Stadium seating

Lon Nordeen provides an overview of Boeing’s BTX-1, the company’s contender for the US Air Force T-X programme

MILITARY BOEING BTX-1

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“Over time the requirements evolved. We rapidly built a cohesive team with Saab and our other supply base partners; that is not always easy to do.”

The US Air Force has been flying the Northrop T-38 jet trainer for its advanced pilot training programme since the early 1960s.ffIt has been a great advanced trainer but many of the T-38s have been flying for over 50 years and have been rebuilt many times.

Today the T-38C only meets twelve of the 18 major US Air Force training requirements for the advanced phase of the undergraduate pilot training programme designed to produce qualified pilots to effectively fly fighters and bombers. Back in early 2015 Brigadier General Dawn Dunlop, the then Director of Plans, Programs and Requirements, Air Education and Training Command (AETC), commented the T-38C is: “no longer a practical trainer to prepare air force pilots for newer, more advanced aircraft”.

Even if the T-X programme unfolds on schedule, initial operational capability for the new training system will not occur until 2024. T-X full operational capability is scheduled for 2034 meaning that some T-38Cs will need to soldier on in the advanced training role for another 16 years or more!

T-X requirements

The replacement programme for the T-38 was initiated by the US Air Force in 2010 and the first draft requirement documents were released in 2012. In March 2015, revised T-X requirements were released. They included high performance capability; a need to sustain a minimum 15 seconds at 6.5g and an objective 7.5g so students can experience fighter turn rates and high G levels.

Cockpits, which effectively prepare students for fifth-generation fighters driven by high capacity mission computers, software, avionics and data links to allow for synthetic sensors, in-flight training and playback.

Boeing’s contender is more than a trainer aircraft but a training system with advanced ground-based training devices and student tracking systems.

Overall capability of the simulator system provides high-fidelity training to reduce the number of flight hours required for each student, saving all-important defence budget dollars.

On December 30, 2016 the US Air Force released the final requirements for its T-X programme in an offcial request for proposal which called for 350 T-X trainer aircraft and 46 ground-based training systems.

An estimate of the programme’s research and development phase was costed at $1.5 billion, with a $16 billion procurement price tag. Since those cost estimates were released the US Air Force focused more on total vs procurement cost and released an estimated life cycle cost of $35.3 billion or less over 20 years.

As of May 2018, final T-X contenders appear to be Boeing, Lockheed Martin and Leonardo DRS. The winning contender’s customer, the US Air Force, plans to base the T-X at five of Air Education and Training Command’s bases; Columbus in Mississippi, Laughlin, Randolph and Sheppard all in Texas, and Vance, Oklahoma. Ultimately, each aircraft is projected to fly 350 hours per year.

Partners

In an interview with AIR International, Boeing’s T-X programme manager, Ted Torgerson, discussed the background to, and the status of the company’s contender, the BTX-1 model, imaginatively dubbed T-X: “The US Air Force has reviewed our proposal [a joint venture with Saab] and has asked a series of questions, the first of which were submitted last December, with the most recent received in May. We have answered all of their questions. Commander of the Air Education and Training Command, Lieutenant General Kwast has confirmed the Air Force is on track for a July 2018 contract award, so we would expect to receive, and quickly respond to, the final proposal revisions very shortly.”

Torgerson continued: “Boeing considered its experience with training systems, upon which it relied as it analysed various aircraft in order to determine which might meet the projected T-X requirements, including the T-45 Goshawk [a version of the BAE Systems Hawk jet trainer]. In the end, as you recall the Hawk dropped out”.

Back in November 1981, the then McDonnell Douglas, teamed with the then British Aerospace, was selected as the winner of the US Navy’s VTX-TS programme, which resulted in the development of the T-45 Goshawk carrier capable jet trainer, 221 of which were delivered between 1988 and 2009. The VTX-TS programme also included ground-based trainers, a training integration system and contractor logistics support. The T-45A entered service in 1991 and is currently projected to remain in service beyond 2030 as the primary aircraft used to train all US Navy and US Marine Corps fighter pilots, instruct Naval Flight Offcers and train students from a variety of naval air arms.

Torgerson added: “We talked with Saab and discussed if, together, we could offer an affordable solution using a modified existing design to win the US Air Force programme. In the end we determined we were not able to use an existing Saab aircraft [the JAS 39 Gripen]. So, we talked with other aircraft manufacturers about offthe shelf options. Once we saw the evolving US Air Force trainer requirements, programme timing, we decided we had enough time to create a new aircraft that could provide the customer with a purpose-built trainer and training system. Finding a partner made sense and it turned out that Boeing and Saab are great partners”.

Boeing revealed its partnership with Saab in December 2013. At the time President and CEO of Saab, Hakan Buske said: “Saab has already invested in the development of the T-X advanced trainer aircraft. If Saab and Boeing win, Saab will carry that commitment a step forward into manufacturing and production in the United States”.

Ted Torgerson said Boeing entered the competition with a new jet trainer aircraft and training system designed specifically to meet the US Air Force trainer requirements. He said: “Over time the requirements evolved. We rapidly built a cohesive team with Saab and our other supply base partners; that is not always easy to do. Plus, we did this quickly and created a close team to develop, manufacture, integrate, test and fly an aircraft within 36 months”.

Design features

Boeing’s BTX-1 model is designed to look, feel and perform like a fighter aircraft featuring a stable and maneuverable airframe with a twin-tail design that give improved stability, excellent control, and inherent speed break functionality. Boeing is reluctant to release details of its BTX-1 specifications but did confirm to AIR International that the aircraft has a dry wing, with what Boeing terms “growth options”, a proven landing gear design, and a landing speed slower than a T-38 for improved safety. Boeing said BTX-1 has undergone a rigorous Federal Aviation Administration ready-to-fly examination process to confirm the company’s ‘safe to fly’ protocols and requirements.

MILITARY BOEING BTX-1

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Both BTX-1 aircraft flew together for the first time on April 27, 2017.
Boeing

Discussing the BTX-1 design, Torgerson said: “We designed as many elements and features as we could to make sure our T-X is a very safe aircraft to fly. It has twin tails for improved stability, a proven landing gear system, the GE F404-GE-402 engine with an afterburner which is helpful when you need extra power. Also, our T-X has a large wing and leading-edge root extension to improve turn rate and agility compared to the T-38. All of these elements and many others improve the safety of our T-X and make it easy and safe to fly for student pilots and instructors alike”.

Torgerson also explained how the BTX-1 was developed and designed around the cockpit. He said: “We talked with many current and former T-38 instructors and determined the aircraft presents the instructor with a challenge to see over the student’s head. Our T-X aircraft has an elevated instructors station. We call this stadium seating—so the instructor can see over the student even when they are on a steep glide path on approach. The leading-edge root extension starts aft of the instructor cockpit so the view over the side is good. The cockpits are designed with suffcient space to accommodate all body sizes so that women and men can safely, and comfortably fly our trainer”.

Torgerson highlighted that for a purposebuilt trainer, the cockpit is the aircraft’s payload and where the training happens. He said: “We have made sure we have a state-of-the-art cockpit with capacity for growth including glass displays and intuitive features. The current generation of students brought up with smart phones tend not to read instructions but push buttons and go. So, we have created icons on the displays that interface with the aircraft and how to fly it, ones that operate like apps on your smart phone. We also have hands on throttle and stick [HOTAS] controls such that the student or the instructor can use both the HOTAS controls and the displays to command the aircraft what to do. The forward cockpit is also fitted with a head-up display”.

Boeing’s first BTX-1, registered N381TX (c/n 00001), made its maiden flight on December 20, 2016. Following the flight, test pilot Steve Schmidt said: “The airplane performed extremely well, but what really stood out was how responsive, stable and predictable the aircraft was.”

Ground-based systems

Torgerson highlighted the US Air Force’s interest in downloading part of its training syllabus with the new T-X system. He said: “Some components of pilot training currently performed by students flying the T-38, the Air Force wants to download to ground-based systems — such as formation flying, aerial refuelling training, line ahead flying, simulated air combat, missile firing, targeting using a pod and bomb dropping. Air Education and Training Command is still evaluating how the [download] process will evolve to perform tasks with ground-based systems to improve training, and reduce the use of advanced fighters and bombers so therefore costs”.

Torgerson added: “Our advanced groundbased training system is housed in our building at the St Louis facility as is our systems integration laboratory, iron birds and all of the other equipment we need to support the Boeing T-X programme”.

The US Air Force has a stringent requirement for high reliability, easy support and quick turnaround. Air Education and Training Command requires the capability to fly at least four sorties per day with the new advanced trainer. Torgerson said: “We needed to build a jet that could fly many times a day with easy maintenance. Our aircraft, trainer and systems designers were all located together and were all involved in the system trade studies. As a result, we have included many features that support high reliability and easy maintenance including a high wing design, easy to reach panels to access avionic and other major systems. You don’t have to turn a screw to open an access panel, you just push a button. We can remove and replace the F404 engine in a short time. We’ve already shown the reliability of the aircraft and can quickly turn a jet between flights to fulfil the Air Force requirements, thus we are proud of our progress to date”.

BOEING BTX-1 MILITARY

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BTX-1 N381TX on an early test flight from St Louis- Lambert Field.
Boeing

“We designed as many elements and features as we could to make sure our T-X is a very safe aircraft to fly.”

Ted Torgerson, Boeing’s T-X programme manager

Describing the BTX-1 as a fighter aircraft that’s a trainer, Torgerson said the highperformance aircraft has been tested across its flight envelope and has demonstrated excellent capabilities — including high angle of attack, manoeuvring, synthetic training and performance equivalent to a fighter aircraft”. The latter is important for the Air Force given its concept for using T-X aircraft assigned to fighter training squadrons tasked to fly dedicated adversary missions that amounts to tens of thousands of hours of annual flight time.

Torgerson said the two BTX-1 aircraft flying from the St Louis facility are “the most identical aircraft Boeing has ever built, and fly exactly alike and meet all of the goals the company had hoped for”. This assertion is based on the collective experience of the test pilots from both Boeing and Saab who have flown the aircraft to date.

Torgerson confirmed the aircraft’s design is ready for final development and could enter flight testing a few months after a contract is signed but was not prepared to disclose how many flight hours have been accumulated, citing that T-X is not a contest. However, he did acknowledge the team has been flying the type since December 21, 2016 and conducting a fairly regular flight schedule since that time.

Boeing’s T-X frontman also highlighted the advantages provided by use of the latest tooling technology and manufacturing techniques “not available to an upgrade of an older, existing design aircraft” a quip at the competing contenders; the Lockheed Martin T-50 and Leonardo DRS T-100 based on the M-346.

Torgerson added: “Requirements for the training system’s ground-based systems visual acuity are also very stringent. The level of visual acuity provided by our system is such that you can see things as a pilot really sees such as leaves on trees and other fine details, an aspect that meets or exceeds the customer’s requirements. Our suite of training devices ranges from part task trainers, desktop PCs with throttle and stick controls, to a 360° dome within which the seat does not move, but provides motion cues to support a real flying experience; the pilot’s G suit even inflates when you pull G.”

Boeing’s Michael Pavloff, a former T-38 instructor reckons the ground-based training system is as realistic as possible. He said: “When a student flies the simulator it’s just like flying in the airplane. We’ve also replicated a lot of the tasks currently only available in a fighter aircraft and not possible in a T-38”.

Ted Torgerson added: “From a synthetic perspective our training capabilities embedded in the aircraft, and the connected systems are highly accurate and will allow engagements involving multiple players, feature a selection of training modes of operation, and send-off downloads for post-flight analysis. The new BTX-1 trainer can perform many tasks more effectively and far cheaper”.

Torgerson said: “If selected the Boeing-Saab T-X systems will provide a brand-new aircraft as part of a total training system designed for future growth.”

Should the BTX-1 win the US Air Force competition, the Boeing-Saab team has announced the St Louis plant will be used for the final assembly production line with a projected estimate of 1,800 new jobs at full rate production.

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Boeing’s first BTX-1 takes off from the runway at St Louis-Lambert Field in full afterburner. The GE F404-GE-402 engine has a thrust class rating of 17,700 to 18,100lb.
Boeing