Alongside its first fifth generation stealth fighter, the Su-57, Russia's Air Force is also set to induct into service all new stealth munitions by the end of 2018. While the Su-57 is designed primarily for an air superiority role, it will also have a limited function as a strike fighter - for which an all new bomb, the Drel, was designed. While Russian fighters will be equipped with the advanced and newly designed 193km range K-77 air to air missile for air to air combat, the Drel will provide the fighters with sophisticated precision strike capabilities for an air to ground role.
The Drel was designed with properties which not only made it extremely difficult to intercept, but also significantly enhanced the survivability of aircraft launching the bombs - augmenting the Su-57's already formidable stealth capabilities. As a “fire and forget” bomb, the Drel does not require further guidance after launch such as illumination of the target or wire guidance by an aircraft. It can hit its target without the launching aircraft maintaining line of sight. This is a highly prized property for a guided weapon, ensuring that the aircraft which launches the bomb need''t loiter near the target to guide it and is thus both free to perform other tasks and less vulnerable to retaliation. With stealth fighters most vulnerable to detection when deploying munitions, the Su-57's ability to fire its payload and quickly depart is invaluable.
Another key advantage the Drel bomb is its ability to glide for long distances, up to 30km, which allows aircraft to drop it far from a designated target and thus maintain a safer distance from enemy forces. The Drel's use of high payload sub munitions mean it can strike with devastating effect and a large number of bombs and strike aircraft are not needed to eliminate most targets. A single cluster of sub munitions from the bomb are reportedly sufficient to destroy an entire missile battery or a tank column.
To complement the stealth capabilities of the Su-57, the Drel was designed with an extremely small stealth profile. The bomb is virtually invisible to radar and was designed to circumvent any radio electronic countermeasures. Deployment of such munitions from heavy stealth fighters makes for a truly lethal combination, and is particularly dangerous for adversaries which lack advanced counter stealth capabilities.
While the Drel will enter service alongside the Su-57, it is set to be deployed by a number of other Russian combat aircraft including bombers and attack aircraft. Deputy head of the Techmash Company Alexander Kochkin, who was heavily involved in the new bomb's development, stated: “The Drel can be used on all types of aircraft, from long range strategic bombers to ground attack planes." The Tu-22, Su-34 and Su-25 are likely candidates to receive the bombs, which could well be combat tested in Syria in the near future. Whether the K-77, the advanced air to air missile designed for the Su-57, will be operated by other combat aircraft such as the MiG-35, has been hinted at but ultimately remains to be seen.