A number of modified RB-57As were used by the 7499th Support Group at Wiesbaden AB, West Germany in Operation "Heart Throb" reconnaissance missions over Europe. Ten aircraft were pulled off Martin's production line and modifications were performed in August 1955 by the Wright Air Development Center and by Martin. All equipment not absolutely essential for the daytime photography role was eliminated. The bomb bay door was removed and the area was skinned over. The seat for the system operator/navigator was removed, and an optical viewfinder was installed in the nose so that the pilot could perform all the reconnaissance duties without the assistance of the navigator. The clear plexiglass nose cone was replaced by an opaque fiberglass cone, but with a small optical glass window cut for the viewfinder. The plane's J65-BW-5s were replaced by higher-thrust J65-W-7s. The aircraft was referred to as RB-57A-1. The weight reduction program shaved 5665 pounds off the weight of the RB-57A, and the ceiling was increased by 5000 feet.