Aircraft manufacturers, Airbus SAS and Boeing Co. have said that they are considering an upgrade to their most popular jets with different engines to cut fuel consumption and buy time to design all-new successors, Bloomberg has reported. Engine makers including General Electric Co. and Pratt & Whitney say they could make a turbofan engine available as soon as 2016 which would reduce fuel consumption and noise. Redesigning planes to accommodate the engine would cost less than $1bn, compared with $10bn to create a completely new model.