left-hand data display is all Zeros and an N.
5) On airplanes with INS program 72-28-0, program number 72 28 is displayed in the right-hand data display. For the complete program number 0 is displayed in the right-hand display when the HOLD pushbutton is pressed.
6) On airplanes with INS program 72-50-01, program number 72-50-01 is displayed as 72 in left display and 50 01 in right display.
7) On airplanes with INS program 72-50-02, program number 72-50-02 is displayed as 72 in left display and 50 02 in right display.
8) On airplanes with INS program 72-50-03, program number 72-50-03 is displayed as 72 in left display and 50 03 in right display.
9) On airplanes with INS program 72-50-04, program number 72-50-04 is displayed as 72 in left display and 50 04 in right display.
(2) Display Test
(a) The display test enables the pilot to verify that the CDU numerical displays, FROM/TO displays, and annunciators are operating correctly. Perform the display test as follows:
EFFECTIVITY AIRPLANES WITH LTN-72 INS
CONFIG 01 A Page 53 Aug 25/87
34-41-00
1) Set display selector switch to TEST and the WPT switch to any position except 0.
2) Check that the left and right numerical displays are degree signs, decimal points, arc-minute signs, NS (superimposed), EW (superimposed), and all eights except left digit of right numerical display is R. FROM/TO display is all eights, and ALERT, BATT, and WARN annunciators and TK CHG, INSERT and HOLD indicators are on.
(3) Present Position Entry
(a) The aircraft's present position must be entered into the INS digital computer before the INS can be aligned. If an error is made during the procedures, press the CLEAR pushbutton and repeat the procedures. Enter present position as follows:
CAUTION: IF PRESENT POSITION LATITUDE IS INSERTED INCORRECTLY
_______ THE INS WILL DETERMINE, DURING CALCULATIONS PERFORMED LATER IN THE ALIGNMENT SEQUENCE, THAT THE ERROR EXISTS, FLASH THE WARN ANNUNCIATOR, AND STOP THE SELF-ALIGNMENT SEQUENCE.
1) Verify that mode selector switch is set to STBY. 2) Set display selector switch to POS. 3) To start latitude entry procedures, press N or S
pushbutton on data keyboard.
4) Verify that left numerical display blanks, N or S on left numerical display comes on, and INSERT pushbutton comes on.
5) Starting with most significant digit, enter latitude to nearest tenth of a minute by pressing corresponding pushbuttons on data keyboard. As each pushbutton is pressed, verify that corresponding digit is displayed on left numerical display as least significant digit, and that each preceding digit moves one place to left.
6) Verify that latitude display is correct, then press INSERT pushbutton. If the display is not correct, press CLEAR pushbutton and re-enter latitude.
7) To start longitude entry procedures, press W or E pushbutton on data keyboard.
8) Verify that right numerical displays blank, W or E on right numerical display comes on, and INSERT pushbutton is still on.
9) Enter longitude in same manner as latitude.
10) Verify that longitude display is correct, then press INSERT pushbutton. Verify that INSERT pushbutton goes off. If the longitude is not correct, press CLEAR pushbutton and re-enter longitude.
NOTE: A latitude or longitude entry of all zeros is not
____
valid.
EFFECTIVITY AIRPLANES WITH LTN-72 INS
CONFIG 01 A Page 54 Aug 25/87
34-41-00
11) Set mode selector switch to ALIGN.
(4) Waypoint Data Entry
(a) Waypoint latitude and longitude are entered in a similar manner as present position except that the display selector switch is moved to the WPT (waypoint) position, and the waypoint thumbwheel should be set to the proper waypoint number (1 thru 9).
NOTE: When entering waypoints, the INSERT pushbutton goes out
____ after entering the first coordinate.
Waypoint 0 is reserved for the computer to establish a track from the airplane present position, and cannot be used by the operator to enter waypoint coordinates.
(b)
Ensure that each MSU mode selector switch is set to ALIGN.
(c)
On each control display unit place the data selector to WPT and WPT switch to 1.
(d)
On any one control display unit perform the following.
1) Press N2 or S8 key for north or south first waypoint latitude. Observe that INSERT key illuminates and that 00.00.0 followed by correct letter (N or S) appears in left-hand data display.
2) Press numbered keys in sequence for first waypoint latitude and observe that correct latitude appears in left-hand data display.
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