Flown by Gustavo Castaldo in the 1929 Challenge International de Tourisme. Photo from: Bibliothèque nationale de France - Gallica

The prototype of the Raab-Katzenstein RK 25. The third of three examples built, D-1701, also took part in the 1929 Challenge International de Tourisme and is seen on the far left wearing start number B3. B5 is the Akaflieg Darmstadt D 18, D-1561. The third aircraft is a BFW M 23, D-1711 / A9, flown by Alexander von Bismarck and wearing his famous family name. I-AANH / K3 is again in the background. Photo from: Bibliothèque nationale de France - Gallica

Belgian-designed plane powered by a Walter Vega engine. F-AJGT / F5 is a Potez 36. I-AANH / K3 is in the airship hangar. Photo from: Walter

'Lombardi and Cupini.' Francesco Lombardi piloted this aircraft in the 1929 Challenge International de Tourisme. He took the ninth place in the 5942-km rally around Europe and 13th place in the overall contest, including technical trials. 'Cupini' looks suspiciously like Gino Capannini; Lombardi and Capannini flew another AS.1, I-AAVE, from Vercelli to Tokyo in 1930. Photo from: Bibliothèque nationale de France - Gallica

Powered by a 80-hp Cirrus engine and flown by Franz Kirsch during the 1929 Challenge International de Tourisme. Photo from: Bibliothèque nationale de France - Gallica

A better view of the sole Arado L.I. The date is given as 5 August. The aircraft crashed that afternoon, killing its designer, Hermann Hofmann. In the background are two Breda Ba 15 aircraft, I-AAAO / M4 and I-AAAP / M5. Photo from: Bibliothèque nationale de France - Gallica

Technical trial for the 1929 Challenge International de Tourisme. Easy folding for parking in small hangars scored points. Photo from: Hagley Museum and Library

CANT landplane trainer. I-AAPO was the only example to take part in the 1929 Challenge International de Tourisme but pilot Mario Stoppani damaged the aircraft in Basel which was the first stop in the rally from Orly. Event code K7 is in the circle behind the rear cockpit. Photo from: Bibliothèque nationale de France - Gallica

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

The photo must have been taken during the Challenge International de Tourisme 1929 rally, with the 'German fuel depot' in the background. The Hungarian photo source says 1934 but the aircraft was apparently destroyed in 1933. Photo from: Fortepan