sentences:  On 1 April 1940, British Airways Ltd and Imperial Airways were officially merged as a new company, British Overseas Airways Corporation (BOAC).After the surrender of the Netherlands on 14 May 1940, several KLM aircraft evaded capture, and converged on the UK.On 4 June 1940, BOAC started a Heston to Lisbon service, using DH.91 Albatrosses, to connect with transatlantic services of Pan American World Airways (Pan Am) that used Boeing 314 flying boats.