KLM's first multi-engined aircraft, the large FK.33 was designed by Frits Koolhoven for the NVI company. It was intended for evening services, flown by a crew of two pilots and a navigator. The three engines were uncovered. The pusher on the wing was not an afterthought although the aircraft did initially fly with two engines. Note the ladder behind the cabin. Seen here over Rotterdam, 'Dikke Dirk' (Fat Derek) was not a succes and only flew 85 hours in KLM service between December 1925 and mid-1927 when it was sold as D-1250. The c/n was then registered as 501, and later changed to 1001.