Flag carrier Oman Air has ordered 20 Boeing Co (BA.N) 737 aircraft as part of a plan to double its fleet to 70 planes by 2020, Chief Executive Paul Gregorowitsch said on Monday. Ten of the planes will come directly from Boeing and the rest from leasing companies, he added. Oman Air plans to use these aircraft to grow its domestic network, as well as key regional markets like the Gulf and India, he said. Oman Air has 36 aircraft, including 10 Airbus A330s and 21 737s.