The winter of 1942-43 presented major problems all along the North Atlantic Transport Route. A high accident rate due to weather was experienced beginning in September 1942 and it continued to climb. On 22 November Air Transport Command suspended the transportation of passengers across the North Atlantic for the duration of the winter. The operation of two-engine transports beyond Iceland already had been forbidden. Some ferrying, chiefly of long-range aircraft, continued into December, as did the transport operations of C-54 Skymasters and C-87 Liberators under contract with TWA and American Airlines, but by mid-December the North Atlantic Transport Route had been virtually closed down for the winter