[12] His grandfather Capt Sant Singh had fought in World War II as a captain of the British Indian Army.

He thereon joined Rashtriya Indian Military College, Dehradun, and later graduated from National Defence Academy, Pune.

[15][16] Dhanoa was commissioned into the fighter stream of the Indian Air Force in June 1978.

Dhanoa was Commanding Officer of a front line ground attack fighter squadron during the Kargil Conflict in 1999.

Under his leadership the squadron devised innovative methods of night bombing at high altitudes which had never been attempted before.