Built in their spare time

KZ began as a hobby. Viggo Kramme, a naval air service mechanic, ran a small workshop at Kastrup airport; Karl Gustav Zeuthen, a civil engineer, was learning to fly there. Zeuthen drew an aeroplane, and with friends they built it in their spare time; the KZ I flew in February 1937. Backed by Gunnar Larsen, managing director of the engineering group FLSmidth, they founded Skandinavisk Aero Industri on 1 August 1937, and their designs carried the initials KZ.

Ambulances under occupation

The German occupation banned private flying, but SAI kept working. It built a glider prototype, wind-turbine blades for FLSmidth and even an electric car, and in May 1944 delivered two twin-engined KZ IV air ambulances to the Zonen rescue corps. As soon as the war ended it put the KZ III two-seater into production, building 63 in 1946, and followed it with the four-seat KZ VII, 56 of which were built; ten served the Danish military until 1977.

Hard currency and a fire

The boom was short. The KZ VII depended on imported engines paid for in hard currency, so 80 per cent of output had to be exported, and when foreign buyers could not find dollars in 1947, sales stopped; a fire destroyed 22 unfinished aircraft the same year. The KZ X artillery spotter for the army suffered fatal accidents, and in 1954 the founders closed the factory after about 200 aircraft of 11 types. Many KZ IIIs and VIIs still fly.

Fabrieken

• Kastrup workshop · Copenhagen Airport, Kastrup — Kramme’s workshop from 1935
• FLSmidth facilities · Aalborg — Production moved here for a time
• Sydhavnen factory · Copenhagen — Own factory after 1943

Mensen

• Viggo Kramme · co-founder, technician — 1905–1984
• Karl Gustav Zeuthen · co-founder, engineer — 1909–1989
• Gunnar Larsen · backer — Managing director of FLSmidth