The U.S. Air Force has taken another step toward replacing its aging fleet of T-38 training aircraft, releasing a draft request for proposals (RFP) to the competitors that provides incentives for exceeding certain performance requirements for the next-generation T-X.
This is the first time the Air Force has released a version of the full RFP package for the T-X, after issuing several iterations of the requirements for industry review and comment. The key difference this time is that the Air Force is now incentivizing industry to exceed the threshold requirements for specific performance aspects, including high-g maneuvering, high angle-of-attack maneuvering and aerial refueling.
For the aircraft’s crucial g-capability requirement, this means that for every 0.1 g above the 6.5 g threshold and up to the 7.5 g objective, the offeror will receive a bonus, according to the draft RFP posted online July 26. In other words, for two T-X proposals that are the same price, the proposal with the higher sustained-g capability will be rated higher overall. Depending on the cost of the competing solutions, a proposal with a slightly higher price tag for a greater sustained-g capability could get the better rating.
The Air Force settled on this method of evaluating the proposals after a long conversation with industry about baseline and higher-level requirements that Secretary Deborah Lee James called “unprecedented.” The Air Force’s aim is to do a cost-capability analysis and tradeoff for T-X as part of a service-wide effort to bring down the cost of acquisition programs, called “bending the cost curve,” James said during an event in Washington just hours ahead of the draft RFP release.
“Based on the multiple reviews with industry, the Air Force now has a much better appreciation of the potential value of performance above threshold capability,” said Air Force spokesman Maj. Rob Leese July 27.  “Therefore, in our evaluation of proposals we will incentivize specific performance aspects, allowing for additional capabilities that will improve the effectiveness and efficiency of pilot training for decades to come.”
The draft RFP, which will be followed by a finalized version by the end of the year, is driving the decisions of four industry teams competing to build the 350 T-X aircraft and associated training systems that will train the next generation of Air Force pilots flying theF-22 and F-35. The T-X contract will also provide the winning team an inside track to any number of international customers who buy the F-35 around the globe.
The Air Force anticipates awarding a contract in 2017, with initial operating capability planned in 2024.
Although a contract award is still a year away, it’s already a crowded field. A Boeing/Saabteam and a Northrop Grumman-led coalition that includes BAE Systems and L-3 are offering clean-sheet designs; meanwhile Korea Aerospace Industries (KAI) and Lockheed Martin are teamed on the T-50A, and Raytheon, Leonardo and CAE will offer the T-100. Textron Airland had hoped to offer its Scorpion design, or a modified version of the jet, but earlier this year determined developing a proposal that could meet the T-X requirements would be cost-prohibitive.
The system specifications included in the draft RFP hew closely to the requirements the Air Force released last year. That document identified three key performance characteristics for the new aircraft: sustained g, simulator visual acuity and performance, and aircraft sustainment.
The sustained g specification, which is unchanged from last year, is the most controversial. Rather than the common definition of sustained g-force as being achieved at constant speed and altitude, the T-X requirement is to perform a specific maneuver in which a minimum of 6.5g is sustained through a 140-degree turn. The Air Force is requiring a minimum of 6.5g sustained through the turn, with at least 80 percent fuel at 15,000 ft., and a desired objective requirement of 7.5g. The maneuver should start at 15,000 ft., and finish no lower than 13,000 ft., while losing no more than 10% of its initial speed.
The Air Force’s announcement that it will incentivize a higher g capability seems to favor the Lockheed-KAI T-50A. The Raytheon-Leonardo T-100 is compliant with the requirement but “on the line,” chief test pilot Enrico Scarabotto told Aviation Week last year. However, Raytheon’s Dan Darnell more recently said the aircraft “easily meets and exceeds” the minimum g, instantaneous turn and sustained turn rates. During a briefing at the Farnborough International Airshow earlier this month, Darnell called doubts that the aircraft could meet the performance characteristics “a lot of urban myth and legend.”
Lockheed spokesman Rob Fuller said there were no surprises in the draft RFP.
Required aircraft availability is also unchanged from the 2015 requirements document: at least 80%. Other requirements include in-flight refueling from both a KC-135 and KC-10 tanker boom; a 10% reduction in fuel usage from the T-38; a takeoff distance no greater than 6,400 ft. using an 8,000-ft. runway with a 10-kt tailwind and 7,464-ft. density altitude; and a landing ground roll distance of no greater than 7,000 ft. on an 8,000-foot runway with a 10-kt tailwind and 7,464-ft. density altitude.
Each airframe must be able to operate for 8,000 flight hours, while the fleet should be designed for 22 years of service life assuming a maximum utilization rate of 30.3 hr. per month, according to the draft RFP.