Hi Rammjaeger and Michael,
If he's a American, I have a possible candidate on the 9th July 1944 :
William B. Dale
First Lieutenant, U.S. Army Air Forces
Service # O-801255
344th Bomber Squadron, 98th Bomber Group, Heavy
Entered the Service from: California
Died: June 9, 1944
Missing in Action or Buried at Sea
Tablets of the Missing at Florence American Cemetery
Florence, Italy
Awards: Air Medal with 3 Oak Leaf Clusters, Purple Heart
He's the only American with the name Dale and officer who possibly could be your man.
You can check US WWII personnel (as well as WW I, Korea, Vietnam) that was KIA or MIA overhere :
http://www.abmc.gov/searchww.htm
Best from Johan