(d)
Press W4 or E6 key for west or east present position longitude and observe that 000.00.0 followed by correct letter (W or E) appears in right-hand data display.
(e)
Press numbered keys in sequence for present position longitude and observe that correct longitude appears in right-hand data display.
NOTE: If incorrect data is displayed, press CLEAR key and
____
repeat steps (d) and (e).
(f)
Press INSERT key. Observe that INSERT key light extinguishes and that correct present position data within 0.2 minute is displayed in both left-hand and right-hand displays.
(g)
Place data selector to DSR TK/STS and observe that status 80 is displayed in right-hand display.
(h)
Place MSU mode selector switch to ALIGN and check that status 70 is displayed in right-hand display. Note and record time.
(4) Waypoint Coordinate Entry
(a)
On each control display unit place the data selector to WPT and WPT switches to 1.
(b)
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.
NOTE: If incorrect data is displayed, press CLEAR key,
____ observe that INSERT key light goes out, and repeat steps 1) and 2).
EFFECTIVITY AIRPLANES WITH LTN-72 INS
CONFIG 01 A Page 503 Aug 25/87
34-41-00
MODE ALIGNMENT TIME STATUS SELECTOR OPERATION REQUIRED NUMBER
STBY Warm-up Gyro Spin-up 1-3 min. 90
STBY Analog Fast Level 2 min. 80
NOTE 1: System will remain in Status 90 until the INU up-to-temperature signal is generated. This will also extend the time required to obtain the READY NAV light.
NOTE 2: Alignment will not progress beyond this point until present position is entered and ALIGN selected.
ALIGN Digital Fast Level 2 min. 70, 60
ALIGN Loop Stabilization 2 min. 50
ALIGN Fine Align 2 min. 40
ALIGN Fine Align (automatic gyro bias determined) 8 min. 10 reducing to 02
NAV Completed 17 min. 01
Alignment Sequence/INS Status Display
Figure 501
EFFECTIVITY
CONFIG 2AIRPLANES WITH LTN-72 INS
799 Page 504
34-41-00
Apr 25/86
T34621
3) Press INSERT key. Observe that INSERT key light extinguishes and that correct data (within 0.2 minute) is still displayed in left-hand data display.
4) Press W4 or E6 key for west or east waypoint longitude. Observe that INSERT key illuminates and that 000.00.0 followed by correct letter (W or E) appears in right-hand data display.
5) Press numbered keys in sequence for first waypoint longitude and observe that correct longitude appears in right-hand data display.
NOTE: If incorrect data is displayed, press CLEAR key,
____ observe that INSERT key light goes out, and repeat steps 4) and 5).
6) Press INSERT key. Observe that INSERT key light extinguishes and that correct data (within 0.2 minute) is still displayed in right-hand data display.
(c) Repeat steps (a) and (b) for additional waypoint insertions. Set WPT switch to position 2 up to 9 consecutively while entering each successive waypoint.
(5) Check INS Status (All INS)
(a) Place data selector to DSR TK/STS and observe that two-digit status number appears in right-hand display (Fig. 501). The number starts high (90) and decrements toward 01 as the alignment progresses. The READY NAV annunciator illuminates when the status reaches 02.
NOTE: If the status number changes from 02 to 10, the READY
____ NAV annunciator goes out and stays out until the status number again changes to 02.
(6) Check INS/HSI Interface
(a)
Position the following switches: 1) INS switch to normal position (Capt 1 - F/O 2) 2) VOR-ILS/INS switch to INS (panel P72)
(b)
Ensure that the CDU AUTO/MAN/RMT switch is in MAN.
(c)
Verify that the MSU mode selector switch is set to ALIGN.
(d)
Verify that the CDU FROM/TO display is 00.
(e)
Set the control display unit WPT switch to any position except
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