'Hunting for uranium, copper, lead and other metals is made easier and quicker with a new electromagnetic detector developed by Newmont Mining Corp. and engineered by Philadelphia's Aero Service Corp. The detector consists of two coils mounted on fore and aft booms on a Sikorsky helicopter. The front coil transmits a tuned electrical signal as it flies over the survey area. The metals cause disturbances in the signal, which are picked up by the rear coil. The aircraft covers more terrain in a day than foot-slogging ground crews do in months.' Photo from: Temple University Libraries

The Budd Company from Philadelphia was a leader in welded steel and its application in trains and cars. As a precaution against aluminum shortages, the US military awarded them contracts for a steel transport aircraft during World War II. The Conestoga was of modern configuration but unsurprisingly it was heavy and sluggish. Seventeen RB-1s were still completed for the US Navy and some of these saw use with civil operators. Photo by: Rudy Arnold / Smithsonian Institution

'Bulletin delivery airplane' - more likely an executive aircraft. The Philadelphia Bulletin was at one time the largest evening newspaper in the United States. Meanwhile operating in Alaska, N80194 went off the runway and crashed at Kodiak on 16 March 1967. Photo by: Dominic Pasquarella / Temple University Libraries

The second B-47 prototype, first flown on 21 July 1948. The photo is assumed to have been taken early on because of the yellow 'US Army Air Forces' bowser. Airframe survives, moved to the Flight Test Center Museum at Edwards AFB in 2016. Photo by: Rudy Arnold / Smithsonian Institution

The first factory-owned Freighter was quickly sent on a tour through North America - Bristol must have thought this concept might catch on in these rich lands. We're told the car is an Austin - with left-hand steering. Photo by: Rudy Arnold / Smithsonian Institution

Kenneth Ronan and Andrew Edward Kunzl from Marshall, Michigan designed the P-1 Explorer survey aircraft for aerial photographer Talbert Abrams. The sole example first flew in November 1937. Titles read 'Abrams Aerial Survey Corp. - Detroit-Lansing-Washington-San Juan P.R.' and 'Survey Ship No 14'. Aircraft survives in NASM storage, or at least the fuselage. Photo by: Rudy Arnold / Smithsonian Institution

Belgium ordered 40 Brewster B-339Bs in In December 1939. Flying here with the temporary reg NX56B, this was the only one to reach Europe. Captured in its crate in Bordeaux, it was presumably tested by the Germans as its remains were noted in Darmstadt in 1945. Photo by: Rudy Arnold / Smithsonian Institution

Yes, a 1941 colour photo. Ex NC18580, the 1937 D17 was bought from the Prest-o-Lite Battery Company by Bolivian pilot Capt Rafael Suarez Rivas Morales. His 'goodwill flight' to Bolivia from New York - Floyd Bennett Field ended in a crash in Washington DC. Capt Alberto Taborga escaped with burns but Rivas was killed. His body was flown to La Paz by a USAAC B-17B. Photo by: Rudy Arnold / Smithsonian Institution

MW169 was given to General de Gaulle by Winston Churchill in the summer of 1945. He may not have used it much himself since he also received a C-54, 44-9148, from President Truman. The aircraft wears regular French roundels on the wings and the Free French Cross of Lorraine on the fuselage; the latter was removed at some point. MW169 transferred to the French navy in 1954. The C-45F Expeditor on the right, 44-86905, was remanufactured with a new serial in 1952. Photo by: Rudy Arnold / Smithsonian Institution

C-87s were converted from B-24Ds at the factory and suffered from unreliable systems. Operated by Consolidated subsidiary Consairways, 41-11706 crashed into a mountain on Nggela Sule (Florida Island) on approach to Guadalcanal en route for Brisbane on 28 July 1944. The six crew and 21 high-ranking passengers were all killed, including an envoy carrying top secret documents for General MacArthur. Photo from: Hagley Museum and Library

This was the first Fw 190 to fall into Allied hands. Disorientated following air combat, Oberleutnant Armin Faber, a mostly deskbound staff officer of III/JG 2, mistook the Bristol Channel for the English Channel and landed at RAF Pembrey, Wales on 23 June 1942. Photo from: Imperial War Museums

The first Super Connie transport for the USAF. The first C-121C deliveries were to the Atlantic Division of MATS, in particular, the 1608th Air Transport Wing at Charleston AFB, which also had C-124 Globemaster IIs. Photo from: Hagley Museum and Library

Boeing's B-29 plant in Wichita was reopened to build B-47s. Nineteen are visible here. 51-2317 was damaged beyond repair in an aborted take-off at Homestead, Florida in 1957. 51-2220, 51-2284, 51-2294, 51-2312 and 51-2313 can also be identified. Photo from: Hagley Museum and Library

Also used for a fast trans-USA flight - see other photo - NR13770 made the fastest Atlantic crossing to date on 2 September 1936 between New York and Llandeilo, Wales. Pilot Dick Merrill and entertainer Harry Richman stuffed the plane with 41,000 ping pong balls, hoping to keep afloat in an emergency. For the return flight, oddly, no runway in Britain was long enough and Ainsdale Beach near Southport was used. The return flight nearly put the ping pong balls to the test, apparently due to Richman dumping fuel, but they made it to Newfoundland. Merill made another transatlantic return flight in L-10 Electra NR16059, in May 1937, again using Ainsdale Beach. Photo from: Hagley Museum and Library

In one of the airship hangars that stood at Orly, a German entry is weighed for the first edition of the Challenge International de Tourisme. It is the sole example of the Arado L.I, designed for the event by Hermann Hofmann. On 5 August the plane crashed as the wing failed during aerobatics that were not part of the Challenge. The pilot lost his life - Hofmann, who knew that his aircraft was not stressed for aerobatics! Photo from: Hagley Museum and Library

Single-seat helicopter powered by pulse-jet engines on the rotor tips, developed for USAF and US Army. It was designed to be air-droppable for rescue and observation purposes, but not proceeded with although the five prototypes proved to be rugged vehicles. The maker was bought by Fairchild in 1954. Photo from: Wright State University

Part of the same original as photo 398840 which shows a Messerschmitt Bf 109 with a swastika applied over an RAF fin flash. The P-40 was destined for the RAF as a Kittyhawk IA, ET350, but retained by USAAF instead. Photo by: Rudy Arnold / Smithsonian Institution

Oberfeldwebel Karl Hier of I/JG 76 had to land his Bf 109E at Wœrth, Alsace on 22 November 1939. It was test-flown by the French at Orléans - Bricy, then handed over to the RAF on 2 May 1940. In 1942 it was shipped to the USA for testing at Wright Field. Note the faux swastika painted on by the Americans - they liked to dress up captured aircraft and amazingly, even in this stage of the war it was apparently not a safety concern. We found information that the photo was taken at LGA during the filming of a propaganda reel. P-40E 41-25026 is seen on the right and a P-39 Airacobra, probably 41-7249, on the left. Photo by: Rudy Arnold / Smithsonian Institution

About to be hoisted onto a barge 'for shipment, by Erickson and Remmert, to Czechoslovakia, at pier near Floyd Benett Field'- probably near the Coast Guard seaplane ramp. The Bata company's first L-10A Electra, also registered OK-CTA (c/n 1068) was damaged in Chicago on 4 April 1937. To complete his trip, shoe king Jan Bata immediately bought OK-CTB (c/n 1091). It has been assumed that OK-CTA (c/n 1068) was repaired, but it is clear now that Bata received another airframe (c/n 1114). Photo by: Rudy Arnold / Smithsonian Institution

Following the racing success of the DGA-6, the DGA-7 prototype first flew in 1936 and the Howard Aircraft Company was formed to produce the DGA-8 series for the executive market. Note overpainted NC reg and North Beach Airport sign. This small airfield was soon expanded to become La Guardia. LGA soon proved insufficient, prompting the construction of Idlewild (JFK). Photo by: Rudy Arnold / Smithsonian Institution