The most famous Comet of all! G-ACSS named Grosvenor House after the hotel of the owner of the plane A.O. Edwards. The plane was flown by C.W.A. Scott and Tom Campbell Black in the London to Melbourne race and arrived first in Melbourne, winning the speed contest. It would have won the handicap race too but for the rule that only one title could be one by any one plane. The first place in the handicap race thereby went to the Douglas DC-2 "De Uiver" owned by the Dutch airline KLM.

Grosvernour House was painted bright red and recent evidence suggests that the lettering was silver and not white as many sources say.

After the race G-ACSS was acquired by the Air Ministry and painted aluminum. It got the RAF serial K-5084. During the tests at the RAF at Martlesham it twice suffered a collapsed undercarriage. After the first collapse it was fitted with enlarged air intakes. After the second crash in September 1936 it was sold as scrap. 

It was bought by F.E. Tasker who had the aircraft rebuilt and fitted with Gypsy Six series II engines. It was painted pale blue or light grey with dark blue accents (according to one source "Morning Mist" & Blue) and named "The Orphan". In this guise it came fourth in the 1937 Marseilles-Damascus-Paris race and second in the 1937 King's Cup.

In November 1937 it tried to break the out and home record to the Cape named "The Burberry". It succeeded in lowering the record to 15 days and 17 hours. 

In February 1938 it left for Australia named "Australian Anniversary" from which it returned in March 1938. 

For the next 13 years it was stored. In 1951 is was restored to static condition and displayed at the De Havilland company premises. In 1965 it was donated to the Shuttleworth Trust and brought to Old Warden. There the restoration to flying condition began culminating in the first flight of G-ACSS for 49 years in 1987. It flew until the closure of Hatfield airfield in 1993 but was kept in taxiable condition at Old Warden. The extension of the runway there lead to a complete overhaul of the aircraft and it will take to the air again in 2002.