What function(s) were the Russian ground effect planes meant to carry out:

Be invisible to radar and sonar, Transport military cargo, Transport troops, Fast sea patrol

The primary function of Russian ground effect planes, specifically designed ekranoplans like the Lun-class and the Caspian Sea Monster, was to transport military cargo and troops. These vehicles utilized the ground effect principle, also known as wing-in-ground effect (WIG), to achieve high-speed travel over water surfaces at low altitudes.

The ground effect planes were intended as a means of fast transportation for military purposes, allowing for the efficient deployment of troops and equipment over long distances. Due to their ability to fly at incredibly low altitudes and at high speeds, they were also considered for fast sea patrol and military reconnaissance operations.

While being relatively low to the surface, these ekranoplans might have enjoyed some level of reduced visibility to radar systems, potentially offering a stealth advantage. However, it is not accurate to state that these planes were specifically designed to be invisible to radar or sonar. Their primary functionality was centered around the transportation of military resources and personnel.

The Russian ground effect planes, also known as Ekranoplans, were primarily designed to transport military cargo and troops, not to be invisible to radar and sonar. These unique aircraft were optimized for low-altitude flights over water, utilizing the ground effect phenomenon to achieve high speeds and long ranges. Although they could conduct fast sea patrols due to their speed and maneuverability, their main function was to transport military personnel and cargo in a more efficient and rapid manner compared to conventional aircraft or surface vessels.

The Russian ground effect planes, also known as ekranoplans, were primarily designed to fulfill two functions:

1. Transport military cargo: Ekranoplans were intended to carry heavy military equipment and cargo over long distances at high speeds. They were designed to operate in a so-called ground effect, which refers to a phenomenon where a winged vehicle flies very close to the water or ground surface, taking advantage of the increased lift generated in this configuration. This allowed the ekranoplans to carry significant payloads, similar to aircraft, but at much higher speeds than traditional ships.

2. Fast sea patrol: The unique design of the ekranoplans allowed them to swiftly patrol large coastal areas or maritime territories. By flying close to the water surface, they could cover long distances quickly and effectively monitor the surrounding waters, making them suitable for reconnaissance and surveillance missions.

It's important to note that the primary focus of ekranoplans was not to be invisible to radar or sonar. Although their low altitude flight would naturally make them more challenging to detect by radar systems, they were not specifically designed for stealth capability like certain stealth aircraft. Similarly, their ability to avoid sonar detection would be limited, as sonar primarily detects underwater objects rather than aircraft.