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In Airplane there is a famous sequence:

Roger Murdock: Flight 2-0-9'er, you are cleared for take-off.
Captain Oveur: Roger!
Roger Murdock: Huh?
Tower voice: L.A. departure frequency, 123 point 9'er.
Captain Oveur: Roger!
Roger Murdock: Huh?
Victor Basta: Request vector, over.
Captain Oveur: What?
Tower voice: Flight 2-0-9'er cleared for vector 324.
Roger Murdock: We have clearance, Clarence.
Captain Oveur: Roger, Roger. What's our vector, Victor?
Tower voice: Tower's radio clearance, over!
Captain Oveur: That's Clarence Oveur. Over.

Regardless of the silly dialogue, when the captain asks "What's our vector, Victor?" what is he referring to? Does the scene refer to actual issues that one might discuss with air traffic control?

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3 Answers

A vector in general is defined by a position and a direction. For an airplane the position is the actual airplane and the direction is expressed as a bearing from magnetic north on a horizontal plane. In short, it is the direction you are flying or directed to be flying.

Example:

"Jetlink 1234, Cleveland Center, turn left heading 250 for traffic"

In which case the vector assigned by ATC is 250 degrees, or 20 degrees south of magnetic west.

To answer the question "What is our vector, Victor?", Victor should state the heading they have been assigned to fly from ATC.

An alternative question would be "What is your heading?" and then you would answer with the direction you are currently flying.

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A vector refers to a heading given by Air Traffic Control.

If you want to start learn aviation phraseology, there might be better sources out there:

There is some resemblance of reality but a number of things are mixed up.

Instead of replying with a 'roger', safety critical information is read back. This allows ATC to confirm that the instruction is clearly understood and if necessary they can correct errors.

The scene describes a take-off. In normal life, and assuming this is controlled airspace, the crew will like to know what to do after getting airborne before they start their take-off roll. There is no point in taking off if you are not allowed to fly in the airspace above the airport. That is why the departure clearance (here "vector 324") will be issued first. Vectors will be given as "heading". Very often the departure clearance is a standard route instead of vectors. (e.g. LEKKO two alpha departure). On large airports, departure clearances are given on a separate frequency to avoid congestion on the ground and tower frequencies.


Departure clearance

Tower: Fiction two zeroh niner, after departure, turn right heading three two four, climb and maintain six thousand feet.

FIC209: After departure heading three two five, 6000 ft.


Take-off clearance

Tower: Fiction two zeroh niner, runway 27, cleared for take-off

FIC209: Cleared for take-off runway 27, Fiction two zeroh niner.


Hand over to departure frequency

Tower: Fiction two zeroh niner, contact departure one two three decimal niner

FIC209: Departure on one two three dicimal niner, Fiction two zeroh niner.

FIC209: L.A. departure, Fiction two zeroh niner one thousand climbing six thousand.

Departure: Fiction two zeroh niner, radar contact, maintain present heading, climb and maintain ten thousand

FIC209: climbing ten thousand, Fiction two zeroh niner

Note that, when on the tower frequency, the words "take-off", and "cleared" are only used when the actual take-off clearance is given. This is to avoid (catastrophic) confusion. Since "After take-off" is cannot be used, instead the phrase "after departure" or "when airborne" is used.

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I'm a little late to this question, but want to add a little for people who aren't familiar with an aircraft heading.

As you said, the dialog is intentionally silly (and not entirely accurate) but most of what they are saying is loosely based on reality.

The short version is that a vector is where an air traffic controller is talking to an aircraft that is visible on radar, they know where they want the aircraft to go, and they assign a direction for them to fly in order to get there. This gets the aircraft where they want them without the aircraft needing to navigate on their own, and often allows them to take a "shortcut".


The longer version:

A vector as defined in the Pilot Controller Glossary is:

VECTOR - A heading issued to an aircraft to provide navigational guidance by radar.

(See ICAO term RADAR VECTORING.)

Of course, that leads to:

RADAR VECTORING [ICAO] - Provision of navigational guidance to aircraft in the form of specific headings, based on the use of radar.

Which then leads to:

HEADING - ...

Wait a minute... They don't define it! Okay, for those people that aren't pilots, a heading is the direction that an aircraft is flying. They are three digit numbers corresponding to the 360 degrees in a circle wrapped around a compass rose:

Compass Rose

While technically a heading is to the nearest degree, ATC will only ever assign headings rounded to the nearest 5 degrees. So, after North, the usable headings would be: 005, 010, 015, 020, etc. all the way around until you get to 355 and then 360. After that it wraps around again.

So if air traffic control wants you to fly North East, they will tell you to fly a heading of 045, South would be 180, and North would be 360 (fun fact, 000 is not a valid heading).

When ATC assigns a heading for a vector, they always have to be cognizant of what happens if the radio in the aircraft fails. Obviously they wouldn't expect you to fly straight ahead in that direction forever, so they include the end result of the vector in the clearance. Usually they also include the direction of the turn for those pilots that aren't very good determining directions. ;-) For example, they could say:

N1234, Turn left, fly heading 345, radar vectors to Fort Lauderdale International Airport.

In this case, they expect the aircraft to start a left turn, roll out on a heading of 345 and continue to fly straight until they get another clearance. If the radio failed, they would turn direct to the airport.

Sometimes they want the aircraft to fly a heading until they intercept a published portion of an instrument procedure. In this case, they would say something like:

N1234, fly heading 045 to intercept <the procedure>

The airplane would then fly the assigned heading until they get to the procedure and then fly the published procedure!

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