On 12 June 2021, Hannan took over command of the Bangladesh Air Force from his predecessor Masihuzzaman Serniabat.

[8][9] Hannan served in the United Nations Protection Force in Bosnia Herzegovina (UNPROFOR) in 1995.

He also led the BAF Contingent (BAN AIR-4) in the United Nations Mission in the Democratic Republic of the Congo (MONUC) in 2006–07.

[citation needed] Air Chief Marshal Shaikh Abdul Hannan has been accused of embezzling more than $245 million from Bangladesh Air Force’s annual budget and siphoning out of the country to Canada, the USA and the UAE.

[15] Bangladesh’s anti-corruption commission has been investigating the matter after a formal complaint has been filed by a group of lawyers.