MADE IN ENGLAND
In the second of a three-part series on aircraft designed and produced by BAE Systems, Mark Ayton provides an update on the venerable Hawk trainer
BAE SYSTEMS HAWK MILITARY
When AIR International visited Team Hawk at BAE Systems’ Warton facility the company had completed work to integrate new technologies and systems into its Advanced Hawk technology demonstrator.
Hawk ZJ951 is a development aircraft, with a standard Hawk T2 mission computer and mission system, but is now fitted with a unique package of kit all more advanced than any earlier Hawk variant.
During a programme of flight trials with ZJ951, Team Hawk is proving a yet-tobe defined future development path for Hawk and de-risking a potential upgrade package for existing customers; none of the technologies however, represent finished products.
Hawk concepts
As part of the visit to Warton, AIR International had the opportunity to visit the Training and Simulation Integration Facility (TSIF); £2.3 million worth of digital and virtual nirvana. Pretty cool it is too.
Some of the technologies demonstrated to AIR International have their roots in ongoing work being undertaken in the TSIF in its technology development efforts.
One such system within the TSIF is a twinseat development simulator. At the time of AIR International’s visit the simulator was fitted out with a future cockpit configuration featuring a large area display in the front cockpit; one of a number of configurations possible.
Team TSIF, working with Team Hawk, have put a lot of time and effort into how the company moves from the current standard three multifunction display Hawk cockpit to a large area display, akin to the panoramic cockpit display fitted in the American F-35 Lightning II fighter. Much work has already been completed testing commercial off the shelf technologies in hardware-in-the-loop test rigs at Warton. The big challenges of this essential work were ensuring the correct drivers were loaded on the aircraft’s mission computer to ensure the large area display runs and functions Work being undertaken in the simulator is helping determine the display’s necessary appearance, how the aircraft is controlled using the large area display, the requirements of the display and its functionality, and how to optimise the screen for training pilots; the primary role of the Hawk.
This development work has been funded by BAE Systems and also includes some neat aerodynamic improvements to the Hawk’s wing.
Team Hawk is well down its development road right now, so much so that if either an existing or potential Hawk customer wants an F-35 style of cockpit for its Hawks or new Hawks, BAE Systems reckons it’s a relatively manageable step to move from flight test and qualification to production.
The initiative is a demonstration of the company’s intent to push the technologies and design features forward to prove the Hawk-based flying training system has a new guise for both current and a future variant. Team Hawk says any new variant will most likely be ‘a son of Hawk’, for which there are currently different options open for potential development.
BAE Systems Hawk Business Development Director, Phil Hodge said: “The likelihood is we would brand it [a future variant] in another way. That isn’t absolutely cast in stone, but there’s fantastic lineage and heritage with the name Hawk, qualities that no other company in the business of producing training aircraft can follow. Competitors may well say Hawk is a 1970s designed aeroplane, but the current standard Hawk was designed in the early 2000s. Just consider the RAF’s Hawk T2, it’s a totally different aircraft to the original Hawk T1. The company will have to take a long hard look at whatever option comes along, whether it is branded Hawk, or whether it is branded and named something else. For every upside, the lineage, the heritage and everything we’re proud of, the downside is that the Hawk name and brand has been around for a long time so maybe the market is ready for something else.”
BAE Systems is confident of its viable development path for the current Hawk T2 aircraft and mission system for the next two decades. But Phil Hodge and his team are not complacent and realise nothing lasts for ever, hence its work on future options in parallel with a development path for the current platform.
Recent Hawk customers like India, Oman and Saudi Arabia will operate the jet until the late 2030s, and the type’s relevance in RAF service will continue given the service’s training requirement for Typhoon, F-35 and the first born son of Team Tempest.
To meet lead-in fighter training requirements for such machines, pilot training will be more reliant on sensor simulation and cockpit layout, aspects that are easy to configure on the software-driven Hawk in a manner that meets today’s and tomorrow’s training requirements.
But is there a need for BAE Systems to develop a new fast jet trainer aircraft to maintain parity with existing competitors?
Answering the question, Phil Hodges said: “We’re already at parity with existing competitors; Hawk currently delivers trained pilots for Typhoon and F-35, which it will continue to do. Hawk has a robust set of through life costs. It’s very reliable, very maintainable and remains a very relevant platform for the current thread of customers, so, we don’t need to do anything with the current platform to maintain parity, but we will need to develop aspects like enhanced sensor simulation, and a large area display to match competitors in the near term. The milliondollar question is, what do you need to do in the long term and where do you need to be?
That’s why we’re working on options.”
According to Aircrew Training Specialist, John Hurrell the aspects outlined by Phil can be taken at two levels. He said: “The concept of integrating new technologies and systems into the Advanced Hawk technology demonstrator was to take the best of everything BAE Systems had developed on previous Hawk derivatives, and build it all on to one aeroplane, give it a bit more air-toground capability, give it enhanced sensor simulation capability, a large area display, and smart weapon capability.
“Then take the high risk elements, those that require flight testing, such as the wing and large area display which require a lot of change to the mission computers, and propose them as a future concept that potential customers might want. Think of them as upgradable aspects and part of a proof of concepts of a potential whole solution and a technology demonstrator.”
Development simulator
Team TSIF’s twin-seat development simulator was designed in collaboration with Williams Advanced Engineering of F1 fame.
According to BAE Systems, the simulator is flexible and can be configured to replicate any customer’s aeroplane and resemble a range of training and fast jet cockpit environments including Hawk. It allows users to trial the latest in human machine interfaces.
In addition to the simulator, BAE Systems uses the facility to demonstrate what future capabilities may look like. How? By using an augmented reality environment which utilises virtual and augmented reality technology to create a fully immersive 3D environment for engineers and pilots to enhance their aircraft maintenance and training skills in complex environments.
Another TSIF system is a classroom of the future featuring wall-to-wall interactive displays that allows trainees to virtually tour an aircraft utilising a number of synthetic training aids designed to enhance the learning experience, reduce the reliance on expensive physical tools and increase the rate of learning.
And if those three super cool (and they are super cool) capabilities were not enough, the TSIF also has a networked synthetic environment with a suite of highspeed desktop simulators for a range of aircraft types including Hawk. Connected via a dedicated engineering network, the desktop sims allow pilots and engineers to train together in a synthetic environment and simulate a range of realistic mission training scenarios involving multiple aircraft types.
The development simulator in use during AIR International’s visit has now been replaced by a new one. The new machine, like the original, is used to develop software, capabilities and concepts, and has nothing to do with Hawk per se, although capabilities like gesture controls, and eye tracking, under development with the simulator could likely be used on future Hawk training options.
So what considerations does Team TSIF give when developing a technology for potential use in future pilot training? According to John Hurrell, any technology which makes it into the cockpit must provide utility and reduce the pilot’s workload. He said: “Today we’ve got information overload in the cockpit. The challenge when you’re learning is not; do I have the information? It’s how to channel the information. How do I use it? How do I fuse it? What do I use? What do I ignore?
“In my view, every aircraft manufacturer must focus on keeping the pilot’s eyes out of the cockpit as much as possible. We have developed cockpits with multifunction displays with different levels of information, menus and activity that keep a pilot’s eyes in the cockpit more than is ideal. You just don’t have time in fast jets to do that. You can’t afford to do it and you can’t afford for your student to do it. By using a large area display we are trying to get away from that concept. Information needs to be easy and quick to access reliably.”
Team TSIF is working on new concepts for the aft cockpit, ones that no one at BAE Systems is prepared to discuss right now. Some of the concepts may find their way into Hawk, but they are not Hawk specific.
Large area display
Demonstrating the functionality of the large area screen installed in the development simulator’s front cockpit, John Hurrell said installation of a large area display makes most current controls and selections in the cockpit redundant. Very nearly every system is accessed on the display except for landing gear, a flap lever and a throttle.
The display comprises two screens with dual redundant power supplies which can be configured to everything from the basic instruments needed for the early stages of pilot training to full advanced tactical displays in high definition. John Hurrell rates large area displays and reckons the reasons for using them for pilot training and operational flying are compelling. He said: “It’s cheaper, lighter, high definition, and easier to configure, and takes up less space in the cockpit. What is there not to like? Importantly it’s an easy cockpit to learn without spending hours on desktop trainers and in simulators and it avoids the pilot having to look down into the cockpit.”
Team TSIF opted to use IR beam screens and not regular touch screens. Why? Because of the simplicity of breaking the IR beam which is very functional in situations such as when the pilot is looking over his or her shoulder. Think about tapping a smart phone to invoke a command. Then think about how many times that action does not work properly. Then think about such touch screen dysfunctionality if you were a pilot looking over your shoulder in a high g manoeuvre, and you’ll appreciate the difficulty.
The display uses portals, effectively a separate display within the large area display.
Each portal is scalable to the screen’s full size, each one capable of displaying any information, with all information moveable between portals.
Data is entered using portals because there is no permanent data entry panel in the cockpit. One such example is a radio frequency. Once the frequency is entered, the pilot touches the portal to remove the data entry panel from the display.
Information can also be dropped-down on to the display by clicking a tell-back button.
For example, information about the engine can be dropped down on the display by touching a tell-back. Another touch gets rid of the information. This one press, one function ability is an example of removing the need for the pilot to look down into the cockpit and select different menus.
Another concept under development by Team TSIF to minimise time spent looking head down into the cockpit particularly in high threat environments trying to decide what you want on what screen is one that merges tactical displays. Team TSIF’s display tool enables the pilot to fade in a tactical display simply by touching the screen, and then swiping the screen to remove the information from the screen when no longer required.
Explaining the concept, Phil Hodge said: “The team is starting to prove a way of getting information to the pilot and a way for him or her to quickly and accurately interact with the aircraft in order to remove the time required to work through menus. We think, this is one of the ways of doing that.”
Slats and tips
Earlier in this feature, we mentioned aerodynamic improvements to the Hawk’s wing. These have been designed and installed on development aircraft ZJ951 to increase its performance in some flight regimes.
This development may well appeal to some Hawk customers, particularly those with a preference for a greater level of operational performance, more specifically better up and away, and better bring back.
For other customers who operate Hawk aircraft in a pure training role, aerodynamic improvements to the wing will also be relevant particularly for pilots undergoing lead in fighter training because of the ability of the modified aircraft to fly at greater angles of attack dubbed alpha.
John Hurrell reckons that in certain regimes the modified aircraft turns with performance close to an F-16, which is quite a claim. He said: “We’ve taken the aircraft to very high alphas and it has not departed [controlled flight] and it has not stalled. That’s very beneficial when teaching a student pilot how to fly high and slow to get behind an adversary and take a missile shot. If you can achieve that, then he or she will probably win the fight. That’s what you’re trying to do in close combat in a fighter, so that’s why we want the high alpha capability.”
To prove the concept Team Hawk has modified the standard wings of Advanced Hawk ZJ951 in two ways; extended the wing span and added large fixed leading edge slats. With a 9.5-inch (240mm) long extension to each wing, and full length slats, the aircraft’s total wing area is increased by 9%.
Team Hawk’s aim for future production wings is to have a fully automated slat and slot to save the need for the pilot fiddling around trying to decide the setting.
Installation of a fully automated slat was not feasible given the short timeline available in the development stage; less than three months, so the solution was to use a fixed slat set at one of three positions (zero, six, and 16-degrees) between flights.
Each slat comprises the slat (the aerodynamic surface that allows the wing to operate at higher angle of attack), and a slot between the slat and the wing. The arrangement was such that the slot only appeared at the higher 16-degree slat angle where it is required for the higher angles of attack at lower speeds.
Flight testing started with the fixed slat in the zero-degree position to provide a datum for the development of flying. Testing then progressed to the six-degree high-speed position, one that gives a better high turn rate, high sustained turn rates, and high instantaneous turn rates.
Discussing the flight testing, John Hurrell said: “We can’t configure the slat in the air [because it is fixed], for real you will and we’ve flown several sorties in each position all the way out to the 16-degree position, the high lift, low speed configuration.”
AIR International asked John Hurrell how the fixed slat affect ed landing? He said: “It has an effect. We evaluated speed and configuration for each setting in the simulator to check it could be safely flown and the envelope is safe, aspects that must be taken into account with a slat that can’t be reconfigured in flight. Obviously critical speeds are different, take off runs are different, brake limiting speeds are all different, but all sit within the envelope of course.
The aircraft’s fin is also extended by about nine inches than the original configuration. This was done to provide sufficient directional stability to its original design requirement when flying at high alphas.
Finally, the aircraft is fitted with a stability augmentation system to provide some active damping. At high alpha and low speed, the aircraft, even with a larger fin surface area requires co-ordinating rudder in rolling manoeuvres. The stability augmentation system automatically feeds control inputs to provide this co-ordination and in doing so avoids departure from controlled flight. It was fitted to ZJ951 just for the trial and proved successful.
The test team had to ensure the loads and twisting motions induced on the reconfigured wings and fin were within the original design limits. Compliance was verified by 230 strain gauges fitted around the aircraft all linked to the telemetry system and downloaded for constant monitoring during each test flight. According to John Hurrell no issues were encountered during the flight test programme.
Cockpit
Looking into ZJ951’s forward cockpit John Hurrell pointed out the devices installed as part of the technology trials.
First off is a new head-up display dubbed LiteHUD (a smaller model than the version fitted in the RAF’s Hawk T2) comprising a single combined glass with a wider raster/ angle of view.
Second, and most notable, is the large area display, which has allowed the original cockpit configuration to be cleaned up, with just the original central warning panel remaining in place; this too might eventually move to the large area display.
John Hurrell reckons the demonstrator cockpit is pretty easy to use. He said: “Pilots will transition easily to the new cockpit without hours of briefing and extensive use of desktop trainers and simulation to do so. There is no aspect [of ZJ951’s demonstrator configuration] that has surprised us, due to the wind tunnel results and aero modelling obtained before we started the programme. We’ve flown the aircraft to high alphas. It’s still flyable. It has not stalled, it’s never departed. It seems very stable and we’re very pleased with its performance.” AI
