Question: Mirza Ahmad Ispahani was the first chairman of an airline out of what main hub?

full_context: Document 1: Ispahani Public School &amp; College, Comilla: Ispahani Public School & College, Comilla commonly referred to as IPSC is a well known private educational institution on Comilla,Bangladesh. The institution offers primary, secondary and higher secondary education facilities under the Comilla Education Board. Founded by Mirza Ahmad Ispahani in 1979 the institution is widely known for its excellent results in S.S.C. and H.S.C. exams and its discipline.
Document 2: Pakistan International Airlines: Pakistan International Airlines (Urdu: ‎ ) commonly known as PIA (Urdu: ‎ ) is the national flag carrier of Pakistan. Its main hub is Karachi while Lahore and Islamabad are its secondary hubs.
Document 3: Mirza Mehdy Ispahani: Mirza Mehdy Ispahani (also known as Sadri Ispahani) (1923–2004), son of Mirza Ahmad Ispahani, was Chairman of M.M. Ispahani from 1949 till 2004. Mirza Ali Behrouze Ispahani, son of Mirza Mehdy Ispahani was elected as the Chairman of M.M. Ispahani in 2004.
Document 4: Transport in Islamabad: Islamabad is connected to major destinations around the world through Benazir Bhutto International Airport, previously known as Islamabad International Airport. The airport is the third largest in Pakistan and is located outside Islamabad, in Chaklala, Rawalpindi. In fiscal year 2004–2005, over 2.88 million passengers used Benazir Bhutto International Airport and 23,436 aircraft movements were registered.
Document 5: Benazir Bhutto International Airport: Benazir Bhutto International Airport (Urdu: ‎ , IATA: ISB, ICAO: OPRN ) is the third-largest airport in Pakistan, serving the capital Islamabad and its twin city Rawalpindi in the province of Punjab. Previously known as the Islamabad International Airport, it was renamed after the late Pakistani leader Benazir Bhutto by the then Prime Minister of Pakistan, Yusuf Raza Gillani on 21 June 2008. The airport is actually located outside Islamabad, in the area of Chaklala, Rawalpindi. Being the main airport for the Pakistani capital it often hosts officials and citizens from other nations. The airfield is shared with the transport and liaison squadrons of the Pakistan Air Force, which refers to it as PAF Base Nur Khan.
Document 6: Pakistan Civil Aviation Authority: Pakistan Civil Aviation Authority (Urdu: ‎ ) (abbreviated as CAA) is a regulatory authority, which oversees and regulates all aspects of civil aviation in Pakistan. CAA's head office is situated in Terminal-1 of Jinnah International Airport in Karachi. CAA is a member of the International Civil Aviation Organization. Safety Investigation Board (SIB) conduct air safety investigations on direction of Federal Government. Nearly all civilian airports in Pakistan are owned and operated by the CAA.
Document 7: Rahul Bhatia: Rahul Bhatia is an Indian businessman and co-founder and Non-executive director of low-cost carrier IndiGo and Group Managing Director of InterGlobe Enterprises. IndiGo airlines commenced operations in 4thAugust 2006 and had its Initial Public Offering (IPO) in October 2015. After the listing of the airline on the Indian stock exchanges BSE and NSE, "Forbes" magazine declared him the twentieth richest person in India (jointly with his father Kapil Bhatia), with a net worth of $3.1 billion. India Today magazine ranked him #17th in India's 50 Most powerful people of 2017 list.
Document 8: Air India: Air India is the flag carrier airline of India. It is owned by Air India Limited, a government-owned enterprise, and operates a fleet of Airbus and Boeing aircraft serving 90 domestic and international destinations. The airline has its hub at Indira Gandhi International Airport, New Delhi, alongside several focus cities across India. Air India is the largest international carrier out of India with an 18.6% market share. Over 60 international destinations are served by Air India across four continents. Additionally, the carrier is the third largest domestic airline in India in terms of passengers carried (after IndiGo and Jet Airways) with a market share of 13.5% as of July 2017. The airline became the 27th member of Star Alliance on 11 July 2014.
Document 9: Mirza Ahmad Ispahani: Mirza Ahmad Ispahani (1898–1986) was a Perso-Bengali businessman and the patriarch of the Ispahani family based in Chittagong. He was the founder of Orient Airways and the first chairman of Pakistan International Airlines (PIA).
Document 10: Ispahani Islamia Eye Institute and Hospital: The Ispahani Islamia Eye Institute and Hospital is an ophthalmological hospital in Dhaka, Bangladesh. The hospital was founded by Bangladeshi philanthropist Mirza Ahmad Ispahani in 1960.
Document 11: Vision Air International: Vision Air International is a passenger and cargo charter airline based at Jinnah International Airport, Karachi, Pakistan. Vision Air International registered as a Private Limited Company in June 2006 and in 2007 had already acquired its Air Charter License for Passenger and Cargo, Domestic and International operations. Having initially operated Boeing 737-200 and -300 passenger aircraft Vision is now primarily focused on air cargo and operates Boeing 737 freighter aircraft. Vision transports the majority of Pakistan’s air courier material on its nightly scheduled flights internally within Pakistan.
Document 12: Ispahani Public School &amp; College: Ispahani Public School & College, Chittagong commonly referred to as IPSC is a well known private educational institution on Zakir Hossain Road in Chittagong, Bangladesh. The institution offers primary, secondary and higher secondary education facilities under the Chittagong Education Board. Founded by Mirza Ahmad Ispahani in 1979 the institution is widely known for its excellent results in S.S.C. and H.S.C. exams and its discipline.
Document 13: Ispahani Hangar: The Ispahani Hangar is a Pakistan International Airlines wide-body aircraft maintenance hangar at the Jinnah International Airport in Karachi, Pakistan. It was named in honour of Mirza Ahmad Ispahani, the first and longest serving chairman of Pakistan International Airlines (PIA). The hangar for wide body and narrow body aircraft with a supporting airframe overhaul shop was completed and commissioned in 1968.
Document 14: Malik Riaz: Malik Riaz Hussain (Urdu, Punjabi: ; born February 8, 1954) is a Pakistani businessperson, billionaire and philanthropist. He is the founder and chairman of Bahria Town, the largest privately held real estate development company in Asia. Riaz is currently the 7th richest person in Pakistan, with an estimated wealth of over a billion US$, he is one of Pakistan's most prominent philanthropists.
Document 15: Mirza Ali Behrouze Ispahani: Mirza Ali Behrouze Ispahani was a Bangladeshi businessman from the Ispahani family and the chairman of M. M. Ispahani Limited.
ground_truth: Karachi