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 redesignated B-17H.
My sources disagree on the number of search-and-rescue Fortress conversions that were actually carried out. Some say that only twelve such conversions were actually carried out, all of the planes being redesignated B-17H upon completion, with five of the B-17Hs being later redesignated TB-17H. The serial numbers of these B-17Hs are given at the end of this article. Other sources claim that all 130 of these conversions were eventually carried out, but that only the 12 aircraft indicated above were redesignated B-17H, with the remainder retaining their original B-17G designations. Still other sources maintain that all 130 of these planes became B-17H. Ah, the joys of research!
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.
Some of these SB-17Gs were still in service at the time of the Korean War, and those planes operating in Korean waters were refitted with cheek, waist, and tail guns for defensive purposes. They were administratively assigned to the world-wide Air Rescue Service, which was a part of MATS. They provided air-sea rescue survices for the far-reaching world-wide operations of the USAF.
All SB-17G conversions were retired by the mid-1950s, some being assigned to provide range control service at missile test sites. 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.
B-17G air-sea rescue conversions redesignated as B-17H:
44-83573 (or 5?), 44-83700, 44-83705, 44-83710, 44-83714, 44-83718, 44-83719, 44-83722, 44-83791, 44-83793, 44-83794, 44-83799.
Here some other numbers from Marshall Cram:
43-39457, 44-83575, 44-83802, 43-37652, 44-83511, 43-39266, 43-39502, 44-83713, 44-83474, 43-38882, 44-83707, 42-97825, 44-83700, 44-83539.
The question mark is there because a much-reproduced post-1947 photo of a lifeboat-carrying Fortress shows the plane with the number 44-83575 painted on it. This may mean that there is a typo in the first entry in the list of serials given above. But it could also mean that there were more than the above listed number of lifeboat-carrying Fortresses conversions that were actually carried out.
B-17H conversions to TB-17H:
44-83700, 44-83714, 44-83718, 44-83791, 44-83793.