DAYTON, Ohio—Boeinghas started the T-X flight test program for the engineering, manufacturing and development (EMD) program with the first two modified, company-funded prototypes, while the final version of the EMD aircraft remain in detailed design. 
The early test points collected by the first two T-X aircraft, which have resumed flying after a months-long hiatus, are possible because there are no outer mold line changes between Boeing’s company-funded prototypes and the EMD design.
“She flew just superb. First EMD test points went off without a hitch,” said Steve Schmidt, Boeing’s T-X test pilot.
Boeing built the first two aircraft during the competitive T-X bidding phase and totaled about 72 flights on both after a first flight on Dec. 20, 2016. The U.S. Air Force selected Boeing’s $9.2 billion bid last September to deliver a minimum of 351 aircraft and 42 ground-based training systems.
Since the contract award, Boeing modified the prototypes with a Collins Aerospace ACES ejection seat and an updated version of the oxygen generating system, among other minor changes, said Lynda Rutledge, the Air Force’s program executive officer for mobility and training. The critical design review for the final EMD version of the aircraft should be completed by year’s end, allowing Boeing to start assembly of the first Air Force-funded test aircraft.
The Air Force hopes to take advantage of Boeing’s bold bidding and design approach on the T-X to dramatically reduce the number of test points and buy up to 125 more aircraft than currently budgeted with the contractual savings, Rutledge said.
Boeing and rear fuselage supplier Saab applied an advanced form of model-based systems engineering to the design of the T-X. Instead of developing three-dimensional loads and aerodynamic models of parts of the aircraft, Boeing applied the engineering approach throughout the aircraft, including line replaceable units.
The Air Force held a test summit in early June, partly with the aim of determining how the operational test community could leverage Boeing’s approach to dramatically reduce the length and cost of flight testing, said Rutledge, who spoke to Aerospace DAILY on the sidelines of the Life Cycle Industry Days event here June 20.
Air Force officials are trying to balance that optimism with caution over Boeing’s unproven approach to the T-X design, Rutledge said. At the same time, the Air Force is eager to capitalize on Boeing’s aggressive approach on a fixed-price contract.
The conventional approach to flight testing starts with a baseline, conservative assumption, which can be loosened if test points indicate that is possible, Rutledge said. But Air Force officials now are considering taking the opposite approach on the T-X flight test program. 
“Let’s assume that we can have less [test] points and walk up that ladder quicker and if it doesn’t work, if it doesn’t prove to be right, we’ll expand,” Rutledge said. “That’s a very different way of doing it than planning for the worst case and backing off.”