There was one incident with the 1st Experimental Guided Missiles Group and a B-29. On July 29,1947 B-29 s/n 44-86307 had a takeoff accident Here is a short description ASN:
On July 29, 1947, nine crew were killed and two injured in a failed take-off attempt from Eglin Field, Florida at 08:13 hours, the bomber coming down approximately 300 yards North of the main base near Valparaiso, Florida and burning. Killed were:
Instructor pilot Capt. Gordon W. Barrett, of Pittsfield, Massachusetts, a West Point graduate who was awarded the DFC while flying B-29s in World War II
Trainee pilot 1st Lt. Huddie C. Bagley of Braufield, Texas
Co-pilot Capt. Robert M. Seldomridge of Lancaster, Pennsylvania
Navigator 1st Lt. Joseph A. Anderson, Shalimar, Florida
Navigator 1st Lt. Milton Rose, Fort Walton, Florida
Engineer Master Sgt. Michele Aulicino, Mary Esther, Florida
Scanner Staff Sgt. Hugh T. Mulholland of Philadelphia, Pennsylvania
Scanner Cpl. Ashley W. Odom, McBee, South Carolina
Scanner Pfc. Donald D. Crawford from Fort Worth, Texas.
Injured were:
Scanner S/Sgt. Jeremiah W. Conlon of Worthington, Kentucky, admitted to the Eglin hospital with abrasions of the face and head, and ankle injuries
Radio operator S/Sgt. Lloyd D. Farris of Pensacola, Florida, with minor injuries but admitted for observation.
The Superfortress apparently failed to gain much altitude before coming down, said Capt. Robert Gaughan, base public relations officer.
https://aviation-safety.net/wikibase/98581