mid-wing). Only five were of all-metal construction, most were all-wooden. On contrary to a previous contest, there appeared also some special aircraft, better suited to meet the Challenge demands. First of all, they were German BFW M.23c and Klemm L 25E, being new variants of successful machines of 1929 – wooden low-wing monoplanes with closed canopy, belonging to lighter category, yet fitted with powerful Argus engines, having better chance in technical trials. All aircraft in the contest had fixed conventional landing gear and had no wing mechanization (slats or flaps) yet. Aircraft participating were BFW M.23c (10), BFW M.23b (1), Klemm L.25 (4), Klemm L.25E (3), Klemm L 26 (2), Klemm VL 25 (1), Junkers A50 (3), Arado L II (4), Albatros L 100 (1), Albatros L 101 (1), Darmstadt D-18 (1), de Havilland DH.60G Gipsy Moth (6), Avro Avian (1), Spartan Arrow (1), Monocoupe 110 (1), RWD-2 (3), RWD-4 (3), PZL.5 (2), PWS-50 (1), PWS-51 (1), PWS-52 (1), PWS-8 (1), Caudron C.193 (3), Caudron C.232 (1), Peyret-Mauboussin PM XI (1), Saint Hubert G1 (1), Breda Ba.15S (1), CASA C-1 (1). 20 aircraft were assigned to the Class II with net weight up to 322 kg (300 kg plus 15%), the remaining 40 to the Class I with net weight up to 460 kg (400 kg plus 15%). Class II aircraft were 11 German BFW M.23s and 5 Klemm L.25s and L.25E's (apart from two L.25 IVa), 3 Polish RWD-2s and one French PM XI. The classes had influence on awarding points for cruise speed and fuel consumption only. The aircraft had alphanumerical starting numbers, the German from a range: A2-A9, B3-B9, C1-C9, D1-D8, E1-E9, F1-F2, British: K1-K8, French: L1-L3, M1-M6, Polish: O1-O9, P1-P5, Swiss: S1-S2, Spanish: T1-T7 (numbers were painted in a circle, with inscription: Challenge International and 1930). Circuit over Europe The contest in 1930 was the only Challenge, in which a rally was the opening phase. It was a 7560 km circuit over Europe, with compulsory stops at: Berlin – Braunschweig – Frankfurt – Reims – Saint-Inglevert – Bristol – London – Saint-Inglevert – Paris – Poitiers – Pau – Zaragoza – Madrid – Seville – Zaragoza – Barcelona – Nimes – Lyon – Lausanne – Bern – Munich – Vienna – Prague – Breslau (Wrocław) – Poznań – Warsaw – Königsberg (Kaliningrad) – Danzig (Gdańsk) – Berlin. Distances ranged from 77.5 km (Lausanne – Bern) to