On 7 February 1937, all services were transferred to Croydon Airport, after surfaces at Gatwick became water-logged due to heavy traffic on immature turf and drains that collapsed; some training operations remained there. In March 1937, the first four of seven Lockheed 10 Electras were delivered. On 12 August 1937, Scottish Airways Ltd was formed to merge the operations of Northern & Scottish Airlines with Highland Airways Ltd, and British Airways Ltd held a 50% stake. On 29 May 1938, most aircraft and services were transferred from Croydon to Heston, due to congestion and unpredictable fog, but night mail operations continued from Croydon. On 3 September 1938, the first of nine Lockheed 14s was delivered.