In 2007, Rolls-Royce shook up the US fighter engine business when it, and not Pratt & Whitney, was selected to demonstrate the next leap in combat-aircraft powerplant capability under the Air Force Research Laboratory's Adaptive Versatile Engine Technology (ADVENT) program.
Today, it's Pratt's turn to fight back, and the company has been selected over Rolls for AFRL's follow-on Adaptive Engine Technology Development (AETD) program. General Electric, the other winner back in 2007, gets to stay on for AETD, which will take the variable-cycle technology being developed under ADVENT to the next level of maturity.
ADVENT core (Photo: GE Aviation)
In the intervening years, a GE/Rolls team fought and lost a bitter battle to provide a competitive alternative to Pratt's F135 engine powering the F-35 Joint Strike Fighter. And for a while it looked like Pratt's supporters in Congress might kill the AETD program to prevent it becoming another competitor to the F135. It will, but not for many more years.
Pratt seems more comfortable with competition to power the F-35 when it is years away, and when it has a place at the table through AETD. But the real prize will be powering whatever the US Air Force and Navy decide they want as "sixth-generation" fighters. The Navy is looking at entry into service in 2028, and the Air Force at 2032, but risk reduction has to start now so that engine development can begin around 2020 to ensure it will be ready.
ADVENT is demonstrating high pressure-ratio core and adaptive-fan "third stream" low-pressure system technology that will enable thrust specific fuel consumption to be reduced 25% while military (dry) power is increased 5% and maximum (reheat) thrust 10% over the F135 -- all in an engine that can fit in an F-35 "with only modest modification".
The GE and Rolls ADVENT engines demonstrators will run next year. AETD will take the variable-bypass fan and three-stream flow architecture and add highly integrated controls and a stealthy serpentine exhaust system (not part of ADVENT) and mature it to technology readiness and manufacturing readiness levels of 6 by 2017, ready to enter engineering and manufacturing development when required.