Aeronautical Information Manual (AIM), page 246

Index   245 -- Page 246 -- 247


1. Areas of precipitation (can be reduced by CP)

2. Arrival/departure tabular list

3. Trackball (control) position symbol (A)

4. Airway (lines are sometimes deleted in part)

5. Radar limit line for control

6. Obstruction (video map)

7. Primary radar returns of obstacles or terrain (can be
removed by MTI)

8. Satellite airports

9. Runway centerlines (marks and spaces indicate

10. Primary airport with parallel runways

11. Approach gates

12. Tracked target (primary and beacon target)

13. Control position symbol
14. Untracked target select code (monitored) with
Mode C readout of 5,000'

15. Untracked target without Mode C
16. Primary target
17. Beacon target only (secondary radar) (transponder)
18. Primary and beacon target
19. Leader line

20. Altitude Mode C readout is 6,000'
(Note: readouts may not be displayed because of
nonreceipt of beacon information, garbled beacon
signals, and flight plan data which is displayed
alternately with the altitude readout)

21. Ground speed readout is 240 knots
(Note: readouts may not be displayed because of a loss
of beacon signal, a controller alert that a pilot was
squawking emergency, radio failure, etc.)

22. Aircraft ID

23. Asterisk indicates a controller entry in Mode C
block. In this case 5,000' is entered and "05" would
alternate with Mode C readout.

24. Indicates heavy

25. "Low ALT" flashes to indicate when an aircraft's
predicted descent places the aircraft in an unsafe
proximity to terrain.
(Note: this feature does not function if the aircraft is not
squawking Mode C. When a helicopter or aircraft is
known to be operating below the lower safe limit, the

"low ALT" can be changed to "inhibit" and flashing


27. Airways

28. Primary target only

29. Nonmonitored. No Mode C (an asterisk would
indicate nonmonitored with Mode C)

30. Beacon target only (secondary radar based on
aircraft transponder)

31. Tracked target (primary and beacon target) control
position A

32. Aircraft is squawking emergency Code 7700 and is
nonmonitored, untracked, Mode C
33. Controller assigned runway 36 right alternates with
Mode C readout
(Note: a three letter identifier could also indicate the
arrival is at specific airport)
34. Ident flashes
35. Identing target blossoms
36. Untracked target identing on a selected code
37. Range marks (10 and 15 miles) (can be

38. Aircraft controlled by center

39. Targets in suspend status

40. Coast/suspend list (aircraft holding, temporary loss
of beacon/target, etc.)

41. Radio failure (emergency information)

42. Select beacon codes (being monitored)

43. General information (ATIS, runway, approach in

44. Altimeter setting

45. Time
46. System data area

4-5-4 Surveillance Systems

Page 246 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   245 -- Page 246 -- 247