Masud had the area responsibility of defending the airspace border of East-Pakistan but resigned from his commission after the military operation took place on 26 March 1971, and left the command to Air Cdre Inamul Haq on 30 March 1971.
Muhammad Masud Zafar was born in Gujranwala, Punjab in British India into a Punjabi family in 1927. His father, Zafar Hussain, was an alumnus of Punjab University and was a civil officer in the Indian Railways who later headed the Railway Board in Delhi when the family was moved before the partition.
In 1942, he did his matriculation from Model High School and joined the Royal Indian Air Force (RIAF) with a dream of becoming fighter pilot. In 1946, he gained commissioned in the RIAF as P/O (2nd Lt.) and joined the Pakistan Air Force after the independence of Pakistan as a result of the partition of India on 14 August of 1947. He did not participated in the first war with India in 1947 as he joined the air force faculty.
In 1948, F/O Masud joined the faculty of Air Force Academy in Risalpur where he began flight instructions to young air force cadets. In 1952, he did further training on flight management and qualified as a fighter pilot when he completed a Fighter Leader Course at the RAF.
In 1957-58, Wg.Cdr. Masud (Lt.Col.) was tasked by Air Cdr-in-C, Air Marshal Asghar Khan, to organize, train, and lead an aerobatics team, the PAF Sherdils, of 16 F-86 Sabre jets that would set a workd record, validating the PAF’s place among the well- regarded air arms of the world.
Gp. Capt Masud's first command assignment was included as base commander Sargodha Air Force Base, which would emerged him as the top hero of the 1965 war.
In 1965, he actively participated in second war with India when he led a team of fighter pilots, including Fl.Lt Mervyn Middlecoat, Sq. Ldr. Cecil Chaudhry, and Sq. Ldr. MM Allam, against the Indian Air Force. Gp. Capt Masud flew against the Indian Air Force in Sargodha Sector with great courage and was regarded as an ace fighter for his ability in dogfight against the Indian pilots.
From 1966–69, Gp. Capt. Masud continued his role as a flight instructor with the Air Force and was appointed in the Air AHQ as Director-General of Air Operations (DGAO). In 1969, Gp. Capt. Masud was promoted to one star rank, Air Commodore (Brigadier), and was being speculated as a probable future air force chief once the retirement of Air Marshal Abdul Rahim Khan.
In 1970, Air Cdre (Brig) Masud was appointed as an AOC of the Eastern Air Command, and was assigned in Dhaka as top air commander by Yahya administration. Air Cdre Masud established the presence of the air force with higher measure of courage and, since spending an year in East, Air Cdre Masud reached to the conclusion that, with increasing distress, the rapidly mounting military-political threat that none of the power wielders seemed able or interested to resolve."
In April 1971, Air Cdre Masud relayed his concern to then-Governor East Vice-Admiral Syed Mohammad Ahsan and his Chief of Staff Lieutenant-General Yakob Ali Khan, who decided to call upon President General Yahya Khan to visit East Pakistan. Air Cdre Masud was in clear view that situation was such that the army could not hold the ground of it, and had lobbied for supporting the Ahsan-Yakob Mission for resolving the peaceful solution.
In March 1971, President Yahya Khan finally arrived in Dhaka and chaired a meeting at the Eastern Command HQ where Air Cdre Masud argued in favor of political solution, noting that "in the prevailing military imbalance, a semi-autonomous East Pakistan was far preferable to the certainty of a military defeat in the event that India decided to intervene". During the meeting, President Yahya interjected several times and was in view of agreeing with Air Cdre Masud's view and supported his stance by quoting: "You must [sic] surely know that I too do not want a war and am doing my best to persuade Mujib and Bhutto to find a way out of the crisis."
On 7 March 1971, Governor East Vice-Admiral Syed Mohammad Ahsan and his Chief of Staff Lieutenant-General Yakob Ali Khan were relieved of their respected post, leaving to Lieutenant-General Tikka Khan who initiated the massive military crackdown after the raid in the Dhaka University. Upon their retirement, Air Cdre Masud took the command of the Eastern Command but he suffered with high-level of local defections in his own staff when Air Cdre Masud's chief of staff Gp Capt A. K. Khandker defected to India in a official plane in May 1971. This was followed by the defection of Wg. Cdr Muhammad Hamidullah and Sq/Ldr M.G. Tawab who joined the Indian Air Force against the PAF in East. Air Cdre Masud refused to send and dispatch the No. 14 Squadron Tail Choppers under Sq.Ldr. PQ Mehdi for aerial support for searchlight.
During this time, Air Cdre Masud made many contacts with President Yahya Khan but was unable to reach to him, eventually deciding to visit in Army GHQ in Rawalpindi. Air Cdre Masud handed over the air command to Air Cdre Inamul Haque and arrived in Pakistan but was unable to hold the meeting with President Yahya which eventually led Air Cdre Masud disheartened and frustrated.
Despite urging against the early and premature retirement, Masud tendered his resignation from the Pakistan Air Force, which attracted the news media correspondents who tried getting his opinion but he declined to comment.
After seeking retirement on July 1971, Masud worked as civilian flight instructor for the Pakistan International Airlines which he remained associated his entire life.
He was married to a German national, Elizabeth, who worked as technician at Siemens Engineering in 1959; his wife died in 2004. He had one son, Salaar, who became a Software engineer. Masud died due to a cardiac arrest in PAF Hospital in Islamabad and is buried in PAF cemetery in Islamabad, where his wife was also laid to rest next to him in 2003.