The cavernous upper deck was capable of accommodating oversize cargo accessed through a very large right-side door.In addition, a typical B-52 refueling engagement profile would involve a descent that allowed the aircraft pair to maintain a higher airspeed (220–240 knots).In the early 1960s, the Tactical Air Command added General Electric J47 two twin- jet pods from retired KB-50 aerial tankers to produce the KC-97L.52-0828)[15] was adapted into the Aero Spacelines Super Guppy, a transport plane designed to carry Apollo Program rocket stages from California to Florida.It is one of two KC-97s left still in flyable condition, the other being former KC-97G 52-2718, "Angel of Deliverance", currently flown by Berlin Airlift Historical Foundation as YC-97A 45-59595.