# Practice English Speaking&Listening with: WHY do pilots say HEAVY? Wake Turbulence EXPLAINED BY CAPTAIN JOE

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Speedbird 2276 heavy wind three six zero at five runway seven left at alpha East, cleared for take-off

Cleared for takeoff zero seven left

Speedbird 2276 HEAVY

Dear friends and followers,

welcome back to my channel and to a great ATC related video as many of you have questioned,

Why do pilots say heavy at the end of their call sign as you just heard in the intro and what the heavy

callsign has to do with roof tiles. So let's get started. [music].

Now I'm pretty sure many of you have seen airplanes approaching airports all lined up like pearls on a necklace

Coming in one by one. Now,

they seem to be all flying in a safe distance from each other as this is the work of the approach

controller. Now he makes sure that the airplanes have enough separation from each other by vectoring them with given headings and

controlling their speed onto the instrument landing system.

Now the planes land as such that they have

enough time to vacate the runway at the suitable taxiway before the next plane comes to land.

Now as you can see here in this video an Airbus

A320 is just landing and you can already spot the next airplane, a Boeing 777, right behind it.

But the reason for this separation is not just the time to vacate the runway,

actually the primary reason is wake turbulence avoidance.

So what is a wake turbulence? Now, a wake turbulence or wing vortex occurs when wing is generating lift.

Now, if air below the wing is drawn around the wingtip into the region above the wing

by the lower pressure on the upper side of the wing

Causing a vortex to trail from each wingtip. Now the strength of the wingtip vortex is

determined primarily by the weight the

airspeed and the angle of attack of the aircraft. Now the higher the angle of attack and the

heavier the plane, the stronger the wake turbulence becomes. Now this short video here perfectly shows the generation of wake turbulence

but keep in mind this is only an ultralight airplane with a maximum weight of roughly 450 kilos,

but it's impressive how quickly the wakes appear. So imagine the wake turbulence a Boeing 747

generates with a maximum landing weight of 302 tonnes and wake turbulence are a

serious threat for the preceding plane.

Nasty down drafts and sudden excessive roll rates get the plane in an upset state

you do not want to experience on short final as a pilot or as a passenger.

Numerous testing has shown that wingtip vortices have an estimate sink rate of

400 feet per minute and come to rest at 800 feet below the airplane's flight path

where it is considered safe to fly across the dissipating wake.

So let's determine the minimum separation needed between two Airbus A320's

now we are definitely going to need two minutes and that is the time it takes to wake to descend 800 feet and

Two minutes at an average approach speed of 130 knots results in

4.3 nautical miles minimum separation distance now at 64.5 times maximum landing weight the

A320 is not the heaviest aircraft out there. So the ICAO came up with the wake turbulence

Weight categories now write this down because these numbers will be in your HPL exam.

Category L is for light weight - So any plane up to 7 tons or less.

category M for medium is for 7 tonnes up to a hundred and thirty six tons and

Anything heavier than that is categorized as heavy, but as usual there is an exception

So listen to the ATC call of my dear friend Paulo Alexander

Bukarest control, very good morning Quatar 13VP "SUPER" at level 390

As he flies the Airbus A380 ICAO had to introduce a new category for aircrafts with a take of weight up to

560 tonnes named

Super, so as mentioned a minute ago

the heavier the plane the larger and more intense the wakes are the more

separation is needed between the planes. Now if we come back to our first video you see the British Airways 777 has just landed

categorized as heavy followed by a medium category Airbus A320 now you can see there's a

significant larger gap between both airplanes and as ICAO regulates if a medium follows a heavy aircraft

Their minimum separation has to be 5 nautical miles now

This can go up to 8 nautical miles for instances a light aircraft like a Cessna Caravan follows an Airbus

A380. But if a heavy aircraft follows a lighter aircraft

they aren't affected as much by the wake due to the

Actual heavier weight and are safe at a distance of 4 nautical miles.

But it's not just the ATC controllers responsibility to vector you accordingly

you as a pilot have to keep the necessary distance in order to not get into the wake turbulence of the

preceding aircraft.

But how do you know as the pilot? What type of plane is ahead of you?

And this brings us to the main question of the video. That's the reason why

pilots flying airplanes categorized as heavy creating the more severe turbulence

mentioned their category at the end of their call sign

So as a pilot, you should pay close attention who you following

Especially when intercepting the ILS at the lower altitude than your preceding airplane and wakes aren't just a threat during

landing; a similar procedure applies during takeoff now very often

you can see a heavy Airbus A330

departing and then a smaller Boeing

737 or Airbus A320 wait on the runway for their takeoff clearance and the waiting period is a

safety measure to let the wake turbulence

dissipate before the lighter aircraft commences takeoff. Now you say that's not true

I've seen turbo props rolling down a runway right after a heavy has taken off.

Yes, that's true this can happen but there's something very important to keep in mind

Wake turbulence as mentioned before are first

Generated when the plane rotates meaning creating lifts over the wing

so if the turboprop pilot closely monitored the lift of point of the preceding plane and

Knows his takeoff roll will be shorter

He can immediately commence takeoff as he will fly over the flight path and wakes of the preceding plane also

During cruise flying through the contrail of an aircraft can get very turbulent

So avoid flying through those especially with passengers in point

Now these strong rotors upon landing are no joke

They are so powerful that houses close to airports have to have special roof tiles as in the past

They have caused many damages

Especially if you're in flight school and feel the need to fly to a big international

Airport for a low approach with your little Cessna and besides the tower control that will warn you about the wakes. Keep a safe distance

Because getting flipped over by a wake isn't cool at all. And if it doesn't feel safe you canalways

Go aroundalso be aware of hovering helicopters in the vicinity of the runway

There wakes can be as powerful as a medium categorized aircraft. And by the way speaking of flight school

Have we ever thought why a glider plane always flies a little higher than its preceding tow plane

although Concorde fell into the category of a medium-weight

Aircraft due to her excessive angle of attack upon landing

Her delta wing created wake turbulence as strong and as dangerous as the ones of a jumbo and therefore the pilots had to say

speedbird Concorde too heavy!

God, I miss this plane

That's it for today

Thank you very much for your time, before make a touch and go up Instagram account and mention your wake category.

Hit the subscribe button and notification bell and don't forget a good pilot is always learning. See you next week. Wish me over and out, your Captain Joe.

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