The ATC Simulator handbook
Glossary
The phonetic alphabet, the radio number words and the working vocabulary of air traffic control, each with its spoken example.
The phonetic alphabet
Single letters are easy to mishear on a busy frequency, so aviation spells them with words. Two of the spellings look odd on purpose: Alfa rather than Alpha, and Juliett with two t's, so that speakers of other languages pronounce them the same way.
- A
Alfa
- B
Bravo
- C
Charlie
- D
Delta
- E
Echo
- F
Foxtrot
- G
Golf
- H
Hotel
- I
India
- J
Juliett
- K
Kilo
- L
Lima
- M
Mike
- N
November
- O
Oscar
- P
Papa
- Q
Quebec
- R
Romeo
- S
Sierra
- T
Tango
- U
Uniform
- V
Victor
- W
Whiskey
- X
X-ray
- Y
Yankee
- Z
Zulu
Numbers on the radio
Digits are normally spoken one at a time. Round hundreds and thousands in altitudes, and airline flight numbers, are spoken as groups. Four digits have changed pronunciations so they cannot be confused with each other on a noisy radio.
- 0
zero
- 1
one
- 2
two
- 3
tree
Spoken tree so it cannot melt into free or be lost to a th- sound a non-native speaker does not have.
- 4
fower
Two syllables, so it cannot be confused with for.
- 5
fife
The soft v ending of five drops out under static, so the spoken form ends in a hard f instead.
- 6
six
- 7
seven
- 8
eight
- 9
niner
Two syllables, so it cannot be confused with five, or with the German nein.
Words that do work
Each of these radio words has one fixed meaning. Using one loosely is a common cause of misunderstandings.
- Roger Roger.
I received your whole transmission. It does not mean yes, and it is not a readback.
- Wilco Wilco.
I received your instruction and will comply. Stronger than roger; still not a readback of the numbers.
- Affirmative Affirmative.
Yes. US practice keeps the full word; ICAO shortened it to affirm so a clipped transmission cannot be heard as negative.
- Negative Negative.
No.
- Unable Unable.
I cannot comply with that instruction. Information, not defiance; it forces a new plan, fast.
- Say again Say again for American Two One Five.
Repeat your transmission. The phrase is standard, in place of sorry or what, so it works when nothing else does.
- Standby American Two One Five, standby.
Wait, something higher priority comes first; call again if the delay runs long. A standby is not a clearance and not an answer.
- Radar contact American Two One Five, radar contact.
I have identified you on my display and will provide radar flight following. Said when identification is established, and the pilot can stop making position reports.
- Readback
The pilot repeating a clearance or instruction back so the controller can verify it was received correctly.
- Hearback
The controller's half of the loop: actually listening to the readback and catching the one that came back wrong.
- Heavy United Four Heavy, Bayview Approach.
A wake-turbulence class carried in the callsign of aircraft able to take off at 300,000 pounds or more, because the wake they leave behind is a hazard to whoever follows.
- Mayday Mayday, mayday, mayday.
The distress call: the aircraft is in grave and imminent danger and needs priority over everything.
- Pan-pan Pan-pan, pan-pan, pan-pan.
The urgency call: a serious problem, but not yet a distress. It outranks everything except a mayday.
In the tower
These are the tower's working phrases from chapters ten through thirteen. Most of them are clearances, and each one has a single fixed meaning.
- Local control
The tower position that owns the active runway and the sky immediately around it; Tower on the radio. Every use of the runway happens on its say-so.
- Ground control
The tower position that owns the taxiways. It delivers departures to the holding point and takes arrivals back once they are clear of the runway.
- Holding point
The marked position at the runway entrance where a departure waits for its clearance. Crossing the marking without one is a runway incursion.
- Line up and wait Runway two five right, line up and wait.
Taxi onto the runway and stop on the centerline, staged for an imminent departure. It is not a takeoff clearance, and pilots treat the difference as absolute.
- Cleared for takeoff Runway two five right, wind two five zero at eight, cleared for takeoff.
The runway is yours to fly from. Runway number first, then the wind, then the clearance, always in that order.
- Cleared to land Runway two five right, cleared to land.
The runway is yours to land on. It may be issued while the aircraft ahead is still clearing, on the judgement that the runway will be free at the threshold.
- Continue approach Continue approach, wind two five zero degrees eight knots.
Keep flying the approach; the landing clearance is still to come. It authorizes nothing about the runway.
- Go around Go around, I say again, go around.
Break off the approach, climb, and fly the missed approach. The arrival's escape when the runway stops resolving.
- Hold short
Stop before the runway's holding position marking and do not enter. Hold short instructions must be read back.
- Vacate
Leave the runway. An aircraft is clear of the runway once all of it is past the holding position marking, and the pilot is the one who determines it.
- Runway incursion
Anything on protected runway surface that should not be there: an aircraft past its hold line, a vehicle without approval. The accident category towers exist to prevent.
ATC procedures and phraseology are based on FAA Order JO 7110.65BB. This game is not affiliated with, endorsed by, or a product of the FAA, and is not for real-world training or operational use.