The United States has developed and installed a version of the ALE-50 towed decoy system for use in F-35 stealth aircraft. The ALE-50 system is normally carried on one of the wing hardpoints and is a long circular canister that deploys the decoy that remains attached to the aircraft via a long cable. The ALE-50 can deceive surface-to-air and air-to-air missiles using a variety of electronic signals that can be controlled by the tethering aircraft's electronic warfare defense system.
In use since the 1990s, ALE-50 first proved its worth over Kosovo in 1999. The F-35 was originally designed without it, but a British defense manufacturer developed the ALE-70 just for the F-35 and this version can be carried internally in a compartment separate from the internal bomb bay. The U.S. Air Force has ordered ALE-70 and at least one foreign F-35 user (Australia) has ordered it. While the F-35 is indeed quite stealthy it is not invisible. F-35 engines put out a lot of heat that can be detected, while many ground-based air defense systems use passive (no radar signals) sensors using visual or thermal sensors to spot an F-35. While the F-35 also uses a lot of passive sensors, once spotted and targeted by missiles the ALE-70 can be a lifesaver.
Each ALE-50s cost about $22,000 and are stored and deployed from a sealed canister with a ten-year shelf life. They are built into the larger ALQ-184(V)9 ECM (Electronic Countermeasures pod carried by aircraft that do not have extensive internal ECM systems. ALE-70 is more expensive because of its special installation needs. ALE-50 continues to be useful and pilots refer to it as their “little buddy”. A more advanced version, ALE-55, is being developed. The ALE-55 is able to detect radar-guided anti-aircraft missiles, analyze the radar signal and emit the most effective signal to deceive the incoming missile and protect the tethered aircraft.