Flying SUPERSONIC with NO Afterburner | Why SUPERCRUISE is so Important?

so so I bet you’re wondering what all these planes have in common super cruise is a feature that most modern fighters have it is considered a badge of performance and it is like the membership of an exclusive club so why is it important as usual the explanation is not exactly what you would expect so stay till the end because what we’re going to discuss here is not easily found anywhere else apparently the term supercruise was coined for the first time in the late 60s and early 70s by the group of united states air force officers known as the Fighter Mafia they refer to super cruise as the ability for a plane to accelerate and keep flying at supersonic speed without using the afterburner colonel John Boyd who inspired the Fighter Mafia conceived the famous E-M theory aware combat it is a subject good for various videos actually but for now it is enough to know that the theory advocated that maintaining a high level of energy kinetic and potential was the key for success in air combat the ability of keeping a constant supersonic speed was considered helpful to keep the energy high however supercruise was not a new feature the first plane to accelerate at supersonic speed without afterburner was probably a French experimental delta wing plane in the mid 50s the first production plane to achieve super cruise was the F-104 at high altitude however it is not considered to be the first super cruise plane because it could do so only in that very clean configuration with no extra fuel tanks and without using the flaps and the slats in cruise as often the F-104 used to do the feature in this case was of no military value the first plane explicitly designed to super cruise was the British BAC TSR 2 strike and reconnaissance aircraft that unfortunately was never severely built the plane was designed to supercruise at Mach 2 at high altitude and Mach 1.1 at sea level the Concorde was strictly speaking not a supercruise plane because it needed the afterburners to accelerate above Mach 1. the SR-71 was designed to cruise with the after burner on so technically it couldn’t supercruise either one may wonder why accelerating to supersonic speed is so difficult well the reason is of aerodynamic nature the behavior of fluid changes quite radically when we approach the speed of sound in the fluid in fact at transonic speed a new type of drag appears the wave drag it is nothing other than the drag associated to the shock waves the wave drag grows very quickly reaches a max at Mach 1 and then it diminishes again above Mach 1 where the nature of the flow starts changing again now if you are still here it should be clear by now that a jet may need some extra trust to overcome the wave drag and go beyond the speed of sound in the large majority of jet this is the purpose of the afterburner the afterburner is part of the fascination that we all have for jets the long streak of brilliant hot gas is always a sight to behold however the afterburner doesn’t exist for aesthetic reason it can greatly increase the trust of a turbojet over or a turbofan the principle is easy since not all the oxygen in the engine flow is used in fuel combustion if some more fuel is injected downstream the turbine and ignited it can abruptly reheat the gases and cause a violent expansion that produces extra trust what is important to understand here is that while the trust of a jet engine can be in practice roughly doubled with an afterburner it is a very inefficient way to obtain extra thrust that is the fuel consumption can be three or four times or even more the consumption without the afterburner the extra heat induces thermal loads on the engine structure the nozzle and the nearby fuselage military planes have a limit on how long the afterburner can stay on before structural problems start occurring another reason why the use of the afterburner can be problematic is that the strong heat emission and the gas plume produce a large infrared signature so in practice the less you use the afterburner the better its use should be reserved to emergency and combat situations enters the supercruise speed in combat is very important it has been like this since the dawn of air combat so it is to be expected that a feature like the supercruise is kept in high regard by the pilots the technical reasons why supercruising is important should be rather clear by now the plane can reach and maintain a supersonic speed without using the afterburner and incurring in the relative consequence please note that super cruising still requires more fuel than cruising at supersonic speed but way less than using the afterburner a rough estimate of the fuel consumption is still 25 to 30 percent higher than cruising at high subsonic speed it is also important that the plane could super cruise with a military useful payload since modern fighters carry their weapons and fuel externally their drag increases dramatically when equipped with an actual payload in general no plane can supercruise with any air-to-ground payload because they tend to be large and generate a lot of drag air-to-air weapons on the contrary may be heavy as well but they usually generate less drag even because in some cases they can be hosted in recessed station obvious exceptions are the American F-22 and the Russian SU-57 that transport all their weapons internally and almost always fly in a clean configuration with internal fuel only the actual performance of fighters is a secret but still we have enough information to understand the importance of this feature the F-22 is expected to super cruise up to Mach 1.8 and it is probably the fastest supercruiser currently in service the Rafale is known to be capable of super cruising around Mach 1.4 with a standard air-to-air weapon load and one external fuel tank the Eurofighter typhoon has a cruise speed of Mach 1.

5 with air-to-air weapons 09:12 - but no fuel tank the Gripen E/F with the upgraded engine has demonstrated a Mach 1.2 supercruise capability with an air-to-air payload and a fuel tank the information about the Russian designs is even less certain the SU-35 can probably supercruise around Mach 1.2 as well the SU-57 has been confirmed of being capable of super cruising but the speed is not known I did not mention the F-35 because contrarily to what many F-35 fanboys think the F-35 cannot super cruise comments erupting in flames in three two one all the fifth and sixth generation aircraft currently in development are being designed to be supercruisers as well and this is an obvious testament to the importance of the feature for the militaries but at the end of the day why it is so so if you think that modern air combat is going to start with the merge you’re wrong video games have a veneer of credibility but they’re different from reality actually pilots train for the merge and close combat because it may always happen but they prefer keeping an healthy distance from the enemy and fight beyond the visual range what they want to do is making full use of the weapon’s kinematic performance if you have watched my older videos about air-to-air missiles you will know that the missile range and the ability to hit the target is not expressed by a fixed number but it depends from the flight profile the altitude at which the plane and the missile are flying and crucially the energy it can muster a flight profile that chases the plane rather than anticipating it or a trajectory with many curves is very energy inefficient to shorten the useful range and reduce the ability to hit the target a lob trajectory on the contrary may be very efficient because the weapon will fly in in thin air with low drag for most of the trajectory and it will still have energy at the end of the path to maneuver and hit target aided by gravity now what do you think will be the difference if the same weapon is launched at Mach 0.8 or at Mach 1.4 in the second case it will have already a lot more energy that will add to the missile propulsion extending the range and the flight envelope this will happen not only because the speed is higher but also because the weapon will not need to go through the sound barrier under its own propulsion spending a good amount of inputs just to overcome the peak of the wave drag at transonic speed a super cruiser enters the fight already at an ideal speed to use the long range weapons a non-supercruiser will need to accelerate first using the afterburner or accept the weapons range penalty notice it will also be using the afterburner after jettisoning the fuel tanks to be ready to close combat should it happen that is it will burn a lot of fuel exactly when its fuel capacity is reduced this may severely affect the persistence in combat of the plane while the supercruiser can keep flying at the speed suitable for air combat and staying in the fight for way longer but this is not the end the faster a plane flies the more the missile need to lead the trajectory to calculate an impact point the more it will need to veer off course if the plane changes direction the more energy it will need to spend to the show speed is a defensive measure in itself not only because it allows you to run away if necessary but because makes the interception trajectories inherently more expensive in terms of energy speed depletes opponent missiles energy in general a supercruising plane will have more energy than a non-super cruising plane and this at least according to the western military doctrine is an advantage that can be used to outmaneuver the opponent the ability of keeping the supersonic speed for longer periods can be the difference between life and that so if you like this video I’m sure you will love the videos that are going to appear beside me in the meanwhile please like dislike subscribe and hit the bell so you won’t miss anything if you could consider supporting the channel on skype star Patreon that would be amazing and you will have my gratitude forever meanwhile thank you very very very much for watching and see you in the next video .