Adaptive Versatile Engine Technology

The ADaptive Versatile ENgine Technology (or ADVENT) program is an aircraft engine development program run by the United States Air Force with the goal of developing an efficient variable cycle engine for next generation military aircraft in the 20,000 lbf (89 kN) thrust class.

Objective
The objective of ADVENT is to develop an engine that is optimized for several design points, rather than the traditional single point. Instead of having an engine that is designed solely for high speed (like many current fighter engines are) or for high fuel efficiency (like many current commercial engines are), the final ADVENT engine would be designed to operate at both those conditions. Specific goals include reducing average fuel consumption by 25% and reducing the temperature of cooling air produced by the engine.

History
The ADVENT program is one of several related development projects being pursued under the Air Force's Versatile Affordable Advanced Turbine Engines (VAATE) program. After being announced in April 2007, Rolls-Royce and GE Aviation were awarded Phase I contracts in August 2007 to explore concepts, develop and test critical components, and begin preliminary designs of an engine.

In October 2009, Rolls-Royce was awarded the Phase II contract to continue component testing and integrate the developed technologies into a technology demonstrator engine. GE Aviation was also awarded funds to continue development of their technology demonstration core, which was unexpected as the ADVENT program had originally called for a single contractor to be selected for Phase II.

USAF officials have denied that the program is an attempt to create a backup engine program for the F-35.

Operational testing of the engine is expected to begin in 2013.

Applications
The ADVENT engine was originally targeted at the Air Force's 2018 Next-Generation Bomber, but uncertainty in that program has led Rolls-Royce (RR), one of the primary developers involved with the project, to predict that the ADVENT engine will be better suited for a potential 2020 engine upgrade for the F-35 Lightning II. RR, who is partnered with GE Aviation on the embattled F136 alternate engine for the F-35, has suggested that the ADVENT development contracts are all the more reason to continue the F136, as any engine upgrade from Pratt & Whitney (makers of the F135 engine currently used in the F-35) would have to be separately funded, either internally or to additional government cost.

In light of this threat, Pratt has funded an adaptive fan variant of its F135, that may qualify for the follow-on Adaptive Engine Technology Development (AETD) program under the US Air Force Research Laboratory. GE was chosen to continue its ADVENT work into the AETD program. Pratt & Whitney was selected over Rolls Royce to continue along with GE for the AETD program to mature fuel-efficient, high-thrust powerplants.