4-1-17. Countermeasures Dispenser System, AN/ ALE 47.

Figure 4-1-6. Flare Dispenser System (Sheet 1 of 2)

TM-1-1520-240-10 Army CH-47D Heilcopter (EIC:RCD) Manual
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TM 1-1520-240-10 4-1-10 5. If the ECM set is inoperative, proceed as follows: NOTE The crewmember observing a missile launch is responsible for firing the flares. a. Missile threat — Actuate the dispensing switch on the cyclic grip to fire flares or chaff or press one of the four firing switches in the cabin to fire flares. Fire a total of three flares or hold button down and timer will automatically space firing interval. NOTE The flare dispensers will fire one flare each time a button is pressed following the 2.5 sec- ond time delay or at 2.5 second intervals if the flare dispense button is held down. If the flare fails to ignite, a second flare will automatically fire within 75 milliseconds. If burning is still not detected, a third flare will be fired. If all three flares fail to ignite, automatic operation will stop until one of the fire switches is again pressed. b. Announce over interphone that a mis- sile launch was detected and flares have been fired. c. If more than one missile launch is ob- served, continue firing flares at 3-sec- ond intervals until the helicopter is clear of the threat. 4-1-15. Before Landing Check. 1. ARM-SAFE switch — Set to SAFE. 2. Indicator lights — Check that READY-TO- FIRE and ARM lights are out. 4-1-16. After Landing Check. 1. Check that the LDG GR SW Status light goes out. 2. Install the ground safety pin in the dispenser electric module. 3. Remove and stow the crew firing switches. 4-1-17. Countermeasures Dispenser System, AN/ ALE 47. (fig. 4-1-6) The AN/ALE-47 Countermeasures Dispenser System (CMDS) provides the aircraft with protection from air-to- air and surface-to-air heat seeking missiles. Modes of operation are manual (five stored programs), semi-auto- matic (operator/sensor activated), and automatic (opera- tor/sensor activated). The CMDS is integrated with the AN/ALQ-156 Missile Detection System to automatically dispense expendables when a threat is detected by the AN/ALQ-156 when in the AUTO or SEMI AUTO mode of operation. The CMDS may be pre-programmed to re- spond threat environments. The CMDS is comprised of the following components: a Digital Control Display Unit, (DCDU), a programmer, a junction box, two sequencers, and four dispenser as- semblies, each containing a payload module (maga- zine). The system also contains a safety switch and a Mission Load Verifier (MLV) interface port. Power required to operate the CMDS is 28 Vdc, 2 amps max in STANDBY and 7 amps for 20 milliseconds during each squib ignition, is taken from the No. 1 DC Bus. The three circuit breakers for the CMDS are found on the EAPS 1 PDP labeled DC ALE47. Power for the DCDU is taken through a 5 amp CB labeled DCDU. Power re- quired to jettison expendables is taken through two 10 amp CBs labeled PWR NO. 1 SEQ and NO. 2 SEQ.

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