TWRCTRL

THE JOB

You work TOWER and GROUND together. Click an aircraft on the map, or its strip, to fill the callsign, then type the clearance into RADIO and press Enter.

The dropdown lists the legal next words: arrows to pick, Enter to send. The route draws on the map before the clearance goes out, flashing while it is incomplete and solid once it reaches the target.

INSTRUCTION SHAPE

Every clearance is the same three slots: [CALLSIGN] [TARGET] [PATH]. TARGET is where the clearance ends: a runway hold, a gate, a stand, or a pushback facing. PATH is the vias in the order they are flown, starting with the one the aircraft is already on.

Taxiway letters and runway numbers are the ones painted on the field. SHOW TAXIWAYS in the top right corner lights them up. Where two paths reach the same parking, swapping the last taxiway sends the route the other way, and both still end in the same place.

ICE306 19 K E N: Taxi to the hold of runway 19 via K, then E, then N. They hold short and do not enter. That entry must have the takeoff run they need; otherwise dest -19 to hold short (or cross).
ICE307 GATE 14 N E: Taxi in to gate 14 via N then E. Use STAND when that is what the strip shows.
ICE306 PSHBK SE: Push back to face southeast. A pushback has no path.

DEPARTURE FLOW

Gate to airborne is three clearances.

HOLD stops them where they stand, mid-push or mid-taxi. After a hold short, RESUME continues the rest of the clearance.

1PSHBK SE Push back. The compass point is the facing they stop in, not the direction of travel. N / NE / E / SE / S / SW / W / NW.
219 Q N Taxi to the hold of runway 19 via Q then N. They stop at the holding point.
319 CLRD TAKEOFF Cleared for takeoff. Issue it once they are holding at that end, or while they are still taxiing to it. Check the strip is empty and they have the length they need from that entry.

ARRIVAL FLOW

An inbound is three clearances, from final to parking.

If the approach is not working, GO AROUND. MIN SPEED then RESUME SPEED buys spacing on final.

119 CLRD LAND Cleared to land. Issue it while they are inbound on final for that runway.
2VCTE Q Vacate via taxiway Q while they roll. Add LEFT or RIGHT when the same letter exists on both sides of the strip.
3GATE 14 Q N Taxi to the assigned parking via Q then N. CROSS a runway in PATH if the route goes over one.

HOLD SHORT AND PASS

Prefix a taxiway or runway with - or -- to stop short of it. Type the dash in the PATH slot, or the TARGET slot, and the dropdown switches to HOLD SHORT / HOLD PAST.

PASS is not a destination of its own. After a taxiway hold short it gives way to whoever is rolling that taxiway, then continues onto it.

-Q: Stop before Q. RESUME then enters Q.
--Q: Stop at the first Q intersection and stay off Q.
-19: Hold short of runway 19 mid-route. Same as using 19 as target, but later on the path.
19 -Q PASS: Hold short of Q, let the traffic go, then join Q toward 19.

LINE UP BEHIND

19 LINE UP BHND holds the aircraft at the entry until the traffic ahead is out of the way, then lines it up. That is an arrival rolling past the entry, or a departure moving away from the line up point, whichever is the case at the time. Long form: BEHIND.

There has to be traffic to be behind, or the command will not take.

CROSSING A RUNWAY

CROSS 19 authorises the taxiways and fillets over that strip. BKTRK 19 is CROSS plus travelling the centreline, a backtrack.

Without one or the other, the hold line blocks the path and they stop there.

SPLIT RUNWAY OPERATIONS

There is no command for this. You choose it by clearing landings and takeoffs on more than one strip. On a crossing layout (BIKF 10/28 × 01/19) that only pays if you can keep the intersection empty.

If you cannot protect the junction, keep a single runway. More traffic is not a reason to split.

WIND: ATIS / METAR. A strong wind on one axis makes the other strip a tailwind or a heavy crosswind. If only one pair of ends really works, stay on that pair.
CROSSING: Never two movements in the junction at once. Hold one short of the crossing, or wait with margin until the arrival has vacated past it, or the departure is airborne and past it.
SPACING: A stream of inbounds on one strip leaves no gap to launch on the other. Split when mixed traffic would otherwise queue and the next arrival is far enough that the crossing will be clear.
TAXI: Two active strips usually means more runway crossings. Budget CROSS and hold shorts on the ground routes, or the air picture looks fine while the apron locks up.

COMMAND LIST

Every line starts with the callsign. It is already filled in if you clicked the aircraft or its strip.

PSHBK N: Pushback. The cardinal is the facing at the stop. The only clearance from a gate.
PSHBK GATE: The tug pulls back into the stand. Only after a HOLD mid-push.
19: Taxi to the hold of runway 19 for departure. Too short from that entry still routes, with remaining/need in red — the clearance will not send. Use -19 to hold short (or cross).
GATE 14 / STAND 63: Taxi to that parking position.
Q N: PATH vias. Name the taxiway under the nose when it is a proper run.
-Q / --Q: Hold short of Q / hold at the first Q intersection and stay off Q.
-19: Hold short of runway 19 on the path.
PASS: After a taxiway hold: give way, then continue onto that taxiway.
CROSS 19: Cross runway 19 on taxiways and fillets.
BKTRK 19: Cross plus travel the runway centreline (backtrack).
19 LINE UP: Enter the runway and wait.
19 LINE UP BHND: Line up once the traffic ahead has rolled past or moved off the entry.
19 CLRD TAKEOFF: Cleared for takeoff. Long form: CLEARED TAKEOFF.
19 CLRD LAND: Cleared to land. Long form: CLEARED LAND.
VCTE Q [LEFT|RIGHT]: Vacate via that exit. Long form: VACATE.
HOLD: Stop where they stand. Also stops a push or a tow. Before the takeoff roll, cancels takeoff clearance.
LINE UP: After takeoff clearance, before the roll: cancel takeoff and line up and wait.
RESUME: Continue past the current hold short.
ABORT: Reject a takeoff that is already rolling.
GO AROUND: Discontinue the approach.
MIN SPEED: Minimum approach speed. RESUME SPEED to go back.
TOW 50: Tow back up to that many metres (max 300), along the trail they came.