate lawyer has his large arrowhead collection at the Field Museum. Never been there though. Only Science & Industry.

 

Anyway... Since I live in Colorado as well, I've only seen Stapleton once. Been to DIA many times. I practically know that airport inside out and its runways. Well, KDEN is my second home base with KFNL being my 1st home base. I bought the Flightbeam KDEN add-on and it even has the hotel inclusion next to the main terminal or what ever you call it. The giant 'mountain-like' white tents. Probably one of the most unique airports I've seen. O'hare has like an industrial feel to it. Which to me makes sense giving the fact there's a crap ton of manufacturers out there like Snapple, Motorola, etc. In fact, the Snapple plant is right near where my grandpa is buried and O'hare is just a stone's throw from there.

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I remember right after 9/11 (could have been just a month or so) that a plane came crashing down in a New York or New Jersey neighborhood. The ultimate cause of this accident was due to the wake turbulence from the previous aircraft that took off (and I think) over compensation with the rudder.

If that's the one I'm thinking of, it was a UAL 737. It was found during the crash analysis by the NTSB that the copilot had the yoke at the time. He caught some wake turbulence, yes, but he tried to correct with too much rudder. At that time, the 737's had a small problem with the hydraulic valve that ran the rudder's hyds. It could go JUST far enough in it's throw that it would open a port to full throw the rudder to the opposite side, and lock it there. The pilot and co-pilot had no CRM, or unusual attitude recovery training. They didn't know how to compensate for the stuck rudder, and didn't realize which way the rudder had thrown. The plane went inverted, and, since they were pulling up, it dove into the deck. Some rumors have it that the copilot froze on the controls, pulling up, and pushing the rudder pedals the wrong way, but there's no confirmation I know of.

 

I like to read about aircraft accidents on Wikipedia and in Plane & Pilot so that I can learn from the mistakes and not repeat them if I were able to fly. I also take it into account as part of a more realistic atmosphere in the Sim.

Another fantastic source of that information is the Navy/MC's Approach magazine. It's a monthly, or bi-monthly, magazine. You have to do a little looking to find it, because they keep altering the ISP address of the library, but a little Googling will dig out the right addy. Sometimes you have to kind-of get in the front door, rather than straight to the library, but it's pretty easy over all.

Fantastic, mostly written by the pilots themselves, assuming they survive. Very few posthumous stories, although reading some of them, I'm surprized there aren't more of them!

 

Pat☺

[sIGPIC][/sIGPIC]

Had a thought...then there was the smell of something burning, and sparks, and then a big fire, and then the lights went out! I guess I better not do that again!

Sgt, USMC, 10 years proud service, Inactive reserve now :D

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That's what it was. The 587 number rings a bell now. https://en.wikipedia.org/wiki/American_Airlines_Flight_587

 

I could have sworn that the FAA recommended that aircraft were to hold a certain amount of time before takeoff when another aircraft took off before them due to this one accident. But there's no mention of that in the Wikipedia article. Something interesting is that it states the flight data recorder cut off due to lose of the engines. I always thought that like the cockpit voice recorder, it too would have a battery backup. Seems prudent. Or at least tie it in with the RAT as well.

 

You can tell you're an aviation nerd when you've watched three of the shows that cover this accident listed in the article.

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