Boeing 757-200M

The 757-200M, a convertible version capable of carrying cargo and passengers on its main deck, entered service with Royal Nepal Airlines in 1988. Also known as the 757-200 Combi, the type retains the passenger windows and cabin doors of the 757-200, while adding a forward port-side cargo door in the manner of the 757-200PF. Kathmandu-based Royal Nepal Airlines, later renamed Nepal Airlines, included the convertible model as part of an order for two 757s in 1986.
Nepal Airlines ordered the 757-200M to fulfill a requirement for an aircraft that could carry mixed passenger and freight loads, and operate out of Tribhuvan International Airport in the foothills of the Himalayas. Patterned after convertible variants of the 737 and 747, the 757-200M can carry two to four cargo pallets on its main deck, along with 123 to 148 passengers in the remaining cabin space. Nepal Airlines' 757-200M, which features Rolls-Royce RB211-535E4 engines and an increased MTOW of 240,000 pounds (109,000 kg), was the only production example ever ordered.
In October 2010, Pemco World Air Services and Precision Conversions launched aftermarket conversion programs to modify 757-200s into 757 Combi aircraft. Vision Technologies Systems launched a similar program in December 2011. All three aftermarket conversions modify the forward portion of the aircraft to provide room for up to ten cargo pallets, while leaving the remaining space to fit around 45 to 58 passenger seats. This configuration is targeted at commercial charter flights which transport heavy equipment and personnel simultaneously. Customers for converted 757 Combi aircraft include the Air Transport Services Group, National Airlines, and North American Airlines