Sid,
It's a little known fact that during the Cold War, the AAC Lynx were actually employed on Anti Stealth Blade Operations (ASBOs). Those Lynx blades were designed to be used as noise decoys, to draw enemy fire away from the RAF helicopters, coming along in the next valley, bringing in the troops. The AAC were never told this, in the interests of maintaining the morale of the crews.
Hence your very credible story about the Russian helicopter, which was able to sneak up behind. Noise / quiet are only relative, after all.
Similarly, the Gazelle was occasionally provided as cover for the Lynx. These aircraft were regarded as completely expendable, so were only given to lower ranks to fly and single manned. The Gazelles were known as Little 'Elicopters Sadly Beyond Operational Stuff, or LESBOS for short.
Fortunately for the AAC, it all went for a ball of chalk when the "BUBWAN" Chinooks arrived in theatre. (Big, Ugly Buggers, What A Noise).
P.S. I think that if the crossing of the IGB had ever occurred, there would have been more than a few FARTS coming up from the rear.
