AN / ALE-55

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The towed part of the ALE-55

The AN / ALE-55 ( JETDS designation) or “Fiber-Optic Towed Decoy” (FOTD) is a towed system for electronic countermeasures to protect fighter aircraft . It is produced by the British group BAE Systems .

description

The ALE-55 is based on the tow bait concept of the AN / ALE-50 system and is intended to protect the carrier platform from radar- guided guided missiles . As with the ALE-50, it can be used as a radar bait on the one hand, but also as an active jammer on the other. This results in a particular advantage compared to modern guided missiles, which can use the " home-on-jam " (HOJ) technology to capture and combat the source of interference as a target, since these now lock onto the towed system and no longer threaten the carrier aircraft.

The system itself consists of several towed radar baits, a launch device and a control system. The bait leaves the launcher on command and is pulled behind the machine by means of a cable a few dozen meters away. The system remains operational even during tough maneuvers and can withstand the hot exhaust gases of an afterburner engine . If the bait is hit and destroyed, the cable is hauled in and another bait is exposed. However, if it survives the threat intact, it can also be caught up and used again later. In contrast to the ALE-50, the ALE-55 is connected to the on-board electronics by means of a fiber optic cable , so that the drag bait can fall back on its computing power and thus represents a fully-fledged modern jammer. In general, the towed part of the system is only its antenna, since the jamming or bait signal is already completely "produced" on board the carrier aircraft and is then only sent out by the towed part. In order to achieve particularly high radiation output, two traveling wave tubes are used in parallel. The system is also integrated into the AN / ALQ-214 -EloGM complex. This also makes it possible to cover a much broader frequency spectrum, since the jammers on board the carrier platform and in the towed part can work independently in different frequency ranges.

The system has been operational since 2006 and the US Navy has procured some models for testing with the F / A-18E / F Super Hornet .

functionality

The combat process of the system is divided into three phases: As soon as the on-board radar warning system of the carrier platform detects an enemy guided weapon, the interference system on board the aircraft tries to prevent detection during the search phase with a high radiation power. If this fails, the jamming system of the ALE-55 is activated, which now tries to cancel the targeting of the enemy missile by means of the dragged jammer. Should this also fail, the system deactivates the jammer and activates the bait mode, which transforms the dragged jammer into a radar bait, which produces a considerably larger radar cross-section than the carrier platform, making it a more attractive target for the guided weapon. At the same time, Chaff is ejected by a decoy launcher on board the carrier aircraft in order to further confuse the approaching missile.

Platforms

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