Hi,
the surname Eberhardt is relatively common. By searching the online database that the Volksbundes Deutsche Kriegsgräberfürsorge e.V., the organization that are responsible for the German war graves, I found 689 persons registered with this surname.
If You are going to succeed in Your search You will have to get a bit more information about this relative of Yours (a given name and birth date or year would definitely narrow the number of results a lot).
There are bound to be several Eberhardt's with a Luftwaffe background lost at the eastern front, but if You are curious about what information the above mentioned database can give You, follow this link:
http://www.volksbund.de
Regards,
Andreas