QUOTE(usman1 @ Oct 14 2004, 11:18 AM)
Q 1 what does we mean by fly by war technology(maybe i am wrong but something like that)
Q2 what does we exactly mean by BVR capability(i know it means beyond visual range but a little detail required)
Q3 How effective is the composite material in stealth
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FBW-Fly-by-wire is a technology used to make aircrafts easy to fly and sometimes also to make ustable designs flyable.
Normal aircrafts like say a MiG-21, uses direct pilot input to the stick which is fed to the control surfaces through pure hydraulics. So the aircraft behaves exactly as you control the stick. This is a negative point as sometimes, u may overstress the frame of the aircraft during high-g maneuvering.
The first FBW was developed on a test-bed F-8-II Crusader aircraft - it was an analog FBW.
The first purely digital FBW aircraft to hit the air force was the legendry F-16 Viper. It was an unstable design, meaning that it could not fly straight without constant trimming of controls. So a computer Flight Control System was developed which took inputs from various control surfaces, as well as the pilot's stick and then maneuvered the plane accordingly within its limits.
In the F-16, a few mm of stick displacement is enough to put the Viper in maximum turn rate. Its damn sensitive !!! F-117 also used an advanced FBW coz it was unstable as well.
In Mirage-2000, the FBW has a different role. Delta design is not unstable, but it has inherent flaws, like low-sustained performance, long land-takeoff distances etc.
What Dassault did was that they shifted the Centre of lift forward of the Centre of Gravity, so the Mirage became unstable as the nose always wanted to pitch up. A 100% digital FBW was developed to control the plane. With an digital FBW, u can extract the maximum out of an aircraft at particular parameteres. Mirage FBW is optimised for alpha demand below 250 kts and g-demand above it.
Some planes are neutrally stable like the F-15, but u can install FBW to make them more responsive and easier to fly. To extract the maximum out of Flanker series fighters, u can turn the FBW off with a switch and do all the wild stuff like Cobra and stuff.
Remember that while FBW makes planes easy to fly, it restricts u from taking the fighter to the hilt during combat. Dats why PAF viper drivers think of F-7 as a very potent adversary. Experienced pilots in aircrafts like MiG-21 can make a mess of any fighter. But Flanker series fighter allow u to switch the FBW off, which every aircraft does not allow.
BTW, nowdays even throttle is digitally controlled as in Su-37. U don't push or pull the throttle, but u press a switch back and forth, and it settles to neutral on its own - like a two way switch with spring.
BVR-Beyond-Visual Range Combat begins after 20-25 Kms (a little more than that). But today with NBVR missiles (Near-BVR), u can say it begins at 30-35 Kms. It mostly utilises Radar guided missiles (some which need parent aircraft's radar like AIM-7 and some which are independently guided to some extent like AIM-120). Some missiles like R-27 also feature an Infra-red guidance for BVR. The longest range missile to arm a fighter was the AIM-54 Phoenix for use against soviet bombers.
BVR missiles started in Vietnam but no actual BVR combat happened till Gulf War. The problem was IFF (Identification Friend or Foe), they could not make out enemies and allies. So they had to visually confirm which negated the BVR advantage.
Practical fighter-fighter BVR begins at 20 kms and is not likely to go beyond 60 Kms (which is an aggressive range). The reason is that a missile like AIM-120 with a 60-70 Kms range cannot hit targets at max-range. The enemy will make a wide-turn (BEAM) or turn back to evade the missile. So kill-zone BVR does not go beyond 40-50 kms, that too in case of missiles like AIM-120, R-77 and R-27. Missiles like Derby, MICA and Super-530D have even shorter kill-zones.
If u want, u can ask for specific details, coz this topic is really huge. Some people who come to know about it straight away think that it rocks and WVR is over. But only with knowledge and experience u will learn how it is implemented in Combat.
Composites-Modern Stealth fighters employ contouring for Stealthy design, not edges like in F-117. So that is not possible without composites. And it has less reflectivity when compared to titanium or alumunium. But more important factor is contouring, which makes aircraft aerodynamically good and also stealthy.
VIPER