sentences:  Some days later, 6 February, it was again "Atalanta" G-ALHK which returned the newly acceded Queen Elizabeth II to England upon the death of her father, King George VI.Rolls-Royce also developed a quieter 'cross-over' exhaust system for the DC-4M, the modifications being supplied in a kit allowing installation on the aircraft by the operator.The engine thus modified became the 'Merlin TMO' in contrast to the unmodified engine, the Merlin TML - Transport Merlin L. The modified exhaust conferred an increase in horsepower over the unmodified system of 38 hp, resulting in a 5 knot improvement in true air speed.