Polish media said that although Russia's Project 636 Varshavyanka (Kilo) submarine is nicknamed "black hole" because of its reputation for smooth operation, it is easy to "disappear" in the ocean, but there is still a weakness large enough that NATO can rely on it to detect them.
Polish media do not appreciate Russian military equipment. For example, the Defense Portal has a "tip" analysis for NATO about Russian diesel-electric attack submarines of Project 636.3 Varshavyanka.The Polish newspaper wrote that the Varshavyanka submarines, despite their low noise levels, have a "significant disadvantage" - that they cannot stay underwater for more than two days due to the lack of air-independent propulsion (AIP engine).
This is the "Achilles heel" of Russian diesel-electric submarines , despite the fact that the Kilos have extremely low operating noise levels that make them nicknamed "black holes".According to Polish experts, if it is known the approximate area of operation of the Russian submarine, as well as what type of submarine is in question, it is highly likely that it will be detected, because in 48 hours, the ship will finally be discovered because will have to emerge.
It is noteworthy that Warsaw also has a country with experience in operating Kilo-class submarines, when in the navy's payroll there is still one of Project 877 - the previous generation of Project 636 but between two submarine classes the above have many similarities.Poland's knowledge of Soviet/Russian-made diesel-electric attack submarines will certainly be of great help to NATO and this is a factor that Moscow cannot ignore.However, many Russian military experts believe that between the Project 877 submarines built during the Cold War and the advanced Project 636.3 today, there are actually too many differences and cannot be equated.
The fact has been proved by the fact that the whole NATO fleet along with anti-submarine patrol aircraft have repeatedly been powerless to find the Varshavyankas of the Russian Navy in a relatively narrow area.
