Fine, what about the lack of radar signature - unable to be detected either from nearby ground-based installations, the helicopter's dedicated radar or the addi

Fine, what about the lack of radar signature - unable to be detected either from nearby ground-based installations, the helicopter's dedicated radar or the additional radar on the IR sensor cluster? I think that was the more interesting point. Also remember the helicopter was travelling at reasonably low speeds of 132 knots, or 152 mph yet if we're looking at the turbofan exhausts/afterburner we should expect object to reduce in size accordingly.