Some airplane pilot jargon: "Rotate", "Heavy"

[Stephen Tashi]

Having watched slew of documentaries about (civilian) air crashes, I wonder about some oft-heard jargon.

A airline flight is often referred to with the adjective "heavy". For example, "AA 191 Heavy". What does "heavy" indicate?

During takeoff, the monitoring pilot says "V-1" to indicate reaching a speed where a takeoff cannot be aborted and says "Rotate" when the plane should leave the ground - or something like that. I'm curious about the origin of "Rotate". How did that term come to be used instead of "take off"?

 

[Borek]

I think "rotate" means rotation around pitch axis (so just "nose up").

 

[Ibix]

Heavy means what it says - your aircraft is a big heavy one and requires some extra room behind it because the wake turbulence it generates might affect other flights. From here,

The FAA requires any aircraft with a maximum takeoff weight in excess of 300,000lbs to use the term "heavy." This includes Boeing 747, 767, 777, and 787 aircraft. Airbus A300, A310, A330, A340, and A350 aircraft must also use this term. When the gigantic A380 was introduced, the FAA created its own category for the aircraft: "super."

 

[davenn]

A airline flight is often referred to with the adjective "heavy". For example, "AA 191 Heavy". What does "heavy" indicate?

Heavy means what it says - your aircraft is a big heavy one and requires some extra room behind it because the wake turbulence it generates might affect other flights. From here,

I have also seen/heard that used when the aircraft is fully laden with fuel, as it usually would be on takeoff.

 

[Lnewqban]

Heavy is an aircraft class regarding take off weight.
Copied from
https://www.faa.gov/air_traffic/publications/media/pcg_4-03-14.pdf

"AIRCRAFT CLASSES− For the purposes of Wake Turbulence Separation Minima, ATC classifies aircraft as Heavy, Large, and Small as follows:

a. Heavy− Aircraft capable of takeoff weights of 300,000 pounds or more whether or not they are operating at this weight during a particular phase of flight.

b. Large− Aircraft of more than 41,000 pounds, maximum certificated takeoff weight, up to but not including 300,000 pounds.

c. Small− Aircraft of 41,000 pounds or less maximum certificated takeoff weight."

Rotation is a pilot-induced change of pitch, via elevator, that increases the angle of attack of the wings at the proper speed (too soon increases drag, too much could induce a tail strike).
Rotation does not mean inmediate take-off.
Copied from
https://en.m.wikipedia.org/wiki/Rotation_(aeronautics)

"After rotation the aircraft continues to accelerate until it reaches its liftoff speed VLO at which point it leaves the runway. Over-rotation can cause a tailstrike in which case damage to the underside of the tail is prevented by a tail bumper."

Combining both terms:
Copied from
https://en.m.wikipedia.org/wiki/Wake_turbulence

"An aircraft of a lower wake vortex category must not be allowed to take off less than two minutes behind an aircraft of a higher wake vortex category. If the following aircraft does not start its take off roll from the same point as the preceding aircraft, this is increased to three minutes. To put this more generally, an aircraft is usually safer if it is airborne before the rotation point of the airplane that took off before it. However, care must be taken to stay upwind (or otherwise away) from any vortices that were generated by the previous aircraft."

 

[Filip Larsen]

There seems to be a bit confusion in this thread about the word "rotate".

Rotate speed is a precalculated speed (like the other speeds used for callouts) during the takeoff roll at which the the pilot not flying, i.e. the pilot who during the roll has his gaze inside the cockpit at the instruments, makes a "rotate" callout to the pilot flying, i.e. pilot who has his hands on the controls and his gaze outside away from the airspeed indicator, that he or she should initiate the pitch up to rotate the aircraft from rolling with nose wheel on the ground to having a specific pitch so the aircraft can become airborne. If you rotate too early (i.e. rotate at low airspeed) there is risk of tail strike if the rotation is continued (because the speed is not yet high enough for the aircraft to become airborne) and it will also make the takeoff roll longer due to lower acceleration from increased drag.

The normal sequence of callouts are "V1" (the aircraft now has a speed where it is committed to becoming airborne and pilot flying takes his hands of the throttle), "rotate", and finally "V2" signaling the aircraft now has reached the predetermined departure airspeed and more pitch up or throttle down can be done while still maintaining a safe climb. For longer runways (relative to the aircraft type and weight) the rotate may come right after V1.

See also https://en.wikipedia.org/wiki/V_speeds for more interesting airspeeds in avaiation.