223 kts in a S-76C, chased home by an incoming Typhoon.
Mind you, the groundspeed outbound was only about 80kts. We "civvies" were asked by an embarrassed RAF Sqn Cdr if we could pick up some "observers" from a very small rocky island in the S. China Sea asap. They had previously placed the men out there and the typhoon changed course towards the island - meanwhile their only remaining Wessex had just gone u/s.....oops!
On arrival at the island I couldn't get the aircraft on the ground for a while due to extremely strong updraughting - our S-76 was hovering at about 5 feet with the collective fully down and the Nr kept going to the top limit in the very strong turbulence over the only possible landing place, on an into wind rock slab. As soon as the aircraft wheels touched, three very grateful soldiers did the quickest embarkation ever and we were up and away!