The good news is that they are available, bad news is that I can't remember who makes them since it's not really my thing. Keep looking on the net though I'm sure you will find them.
Try Historex, and remember that 75mm (or maybe it was 90mm - someone on here is bound to remember which) is pretty close to 1/24. Here's a link to a couple of ebay auctions, the company that makes these figures is Imperial Gallery, they do have a website. Not aircrew I know, but they might make others in 1/24.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=16511&item=5966746563&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=16511&item=5966746814&rd=1