The USAAF had an operational helicopter squadron during WW2.
ack-ack
Yeah, saw the Wiki article and I'm having a hard time trying to source which USAAF squadron and with how many helicopters and what model. I do know the Sikorsky R-4 was using in 1944 on a operational S&R role (Dorr, Robert. History in Blue, Air Force Times, 22 March 2004. )...but that was a single chopper and I can't seem to source the squadron that used them on a operational level like a P-51D. I also have a bunch more R-4's used on 6 re-supply ships with two each (12 in total) and were used to ferry aircraft parts.(Williams, Dr. James W. A History Of Army Aviation: From Its Beginnings To The War On Terror. Bloomington, IN: Iuniverse, 2005) - Wki has that one too. And I'm sure Wiki has more examples of their use in ferrying small items around or doing the odd rescue, but nothing like a squadron of 50 R-4's with lots of examples of their operational due day to day. But I've asked for citation references on Wikipedia to verify the actual squadrons used and dates.
So, it's not a bad idea, just not a practical one.