Officially known as Instrumented Production Aircraft, but known more widely in the industry by their abbreviation IPA, these are crucial pillars in the continuing evolution of Typhoon.
Few people know them better than BAE Systems' Head of Air Flying, Steve Formoso, who has clocked up hundreds of flying hours experience in the cockpit of several different UK IPAs. Here he explains more about the fleet and what makes them so integral to keeping Typhoon as the backbone of global combat air power.
What and where is the IPA fleet?
The respective Eurofighter industry partners have test centres in the UK at BAE Systems, Germany through Airbus Germany, Spain with Airbus Spain, and in Italy with Leonardo and there are several IPAs based at each centre.
The IPAs allow each team to carry out development flying where new capabilities are tested and evolved and they are configured as close to the customer’s production aircraft as possible.
But the work they do does not stay within that one nation, it is shared among the Eurofighter partners, so we are all benefitting from our collective experience and expertise rather than working on our own.
What is the purpose of an IPA?
They’re sometimes described as flying testbeds but there’s far more to it than that. The clue’s in the name: Instrumented Production Aircraft. Each aircraft is equipped with an array of flight test equipment allowing every aspect, from take-off to touch down and everything in between, to be recorded. All the data which comes off the aircraft is captured, from a simple button press, through to how a particular sensor is working at any point in time. It’s detail-rich monitoring that is tailored for specific tasks.
Similar to Formula One cars, IPA aircraft are equipped with advanced telemetry capabilities. This allows them to stream real-time data points from the aircraft to the ground team, providing them with a comprehensive view of what is happening during a flight. This enables the team to closely monitor and analyse every aspect of the flight as it happens.
The availability of real-time data enables the test team to make crucial decisions and implement changes during flight trials. This is particularly useful in projects like Flight Control System trials and trials where you are working with air-to-air refuelling tankers because the test team on the ground can see things that a pilot simply can’t see in the cockpit. The telemetry team can scrutinise the in-flight performance of individual valves, fuel pressures and fuel quantities in fine detail. Such a comprehensive and continuous stream of information between the telemetry crew and the test pilot is one of the reasons why the IPAs are invaluable.
Before each test flight much of the early development activity takes place on the ground on test ‘rigs’. Then during an IPA flight the test team are attempting to validate the rig findings in the real world environment. Obviously, there is no real way to simulate a weapon firing — you have to do that for real.
Do the IPA aircraft look like other Typhoons?
On the outside they look like other aircraft, but each can be easily equipped with high speed digital cameras in pods which are there to capture different aspects of a test. There are also chequered markings on the aircraft and any weapons they may be testing too. These aren’t there for aesthetic purposes; they are carefully positioned and allow the team to calibrate exactly how the aircraft and missile behaves during a firing.
Everything on the aircraft is about data gathering. When a weapon is fired there is somebody alongside at a safe position in a chase aircraft filming the event. The missile itself also has telemetry too, meaning it is sending information back to a ground station and from the expert engineering teams at places like BAE Systems in Warton, Lancashire can take that data and work with it to make Typhoon even more capable.
The cockpit is pretty much the same as the production aircraft, but it has an extra set of controls down the right hand side where we can control all of the flight test instrumentation. All the IPA aircraft are reconfigurable so they can be used for the majority of different trials.
What kind of projects do they work on?
Well take IPA6 for example. It has completed more than 700 flights and clock up more than 1,000 flying hours — it is one of the work horses of the development fleet. It has been used for most of Typhoon’s avionics upgrades. It has also been used during trials on the new Striker II helmet which we have flown in Typhoon, as air-to-air refuelling testing.
IPA6 was the first Typhoon to jettison and later fire the Brimstone 2 missile. When the missiles were fired, an incredible amount of information was captured – from the aircraft and the missile itself. And there was also video from both IPA6 and the chase aircraft. The telemetry team was also able to see exactly how the missiles behaved. The team compared how it actually performed, against how it had been predicted it should.
While the Brimstone missile was being fired, other parts of the aircraft were instrumented too. It was about maximising the amount of data gathering from that one single event —and getting as much information off the aircraft as possible. The team had one chance.
How do you prepare for a first missile firing?
The team started the job by doing a series of computer models. It wanted to look at what should happen when the missiles were fired. The model was studied and assessed until everyone was confident it would work. The team then drew a flight envelope, which consists of the maximum speeds, heights, and G forces, it was happy to test at. Obviously, safety is paramount in this kind of endeavour. Later, after gaining confidence with each successful IPA flight, the team moved towards the edges of the envelope.
The test isn’t simply about the weapon release, it’s about checking key things like the mission systems and the avionics, and ensuring the pilot can control the missile.
Prior to testing the ‘real’ thing there are lots of simulated firings with dummy missiles. The team is even able to modify the way the flight control system operates in an IPA so that it can get the most out of the testing.
Is 1,000 flying hours a lot for a test aircraft?
Yes, because of the specialised nature of the job, an IPA typically spend a lot of time on the ground getting prepared for trials. Each new project might be completely different from previous one and that means a wholly different configuration.
IPA6, which has flown over 1,000 hours is a real work horse in IPA terms. I have flown it 118 and I actually flew it first when I was in the RAF and I have now been with BAE Systems for ten years - so that tells you how much value it has made to helping enhance Typhoon's capabilities.
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