AIRPLANES WITH DELCO INS CONFIG 1 03 A Page 38 Apr 25/8734-41-00
On AT 701-750, the portion of the network involving the INS consists of a captain's VOR-ILS/INS switch and transfer relay, a first officer's VOR-ILS/INS switch and transfer relay, a captain's INS transfer switch and relay, a first officer's INS transfer switch and relay, a captain's ATTITUDE switch and attitude/compass stabilization transfer relay, a first officer's attitude/compass stabilization transfer relay, and an instrument switching accessory box. The attitude switching is arranged so that the captain can select system No. 1 and the first officer system No. 2, or either pilot can select system No. 3.
(1)
The captain's VOR-ILS/INS switch controls the captain's VOR-ILS/INS transfer relay which allows the captain's HSI to display heading information from either the VOR/ILS and magnetic heading reference systems or the INS. The first officer's VOR-ILS/INS switch and transfer relay function in a similar manner for the first officer's HSI.
(2)
On ATLAS ALL EXCEPT AT 701-750, the INS transfer switch on the captain's instrument panel controls the captain's and first officer's INS transfer relays. Both relays are paralleled to function as a single unit. A switch position annunciator adjacent to the switch illuminates to show which INS systems are supplying heading information to the captain's and first officer's HSI's. The captain's instrument normally operates from INS 1 while the first officer's is operating from INS 2. Heading information from INS 3 is switched between the captain's and first officer's HSI's. On AT 701-750, the captain's and first officer's INS transfer switches are cross-connected to control the corresponding INS transfer relays. This allows each HSI to display information from either INS 1, INS 2, or INS 3.
(3)
On ATLAS ALL EXCEPT AT 701-750, the attitude/compass stabilization transfer switch on the captain's instrument panel controls two attitude/compass stabilization transfer relays. A switch position annunciator adjacent to the switch illuminates to show which INS systems are supplying attitude information to the captain's and first officer's ADI's. The captain's instrument normally operates from INS 1 while the first officer's is operating from INS 2. Attitude information from INS 3 is transferred between the captain's and first officer's ADI's. On AT 701-750, the captain's ATTITUDE transfer switch controls two attitude/compass stabilization transfer relays. The relays switch the captain's ADI and compass coupler No. 1 to receive attitude and platform heading information from either INS 1 (NORM position) or INS 3 (CAPT 3 position). The first officer's ADI and compass coupler No. 2 are similarly switched to receive information from INS 2 (NORM position) or INS 3 (F/O 3 position).
(4)
The instrument switching accessory box contains arc suppression diodes which are connected across the relay coils.
11. INS Cooling System (Fig. 14)
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EFFECTIVITY
AIRPLANES WITH DELCO INS CONFIG 1 02 A Page 39 Apr 25/8734-41-00
A. It is extremely important that inertial navigation units have an adequate cooling air supply since overheating will result in failure of the navigation units.
B. To ensure that the INS system will always have a supply of cooling air, an INS cooling air fan is installed in the cooling air exhaust plenum beneath each navigation unit. These fans operate independently from the main equipment blowers and provide the INS with a cooling air supply even if the main equipment cooling blowers are not operating.
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本文链接地址：747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航2(95)
