XII only the B-57D could qualify as the required sampling aircraft. Meanwhile all agencies continued their efforts in the work of insuring that B-57D aircraft were approved and furnished with suitable modifications and sampling equipment. Dr. Plank wrote Lieutenant Colonel Richard J, Hynes, Director of Operations for the 950th Test Group (Nuclear) on 2h January 1957, and he sent another to Dr. Graves on 25 January 1957, and Dr. Graves to K. F. Hertford, 5 March 1957, L6 Admiral Hanlon assured Dr, Felt that he fully agreed to the collusion between all agencies to insure getting the B-57D, "I've instructed my staff to assist in this procurement in any way that the operational requirements of HARDTACK will support," he wrote, 4? - | Slightly more than four years after lending his first written support to the B-57 procurement campaign, Dr. Graves repeated the requirements to Brigadier General Canterbury. ( He further enlarged the requirements to include ten B-l;7B and four B-57B aircraft. He also sent notice of his intentions to use his influence with the Division of Military Applications to obtain that agency's assistance in getting the planes, Once fairly sure that their joint needs would be met on time by delivery of the B-57D, that confidence was jarred solidly as shown by a note of 26 February1957. Colonel Carney exhibited extreme concern resulting from the receipt of information that the B-57D would not be available prior to 1960, or not in time for use during HARDTACK.Y? A "pi pgyback" sampling installation on a B-57D owned by Strategic Air Command 25k SWEH ~2 -003)) 1° AF Wid HO y “2 Lay