The most important of the US orders were two orders for comparatively modern Curtiss P-36 Hawk monoplane fighters. The first was for 24 Hawk 75A-6 (with 1200 hp Pratt & Whitney R-1830-SC3-G Twin Wasp engines), 19 of which were delivered before the invasion. Of these 19, though, none were operational when the attack came. A number were still in their shipping crates in Oslo harbour, while others stood at the Kjeller aircraft factory, flight ready, but none combat ready. Some of the Kjeller aircraft had not been fitted with machine guns, and those that had been fitted still lacked gun sights.