He was of one of the contestants who participated in a competition set by the Aga Khan in 1929, who offered a prize to the first Indian to fly the England-India journey (either way), solo and within a one-month time frame.

In addition, with a scholarship from the Government of British India, he studied aeronautical engineering and learnt to fly[5] while a member of Bristol and Wessex Aeroplane Club.

[3] In November 1929, keen to promote aviation, the Aga Khan, 48th Imam of the Ismaili sect of Muslims[3] announced a prize of £500[3] to the first Indian pilot who could fly solo between England and India.

[9] It was at his third attempt that he completed the journey from Croydon to India, starting off on 8 April 1930,[12][13] and was the first to land at RAF Drigh Road, Karachi on 9 May 1930, one day after the one-month deadline.

[16] Singh received a hero's welcome upon his return to Bristol when he was greeted at the station by his landlords Mr and Mrs Leate and their daughters Jean and Margaret with garlands of flowers.

[3] As a result of his achievement, Maharaja Bhupinder Singh, ruler of Patiala state, appointed Singh as his chief personal pilot and he subsequently became the first Indian to fly solo the journey from England to South Africa, albeit following his fourth attempt to do so and after a crash which resulted in a broken leg and a wrecked "Miss India".

[17] Singh joined the Indian Air Force Volunteer Reserve as a pilot officer at the onset of the Second World War.

He was one of the 24 Indian pilots seconded to England for training and action, where he was affectionately referred to by colleagues as "Chacha Man Mohan Singh" (uncle).

After withdrawing from Singapore due to the extent of their losses in the Japanese invasion, his squadron moved to Java and then to Broome, Western Australia, where he contributed to the rescue of Dutch civilians.

[3] His story is recounted in Defence of Europe by Sikh Soldiers in the World Wars, written by his nephew Mohindra S Chowdhry and published by Troubador in 2018.