RAF No. 155 Squadron operated Westland Whirlwind HR4 at Kuala Lumpur approximately 1955–59. No.155 Squadron was formed at Chingford on 14 September 1918 as a bomber unit with D.H.9As after an earlier decision to form at Feltham was abandoned. The war ended a few weeks later and it did not become operational, disbanding on 7 December 1918.
On 1 April 1942, No.155 reformed at Peshawar as a squadron but did not receive its first Mohawks until mid-August owing to the necessity to modify these aircraft for operational use. Air defense and convoy patrols began in September off Madras and in October the squadron moved to Bengal and detachments began operating over Burma. Reconnaissance, ground attack and bomber escort missions occupied the squadron until January 1944, when it finally replaced its Mohawks with Spitfires. Initially these were used for air defense duties until the Japanese air force in Burma ceased to be a threat. Ground attack missions and escort for transport missions then became its main tasks, the Spitfires carrying 500-lb bombs during the last months of the campaign. In mid-September 1945, the squadron flew to Singapore soon after the Japanese surrender and in February 1946, moved to Sumatra to provide tactical support for the Army units there until disbanded on 31 August 1946.
On September 1954, No.155 reformed at Kuala Lumpur with Whirlwind helicopters and provided transport and casualty evacuation support for the Army and police in Malaya during their flight against Communist guerrillas in the jungle. On 3 June 1959, it merged with No.194 to form No.110 Squadron.