The A-90 Orlyonok was designed to operate in ground effect (altitude significantly lower than its wingspan). If I understand correctly, when in ground effect, the L/D ratio is better due to induced drag being lower. Thus, I imagine the L/D ratio of the A-90 is high when cruising near at low altitude, but I failed to find any figure *. Moreover, according to Wikipedia, this aircraft have a ceiling of 3000m (not really in ground effect).
I'm interested in the performance differences between flying at ground effect altitude and at almost 10000ft AGL.
What were the L/D ratio of the A-90 Orlyonok at its different operating altitudes (when in ground effect, at its ceiling, and at any other altitude it would spend time flying at)?