PHILADELPHIA --The B-24 Liberator depicted on one of the new U.S. Postal Service stamps is the Black Cat, chronicled in "Wings of Morning: The Story of the Last American Bomber Shot Down Over Germany in World War II" by Thomas Childers, a history professor at the University of Pennsylvania.

Childers, the nephew of a crewman killed in the crash, wrote the book based on his discovery of hundreds of his uncle's wartime letters.

He spoke at a first-day-of-issue ceremony to dedicate the "American Advances in Aviation" commemorative stamp pane July 29.  

"The issuance of this stamp is a fitting memorial for all the brave young airmen who flew the B-24 in the Second World War," Childers said, "but especially for the men of the Black Cat who died 60 years ago.  I know I speak for the families of those men when I say we are grateful -- and humbled -- to see their memory honored in this way."

Shortly after his grandmother died, Childers visited her home and discovered more than 200 of his uncle's wartime letters among her possessions.  Included was correspondence from crewmember relatives questioning the fate of their loved ones.  B-24 eyewitness accounts reported parachutes opening as the Black Cat fell from the sky, yet the families received killed-in-action and missing-in-action telegrams in the midst of VE Day celebrations.  Childers spent four years researching the day-to-day training and combat experiences of the crew from nearly 600 wartime correspondences.

The American Advances in Aviation stamp pane depicts innovations and technological contributions to military, commercial, and general aviation during the 1930s, '40s and '50s.  Photo: http://www.newscom.com/cgi-bin/prnh/20041105/DCF007-a )