For several weeks prior to the German invasion of the Netherlands, Dutch airline KLM, operated a direct, over-water, twice-weekly DC-3 service from Amsterdam to Portugal avoiding French, British, and Spanish airspace to connect with the new Pan American flying boat service from the US to Lisbon.
When Germany invaded in May 1940, KLM had several airliners en route outside the Netherlands.
Some managed to fly to Britain while others stranded east of Italy continued to link British and Dutch territories from Palestine to Indonesia and Australia.
The British government interned the Dutch aircraft at Shoreham Airport.
After negotiations, the Air Ministry and the Dutch government-in-exile contracted to use the KLM aircraft and crews to replace de Havilland Albatross aircraft on a scheduled service between Britain and Portugal, which BOAC started in June 1940 from Heston Aerodrome.

After the initial reservations about using Dutch crews were overcome, all-Dutch crews were used, although the flights used BOAC flight numbers and passenger handling.
The KLM contingent was housed at BOAC's Whitchurch base.
For several weeks prior to the German invasion of the Netherlands, Dutch airline KLM, operated a direct, over-water, twice-weekly DC-3 service from Amsterdam to Portugal avoiding French, British, and Spanish airspace to connect with the new Pan American flying boat service from the US to Lisbon. When Germany invaded in May 1940, KLM had several airliners en route outside the Netherlands. Some managed to fly to Britain while others stranded east of Italy continued to link British and Dutch territories from Palestine to Indonesia and Australia. The British government interned the Dutch aircraft at Shoreham Airport. After negotiations, the Air Ministry and the Dutch government-in-exile contracted to use the KLM aircraft and crews to replace de Havilland Albatross aircraft on a scheduled service between Britain and Portugal, which BOAC started in June 1940 from Heston Aerodrome.
After the initial reservations about using Dutch crews were overcome, all-Dutch crews were used, although the flights used BOAC flight numbers and passenger handling. The KLM contingent was housed at BOAC's Whitchurch base.
BOAC Flight 777