- of the Soviet Ekranoplan (Caspian Sea Monster)
The "KM" or Caspian Sea Monster and the "Lun" are not the same. The original KM was even bigger than the Lun, but was destroyed in a crash. The Lun ("Harrier" in Russian) was the successor and was actually operational in the Soviet/Russian navy.
There was also a smaller, turboprop powered version which could climb out of ground effect to about 10,000ft. I would have thought, as somebody else pointed out, that such versatility would indeed be very useful as an MPA. I presume that there must be some intrinsic disadvantage, otherwise I expect the US would have looked at the technology too.