Aero Vintage Books

Books and Information for the Aviation Enthusiast

The First U.S. Civil B-17: Sperry’s NX60475

The First U.S. Civil B-17: Sperry’s NX60475

For those who have an interest in such things, there are usually two B-17s that are given credit for being the first U.S. civil B-17. The first is Paul Mantz’s B-17F 42-3360, purchased by Mantz in February 1946 but, significantly, not actually civil registered (as N67974) until 1950. The other is B-17G 44-85728, purchased by TWA in June 1946 and civil registered as NX4600 (initially). But there is another much-overlooked B-17 that actually received a civil registration as early as September 1945. There is little information about this B-17, but I shall present here what has been dug up. It proves to be an interesting and surprising story.

As a bit of an aside, there were at least four Swedish-operated civil B-17s that predate the first U.S. civil registered B-17. And, it should be noted that Boeing’s Model 299 prototype of the B-17 was a civil registered aircraft from July 1935 until October 1935 (when it crashed). However, technically, this aircraft was never a military aircraft and was not a B-17.

Sperry Gyroscope gets an RFC B-17F

The Sperry Gyroscope Company, famous in B-17 lore for its upper and lower turrets installed on all production B-17Es, B-17Fs, and B-17Gs, obtained a well-used B-17F at some point in 1945. This was B-17F 41-24434, a combat veteran turned over by the AAF to the Reconstruction Finance Corp. in November 1944 for disposal. This is in itself a bit unusual as most war-weary B-17s that had returned to the U.S. from overseas theaters were still used as crew trainers.

B-17F 41-24434 used for A-12 Autopilot Testing

So, Sperry obtained the aircraft from the RFC but there is no information available about that transaction. Beginning in the summer of 1945, it was used as a test-bed for the development of its new A-12 autopilot. Installation of the autopilot, with associated servos, instruments, gyros, and electrical equipment, began on July 20, 1945, and the aircraft’s first test flight with the autopilot was made on October 3, 1945. Prior to that flight, the B-17F received the civil registration of NX60475 from the U.S. Civil Aeronautics Administration (CAA). The airplane was based at the Sperry flight department hangar at MacArthur Airport, near the town of Islip, on New York’s Long Island. It is not known how long the A-12 flight tests lasted, but Sperry Gyroscope published an internal report on the installation on December 28, 1945. That report is entitled “A-12 Installation to B-17F Serial No. 41-24434.” the A-12 autopilot program continued for many years after this initial test series. How much the B-17 was used for that is unknown.

Below is a photo from that Sperry report, and appears to show NX60475 on the Sperry ramp in the fall of 1945 during the test series. As can be seen, the airplane is unpainted and unmarked, save for the civil registration applied vertically on the rudder. Note the B-17 has an extra window added below the other nose windows and just aft of the nose glass, a detail that will be covered a bit later. Also, note the AAF B-24 in the background.

Sperry operated a number of aircraft from its base at MacArthur Airport through the years. The photo below shows the Sperry B-17, two DC-3s, and a a USAF B-29 and F-80, both most likely at the Sperry facility for installation or test work. It is probably the photo is dated from the late 1940s.

Below is an enlargement of the B-17F from the above photo. The airplane has a pretty distinctive paint scheme. It appears the civil registration remains painted vertically on the rudder.

One of the problems in documenting the civil use of B-17F 41-24434 is that the FAA aircraft file was destroyed in April 1962. Thus, no documented history is available and, instead, must be pieced together from other sources.

As an aside, the Sperry A-12 autopilot was fully developed and installed on many, if not most, civil airliners and a variety of civil aircraft in the 1950s and 1960s. It was designated as the USAF E-4 autopilot and similarly installed on a large number of USAF transport and other military aircraft.

Subsequent History of B-17F 41-24434 N60475

Available sources indicate that a some point, probably about 1950, Sperry sent the B-17F to aircraft broker Charles Babb Company, either by sale or consignment. It was subsequently sold to Bolivian operator Lloyd Aereo Boliviano, where received the civil registration of CB-79. Sometime later, probably in October 1954, it was re-registered as CP-579. A later operator was reportedly Frigorificos Grigotas. It was reported as damaged or destroyed at Unica, Bolivia, on December 29, 1958, with no casualties.

Early History of B-17F 41-24434

B-17F 41-24434 is unusual as a civil B-17 because it had significant combat use with the 12th Air Force in Northern Africa during the early years of World War II. 41-24434 was built by Boeing at Seattle and delivered on June 30, 1942. It was initially set to participate in Operation Bolero, the first mass movement to deploy the 8th Air Force to England. However, it was instead assigned to the 15th Photo Mapping Squadron (PMS) of the 3rd Photo Reconnaissance and Mapping Group (PRG) at Lowry Field, Colorado. It was back at Boeing in September 1942 for, apparently, modifications for photo reconnaissance. The group went overseas in October1942, initially based at RAF Membury as part of the infant Eighth Air Force. There is also a reference in a 306th Bomb Group document that suggests it was briefly assigned to that group.

In any event, the 15th PMS deployed to Algeria as part of Operation Torch in November 1942, and was subsequently assigned to the Twelfth Air Force. The balance of 41-24434‘s operational service appear to be from bases in Algeria and Tunisia, though its record card shows possible assignment to the 12th Air Force in Italy in 1944. It is known that it conducted photo mapping missions in Nigeria and along the Gold Coast area in western Africa in March 1943. Other than that, details of the missions it flew are not found, but photographic evidence shows it well worn and armed, so there was some obvious utilization.

In the photo above, it can be seen that 41-24434 carried the name and nose art of The Mudhen. Note the nose window modifications and the extra windows located on the lower side of the nose just aft of the nose glass, installed as part of the photo recon modifications. Notations on the slide mount of the photo indicates it was taken at RAF Mount Farm in the UK in 1943. It also documents that it is the aircraft of Col. Elliot Roosevelt, son of FDR, who was commander of the 3rd PRG from July 1942 until March 1943. Presumably, the aircraft is in the UK with Roosevelt for a conference or some other military business.

It is interesting to note that later B-17Fs modified for photo mapping and reconnaissance were re-designated as F-9s or F-9As. 41-24434, however, remained a B-17F through its military service. There are no specific details I have found about the specific modifications to it and other similarly modified B-17Fs used for photo mapping with the same units, known to include B-17F 41-24433 and B-17F 41-24440.

The photo below shows the whole aircraft, also notated as being take at RAF Mount Farm in the UK in 1943.

As per the AAF record card, 41-24434 returned to the U.S. in July 1944. It spent the late summer and fall of 1944 assigned to the Tinker (Oklahoma) Air Service Command, use unknown. Then, as noted above, it was turned over to the RFC on November 22, 1944. This last part is a bit puzzling as the RFC was not (officially) designated as the disposal agency for domestic surplus aircraft until April 1945. The record card shows the last AAF station for 41-24434 as station number 3124. That location is not divulged on my AAF station list on hand, but may have been in Maryland. The possibility exists that 41-24434 was set aside for Sperry and made available for purchase, but this is only speculation.

The Mysteries of B-17F 41-24434

Several mysteries surround the Sperry B-17. First, why would a tired, war-weary B-17 be purchased by Sperry for the A-12 autopilot tests? The probable answer is that it was all that was available at the time Sperry came looking. Second, what were the details of the acquisition of 41-24434 from the RFC? How much did Sperry pay for it, if anything? And finally, why are there virtually no located photos of a civil B-17 that operated from a civilian airport on Long Island for five years. It would seem those New York aviation photographers were not on the ball. Where was Bill Larkins when you needed him?

Finally, I’ll note a couple of useful sources for the information contained here. First, I was able to dig up and receive a copy of the Sperry Gyroscopic Co. report dated December 28, 1945, from the Hagley Library located at Greenville, Delaware. The Hagley Library contains a large part of the Sperry Co. archives. A very nice researcher pulled the report and copied it for me. Also, Steve Birdsall’s Pride of Seattle: The Story of the First 300 B-17Fs proved valuable in looking at the early history of this B-17. And, I won’t discount my own B-17 files on this airplane which are incorporated into the book Final Cut: The Postwar B-17 Flying Fortress and Survivors.