The Boeing B-17H (re designated SB-17G in 1948) was a rescue conversion of a B-17G. The major addition to the aircraft was the capability to carry an A-1 lifeboat under the forward fuselage. The lifeboat was designed for airborne drops. Once a downed airman was spotted the rescue aircraft released the A-1 lifeboat which descended to the water by parachute. After the end of World War II, the defensive armament of the B-17H was gradually removed. The chin turret was replaced by an airborne search radar (ASR) and by the late 1940s the aircraft was flown unarmed. During the Korean Conflict, some of the defensive armament was restored. The tail and waist gunner positions were used along with cheek gun positions and top turrets in some cases. The SB-17G remained in service until 1956. In 1945, plans were made for the conversion of approximately 130 USAAF B-17Gs into search and rescue aircraft. They were to be modified to carry a lifeboat under the fuselage, and were to be re-designated the B-17H, "Flying Dutchman".  They provided air-sea rescue survices for the far-reaching world-wide operations of the USAF. At least two SB-17Gs survive in the USA today.

44-83575 is in storage awaiting restoration. 44-83722 was later deployed on the ground during a nuclear test and was heavily damaged, but its bits and pieces are currently in storage awaiting incorporation into other restored Fortresses. The droppable lifeboat was a self-righting, self-bailing type of boat that was equipped with full emergency provisions. It was carried underneath the belly of the aircraft and was dropped at sea by means of three parachutes. The boat extended from just aft of the chin turret fairing to the ball turret and was contoured to mold smoothly into the fuselage of the belly. Some of the earlier B-17H conversions were intended for operations in combat areas and retained their defensive armament. Others deleted the defensive armament entirely and replaced the chin turret with a search radar. The aircraft did not become operational until the war was nearly over. Nevertheless, the B-17H was instrumental in saving the lives of several B-29 crews during the last stages of the bomber offensive against Japan. Following the creation of the US Air Force, the aircraft designation scheme was revised in 1948. At that time, the B-17Hs were redesignated SB-17G, the S prefix indicating the primary search-and- rescue mission..

 Source:   US Air Force Museum