TM  1-1520-240-10            3-3-9 Table  3-3-2.   Computer-Display Unit Data Displays CENTER DISPLAY LEFT DISPLAY RIGHT DISPLAY SWITCH POSI- TION DATA RANGE DATA RANGE DATA RANGE WIND SP/DIR Windspeed 999 km/h Wind Direc- tion 359_ XTK/TKE Crosstrack Dis- tance Error L/R 999.9 km Track Angle Error R/L 180_ GS/TK Groundspeeed 999 km/h Track 359_ PP UTM UTM Zone Note 2 Area/Easting WV9999 Northing 9999 LAT/LONG Latitude N 84_00.0” S 80_00.0” Longitude E/W 180_00.0” DIST/BRG/TIME Time 99.9 Min. Distance to Go 999.9 km Bearing 359_ DEST/TGT UTM UTM Zone Note 2 Area/Easting WV9999 Note 3 Northing 9999 LAT/LONG Latitude N 84_00.0” S 80_00.0” Longitude E/W 180_00.0” SPH/VAR Spheroid Note 1 Variation Note 4 E/W 180_ NOTES: 1.  See table 3-3-3 for spheroid data codes and covered areas. 2.  Numeric: 01-60. Alpha: C-X, except I and O. 3.  Typical 100 km Designator: Column Designator: A-Z, except I and O. Row Designator: A–V, except I and O. 4.  Variation displayed is for destination indicated by DESP DISP thumbwheel. b.  MODE selector — TEST. After about 15 seconds, left display should display GO. Ignore the random display of alpha and numeric characters which occurs during the first 15 seconds. Also ignore test velocity and angle data displayed  after  the  display  has  frozen.  After  about  15 seconds, one of the following five displays will be ob- served in the first two character positions in the left dis- play. NOTE If  the  MAL  lamp  lights  during  any  mode  of operation except LAMP TEST, the computer- display  unit  MODE  switch  should  be  set  to OFF, and then to TEST, to verify the failure. If the  MAL  lamp  remains  on  at  TEST,  notify maintenance. If the TEST mode display is MN or NG, the MODE switch should be recycled through OFF to verify that the failure is not a momentary one. If the TEST mode display is MN, the data entry may be made in the UTM or LAT/LONG mode, but any navigation must be carried on with the system in the BACKUP mode. DISPLAY LEFT RIGHT REMARKS GO Display blanks System is operating satisfac- torily. GO P If right display is P, then pitch or roll data is missing or in er- ror. In this case, pitch and roll in the computer are both set to zero and navigation is de- graded. Problem may be in the vertical gyroscope or heli- copter wing. BU C, R, S, or H fol- lowed by a nu- meric code A failure has occurred and the system has automatically switched to a BACKUP mode of operation using last re- membered velocities for na- vigation. The operator can, as