Lateral

Command	Short	Pad signs	Pad digits	Meaning
`t <HDG>`	`t<HDG>`	`*<HDG>`		Turn to a heading the shorter way
`tl <HDG>`	`tl<HDG>`	`*-<HDG>`	`4<HDG>`	Turn left onto a heading, even if right is shorter
`tr <HDG>`	`tr<HDG>`	`*+<HDG>`	`6<HDG>`	Turn right onto a heading, even if left is shorter
`tl by <DEG> / tr by <DEG>`	`tlb<DEG> / trb<DEG>`	`-<DEG> / +<DEG>`		Turn a number of degrees from the present heading, 1 to 180
`dct <FIX>`		`*<FIX>`		Direct to a fix
`route <FIX>,<FIX>,...`	`rt <FIX>,<FIX>,...`	`*<FIX>,<FIX>,...`		A sequence of fixes, flown in order. Needs at least two; for a single fix use `dct`
`present heading`	`ph`	`*`		Fly present heading: drop the lateral plan and hold the current heading
`orbit left / orbit right`	`ol / or`	`-- / ++`		Fly one full circle, then carry on with whatever the aircraft was already doing

A direct-to resolves globally; where an ident exists more than once, the nearest wins. If the fix is already on the aircraft's cleared route or transition, the aircraft shortcuts to it and carries on with the rest of the route. If it is not, the rest of the route is dropped.

A route's fixes are joined with commas and no spaces, in every spelling. route MIQ,ROKIL,ANELA is a route; route MIQ ROKIL ANELA is refused as unrecognised. The route is the one command that takes a list of any length, and a fix name can look exactly like a command (D2 is a fix near Ajaccio and a descent, HAAKE is a fix and a hold over AAKE), so a list with spaces in it had no end the server could find: it stopped the list wherever a fix happened to read as a command, and either refused a good route or flew a clearance nobody gave. With the commas the list is one word, the space after it is where the next command begins, and every fix name is safe inside it:

DLH123, route MIQ,HAAKE,ROKIL d100

That is three fixes and a descent. A route pasted from a flight plan needs its spaces replaced by commas first.

A heading stays in force until you replace it with another lateral instruction. An altitude or a speed given afterwards rides along with it and does not end it, so an aircraft that reaches its cleared level halfway through a long turn keeps turning to the heading you gave.

An orbit is an interruption, not a new plan. The aircraft flies one full circle in the direction you name and then carries on with whatever it was doing before: a heading, a route, or an arrival, picked up where it left off. There is no command to end one, and none is needed.

A second orbit replaces the one being flown rather than queueing behind it, so you never stack circles by re-typing. Giving the opposite direction reverses the turn, and either way the aircraft starts a fresh circle from the heading it is on when it takes the new instruction, not from the one it started the first circle on. To end an orbit early, give it something else to do: a heading, a direct, or an approach clearance.

How long the circle takes depends on the aircraft and how fast it is going, not on a fixed rate. An A320 at 180 knots comes round in just over two and a half minutes; the same aircraft at 250 knots takes about four. A light aircraft turns no faster than three degrees per second, so its circle runs a little over two minutes. Higher up the turn is gentler again, so the same aircraft orbiting in the cruise takes longer than it would in the descent. Judge the spacing you are buying against the aircraft you are turning, not against the last one.

An orbit leaves an approach clearance armed

An aircraft cannot fly a circle and follow a localiser at the same time, so an aircraft that is already established leaves the localiser for the circle, and the readback says so. The clearance itself stands, as it does through a heading: the aircraft flies the circle without joining the localiser and takes the beam again once the circle is behind it, with nothing further from you. orbit right clr ils 26L on one line is the same thing in one breath.

Why dct has no short form

It used to shorten to d, the same letter as descend, and the two were told apart only by whether the argument began with a letter or a digit. Three characters is short enough, and the one you save is not worth the moment of doubt. d ERNAS is refused.