ATC(6) ATC(6)
NAME
atc - air traffic controller
SYNOPSIS
/usr/games/atc
DESCRIPTION
Atc presents air traffic on a cursor-controlled screen. As
the controller, you must shepherd it safely through the air
space. At the beginning of the game atc displays the
takeoff/landing direction for each airport and prompts for
the game duration with:
< > enter a number from 16 simulated minutes (hard) to 99
(easier)
Options are
-u=file take airspace description from file
-a=name use the named airspace; default is `Apple1'
-s=seed a number for seeding a 32-bit random number genera-
tor
-t=time preset the game duration
-p=file save the play of the game in the named file
-m=file play a `movie' of the saved game
ATC(6) ATC(6)
The initial display of a typical airspace looks like this:
.0 . . . . . . 1 . . . . . . . . . . . . . .
.. , . . . . . , . . . . . . . . . . . . . .
.. . , . . . . , . . . . . . . . . . . . . 2
.. . . , . . . , . . . . . . . . . . . . , .
.. . . . , . . , . . . . . . . . . . . , . .
.. . . . . , . , . . . . . . . . . . , . . .
.. . . . . . , , . . . . . . . . . , . . . .
6, , , , , , , * , , , , , , , , , , , , , 3
.. . . . . . . , , . . . . . . , . . . . . .
.. . . . . . . , . , . . . . , . . . . . . .
.. . . . . . . , . . , . . % . . . . . . . .
.. . . . . . . , . . . , , . . . . . . . . .
.. . . . . . . , . . . , , . . . . . . . . .
.. . . . . . . , . . , . . , . . . . . . . .
.. . . . . . . , . , . . . . , . . . . . . .
.. . . . . . . , , . . . . . . , . . . . . .
4, , , , , , , * , , , , , # , , , , , , , 5
.. . . . . . , , . . . . . . . . . , . . . .
.. . . . . , . , . . . . . . . . . . , . . .
.. . . . , . . , . . . . . . . . . . . , . .
.. . . , . . . , . . . . . . . . . . . . , .
.. . , . . . . , . . . . . . . . . . . . . 9
.. 7 . . . . . 8 . . . . . . . . . . . . . .
% and # denote airports, * and ! denote navigational aids
(navaids), and commas denote airways that link entry/exit
`fixes', airports, and navaids. Dots are separated by one
mile, horizontally, vertically, and diagonally. An airplane
appears as a letter followed by its height in thousands of
feet.
There are two kinds of planes: jets flying 1 mile per tick
(15 seconds) and props flying 1/2 mile per tick.
You must prevent various misfortunes. Running out of fuel
is serious. So is a close encounter - less than 3 miles
horizontal separation at a given altitude. A plane changing
altitude is considered to be at both its old and new alti-
tudes. A `boundary error', leaving the airspace at the
wrong place, not on an airway, or at the wrong height, is
also serious, but not as likely to be fatal.
The right side of the screen shows flight plans. A typical
flight strip looks like:
Fj 7->3 4 NE +
The first letter is the aircraft ID, the next letter is `j'
for jet or `p' for prop. The next field gives the plane's
intentions: this one is entering at (or is now at) fix 7 and
leaving at fix 3. The origin character tells where the
plane is (or will be when it enters), the destination is a
ATC(6) ATC(6)
fix it wishes to go to. (It will, however, continue on a
straight path unless instructed otherwise.) Next is the
altitude, in this case 4000 feet. The bearing is a compass
direction: N, NE, E, etc. The final character is the amount
of fuel left, `+' for more than 10 minutes, otherwise the
number of minutes of fuel remaining. Jets begin with 15
minutes of fuel, props 21.
At the top of the flight plans are listed planes that will
appear in the next minute, preceded by how many ticks (0-4)
they are away. Planes may be cleared for takeoff as soon as
they are listed.
Commands are terminated by <RETURN>. <BACK SPACE> may be
used to correct errors. The following kinds of commands can
be issued.
$ End the game (game normally ends after 26 planes)
W Print flight plan for airplane W
XA3 X will change altitude to 3000 feet
QA0 Q will land (go to 0 feet altitude)
HRE H will turn right until it is heading east
ALNW A will turn left until it is heading northwest
CTS C will turn south through the smallest angle
T*7 T will take exit bearing for fix 7 at next navaid
P*% P will take landing bearing for % at next navaid
DH D will circle (hold) at next navaid
MR0 Abort pending hold, clearance, or turn for plane M
J? Cancel delayed commands for J
<SPACE>
Speed up the game by advancing 15 seconds
Climbing/descending. Planes climb or descend 1000 feet per
mile. Climbing from 0 is a takeoff; descending to 0 is a
landing. The takeoff/landing direction for each airport is
given. A landing airplane must reach altitude 0 headed in
the right direction 1 mile before the runway. No further
commands may be given after a descent to 0, as control then
rests with the tower. If a plane lands from the wrong
direction, it will climb to 1000 feet and issue a `go
around' error. While changing altitude, a flight strip
reads like
Dp :->2 7v3 S 9
which means at 7000 feet descending to 3000.
Turning. Planes turn 45 degrees per mile. Turns may be left
(L) right (R) or to a specified direction (T). Thus `ULNE'
tells the pilot of plane U to turn to his left until he is
heading northeast. Changes of direction are indicated in
the flight strip:
Nj :->5 5 S r W +
indicates that jet N is heading south, and will turn 90
ATC(6) ATC(6)
degrees to the right. To cancel the remaining part of a
turn, give the command (for plane N) `NR0'.
Navaids. A plane may be directed to turn at a navaid or hold
(circle) there, Thus command `AH' holds plane A at the next
navaid. The flight strip for a plane that is to hold looks
like
Ap :->2 5 S * 7
During the hold, the `*' will become `h'. Every incoming
plane that will be landing holds at a navaid unless the con-
troller gives it other instructions.
The command `*' clears a plane to turn sharply to any known
fix at the next navaid. The flight strip for a plane
cleared through a navaid (to fix 5, for example) looks like:
Hj .->2 5 S *5 +
A holding aircraft given a clearance will continue around to
the navaid, then immediately assume the specified bearing.
Turns cancel clearances.
Delayed commands. Commands of the form
@<location>,<command>[,<command> ...]
stack up activities. A location may be any fix or a point
offset from a fix, e.g.
@#sw3s2,ARE
which means at the point which can be reached by going three
miles SW from airport #, then two miles S, plane A should
begin a right turn until heading E. The information command
shows all delayed commands pending for that plane. Note
that delayed commands allow one to specify actions more than
one navaid ahead.