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Old article but interesting nonetheless:
Two weeks ago at the Air Force Association convention, Northrop Grumman briefed media on the Distributed Aperture System (DAS) that it is developing for the F-35 Joint Strike Fighter. Subsystem briefs aren't always revealing, but this was different.
As this story in DTI (p40) explains, DAS comprises six fixed, wide-angle infrared cameras that constantly image the entire sphere around the F-35. It's been publicized in the past for its ability to allow the pilot to "see through the floor" in a vertical landing, and one of its functions is to provide imagery to the VSI helmet-mounted display. Another is missile warning. But one of the DAS' most interesting capabilities is that it can constantly track every aircraft in the sky, out to its maximum range - which varies but, absent clouds, covers the within-visual-range envelope.
DAS has two vital attributes in this respect: it stares, never looking away from any target, and it has optical accuracy, with megapixel-class resolution. (Northrop Grumman didn't say "megapixel", but one of their suppliers did. Bad supplier! The naughty spot for you!) This means that once a target is ID'd, it stays ID'd, and the pilot can see what every aircraft around him is doing.
Moreover, DAS is expected to track with enough accuracy and tenacity to permit a safe high-off-boresight, lock-on-after-launch (LOAL) missile shot with any datalink-equipped missile. Indeed, Northrop Grumman's DAS business development leader, Pete Bartos - who was part of the initial USAF JSF requirements team - says that this was basic to the F-35 design and the reason that it did not need maneuverability similar to the F-22. Rather than entering a turning fight at the merge, the F-35 barrels through and takes an over-the-shoulder defensive shot. As a Northrop Grumman video puts it, "maneuvering is irrelevant".
What this says about the F-35 is that the 1995 statement of its godfather, George Muellner, still stands: it is 70 per cent air-to-ground and 30 per cent air to air. Consider the USAF, by far the largest customer, in 1995. It was expecting to get 442 F-22s, which would dominate any foreseen air threat (a major regional power) for decades. It was four years after Desert Storm, where the F-117 had been the star, combining stealth and precision attack into an overwhelming force multiplier.
Looking back, the USAF was clearly seeking something that would do the F-117 job while remedying its limitations. The F-117 was a clear-night system, unable to bomb in adverse weather or survive in daylight, and could not hit all the targets covered by other strike aircraft.
The JSF requirement was built around an F-117's internal weapon load. It added a radar and GPS-guided weapons for all-weather attack. It added situational awareness (that is, an EW system capable of detecting, identifying and avoiding pop-up threats) and AAMs for self-defense, for daytime survivability. Finally, it added external pylons for the "day two" missions and the entire target set tackled by F-16s.
All this had to fit inside the tightest limitation imposed by the joint-service JSF concept, which was size: the Marines and the UK wanted (but didn't get) an aircraft no bigger than an F/A-18C.
Within those limits, the JSF could not be designed for the supersonic cruise and maneuverability that had been included in the F-22. Moreover, it was the first USAF requirement written after the end of the Cold War, and the rude shock of realizing just how dangerous the Vympel R-73 and associated helmet-mounted sight would be in close combat.
Rather than attempting to play a game that might be mutual suicide, the JSF requirement authors stressed stealth, situational awareness and LOAL. If the fight does get to the merge, the best thing to do in an F-35 is to accelerate through it, put the adversary in the rear sector and take an over-the-shoulder shot.
Of course, the use of 360-degree weapons on a fighter has an illustrious precedent...
...about which the less said the better. If the Germans had had an expression for "clubbed like baby seals" in 1940, the Luftwaffe would have used it.
The other first-level observation about the JSF self-defense strategy is that - at service entry - the jet won't carry (internally) a missile that is very suited to the job. The AIM-120 can in theory be vectored in any direction, although it generally receives updates via the radar, which cannot update the missile outside its field-of-regard, and the weapon's design emphasizes range and speed rather than agility. The F-35 can carry the AIM-9X Block 2 or ASRAAM, but only on external pylons. And even with a more-stealthy pylon design - discussed earlier this year - that's a serious compromise.
Eventually, the F-35 may get an internal, LOAL AIM-9X capability - because that's what it really needs to take advantage of DAS.
Source: JSF - "Maneuvering is Irrelevant"
Two weeks ago at the Air Force Association convention, Northrop Grumman briefed media on the Distributed Aperture System (DAS) that it is developing for the F-35 Joint Strike Fighter. Subsystem briefs aren't always revealing, but this was different.
As this story in DTI (p40) explains, DAS comprises six fixed, wide-angle infrared cameras that constantly image the entire sphere around the F-35. It's been publicized in the past for its ability to allow the pilot to "see through the floor" in a vertical landing, and one of its functions is to provide imagery to the VSI helmet-mounted display. Another is missile warning. But one of the DAS' most interesting capabilities is that it can constantly track every aircraft in the sky, out to its maximum range - which varies but, absent clouds, covers the within-visual-range envelope.
DAS has two vital attributes in this respect: it stares, never looking away from any target, and it has optical accuracy, with megapixel-class resolution. (Northrop Grumman didn't say "megapixel", but one of their suppliers did. Bad supplier! The naughty spot for you!) This means that once a target is ID'd, it stays ID'd, and the pilot can see what every aircraft around him is doing.
Moreover, DAS is expected to track with enough accuracy and tenacity to permit a safe high-off-boresight, lock-on-after-launch (LOAL) missile shot with any datalink-equipped missile. Indeed, Northrop Grumman's DAS business development leader, Pete Bartos - who was part of the initial USAF JSF requirements team - says that this was basic to the F-35 design and the reason that it did not need maneuverability similar to the F-22. Rather than entering a turning fight at the merge, the F-35 barrels through and takes an over-the-shoulder defensive shot. As a Northrop Grumman video puts it, "maneuvering is irrelevant".
What this says about the F-35 is that the 1995 statement of its godfather, George Muellner, still stands: it is 70 per cent air-to-ground and 30 per cent air to air. Consider the USAF, by far the largest customer, in 1995. It was expecting to get 442 F-22s, which would dominate any foreseen air threat (a major regional power) for decades. It was four years after Desert Storm, where the F-117 had been the star, combining stealth and precision attack into an overwhelming force multiplier.
Looking back, the USAF was clearly seeking something that would do the F-117 job while remedying its limitations. The F-117 was a clear-night system, unable to bomb in adverse weather or survive in daylight, and could not hit all the targets covered by other strike aircraft.
The JSF requirement was built around an F-117's internal weapon load. It added a radar and GPS-guided weapons for all-weather attack. It added situational awareness (that is, an EW system capable of detecting, identifying and avoiding pop-up threats) and AAMs for self-defense, for daytime survivability. Finally, it added external pylons for the "day two" missions and the entire target set tackled by F-16s.
All this had to fit inside the tightest limitation imposed by the joint-service JSF concept, which was size: the Marines and the UK wanted (but didn't get) an aircraft no bigger than an F/A-18C.
Within those limits, the JSF could not be designed for the supersonic cruise and maneuverability that had been included in the F-22. Moreover, it was the first USAF requirement written after the end of the Cold War, and the rude shock of realizing just how dangerous the Vympel R-73 and associated helmet-mounted sight would be in close combat.
Rather than attempting to play a game that might be mutual suicide, the JSF requirement authors stressed stealth, situational awareness and LOAL. If the fight does get to the merge, the best thing to do in an F-35 is to accelerate through it, put the adversary in the rear sector and take an over-the-shoulder shot.
Of course, the use of 360-degree weapons on a fighter has an illustrious precedent...
...about which the less said the better. If the Germans had had an expression for "clubbed like baby seals" in 1940, the Luftwaffe would have used it.
The other first-level observation about the JSF self-defense strategy is that - at service entry - the jet won't carry (internally) a missile that is very suited to the job. The AIM-120 can in theory be vectored in any direction, although it generally receives updates via the radar, which cannot update the missile outside its field-of-regard, and the weapon's design emphasizes range and speed rather than agility. The F-35 can carry the AIM-9X Block 2 or ASRAAM, but only on external pylons. And even with a more-stealthy pylon design - discussed earlier this year - that's a serious compromise.
Eventually, the F-35 may get an internal, LOAL AIM-9X capability - because that's what it really needs to take advantage of DAS.
Source: JSF - "Maneuvering is Irrelevant"
