Mr. Epstein presents the genesis of the concept of “geared Turbofan engine” against the background of the evolution in aircraft engines, from the first reactors to the double-fluxes and then with increasing dilution rates in order to reduce fuel consumption, in particular for medium to large civilian carriers. It took 25 years of perseverance and $1 billion to arrive at the very high efficiency (99.5%) and high reliability (heavy maintenance every 20 years) reducer, of “seemingly simple” design (13 main parts only), that equips the engine of the A320 NEO.
The introduction of the reducer does not simply increase the dilution rate but generates a number of benefits where some might have predicted disadvantages.