The Boeing [BA] and Saab Red Hawk training aircraft for the U.S. Air Force has received an “unprecedented” level of interest from potential foreign customers who may want the standard trainer or a variant of the aircraft as a fighter attack jet, Chuck Dabundo, the Boeing vice president of T-7 programs, told reporters on Sept. 14.

Dabundo also said that the Red Hawk has benefited from a digital engineering approach, which has allowed the program to resort to a “shimless” build and to resolve possible “black box” integration problems early on.

“One of the mantras of the program since pre-contract has been breaking the norm,” he said. “We’ve been able to consistently break that norm by leveraging digital engineering and digital manufacturing to the full extent possible. It really starts with high fidelity models of the structure and the systems that are fully integrated. That has really changed the way we design, the way we drive that integration very early in the process. We do virtual reviews of the structure and systems. We proved out that new norm by going from concept to flight in 36 months. I think that approach has really resonated with the Air Force.”

In her kick-off address to the Air Force Association’s virtual Air, Space, and Cyber (vASC) conference on Sept. 14, U.S. Air Force Secretary Barbara Barrett named the Red Hawk as the first Air Force system to carry the “e” prefix designating digitally engineered systems. Previously known as the T-7A, the aircraft will now be the eT-7A.

In September, 2018, Boeing and Saab won a potentially $9.4 billion Air Force contract for 46 simulators and 351 aircraft, which are expected to replace the service’s aging T-38 Talon fleet. The award was the culmination of five to six years of work by Boeing, Dabundo said on Sept. 14.

Dabundo said that Boeing was the only competitor to propose a “purpose-built aircraft.” and that the company built and flew two production representative jets (PRJs) before the contract award.

Boeing is using those jets to reduce risk in the upcoming engineering and manufacturing development phase. The building of the PRJs also will result in fewer touch labor hours required for production aircraft, Dabundo said.

Steve Schmidt, the Boeing eT-7A test pilot, said that Boeing just finished Phase I of the flight test program with the PRJs, which included inverted flight, envelope expansion, and subsystem verification. One of the PRJs also flew to Andrews AFB, Md., for the change of command ceremony for incoming Air Force Chief of Staff Gen. Charles Q. Brown last month, he said.

Phase 2 of the flight test program will feature cargo pod and high angle of attack testing and forcing the aircraft out of control to ensure it can safely recover.