(Luft) Lockheed Martin F-35 - Lightning II

[revan]

So, ich habe ein sehr Interessanten Artikel gesichtet das ich keinen Vorenthalten will, er gilt als das ausführlichste Öffentlich Zugängliche Papier über die F35 und die Schlussfolgerungen sind verheerend für die F35. Auch ist die Analyse bei Überfliegen nicht oberflächlich, in Vergleich zu dem was in den USA öffentlich zugänglich ist.

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Assessing Joint Strike Fighter Survivability

While the Joint Strike Fighter has some stealth capability, a modern AESA and RFS, and the unique DAS, it presents as a design which is not well balanced in overall survivability terms.

The root of the survivability problems apparent in the Joint Strike Fighter is that its stealth capabilities are strongly dependent on aspect and threat radar operating band.

If the threat is a single, isolated mobile battlefield short range point defence SAM system, the low power-aperture performance of such a weapon will provide poor detection capability against the Joint Strike Fighter in the nose and tail sectors, but much better capability in the beam aspect sectors, especially at steeper elevation angles. In such a scenario the SAM system will wait in ambush, not emitting, and then light up to snapshoot at the Joint Strike Fighter.

The pilot’s best play is then to point the nose at the SAM system to cause the search and engagement radars, likely operating in the S-band and X-band respectively, to lose lock on the Joint Strike Fighter, while denying reacquisition by the SAM system’s adjunct thermal imaging tracker by shielding the exhaust nozzle. As such SAMs are most often command link guided, the loss of the engagement radar track will likely cause the missiles to lose guidance. The scenario where this play will fail is where the SAM system has an adjunct thermal imaging tracker with sufficient sensitivity, weather conditions permitting, to maintain a solid track on the aircraft.

If the SAMs are infrared terminal homing designs, then this strategy may be less effective if the missile seekers have acquired the Joint Strike Fighter airframe. The current defensive package includes flares which will be effective against legacy seekers, especially single colour designs. If the SAMs are equipped with imaging focal plane array seekers, now becoming very common in air to air missile seekers, flares may be completely ineffective. Literature on the Joint Strike Fighter defensive suite makes no mention of provisions for a directed infrared countermeasure system, and packaging such would present difficulties in the densely packed Joint Strike Fighter design.

If the threat is a single, isolated long range area defence SAM system, the high power-aperture performance of such a weapon will provide poor detection capability against the Joint Strike Fighter in the nose sector, but much better detection capability in the tail and the beam aspect sectors. Again, in such a scenario the SAM system will wait in ambush, not emitting, and then light up to shoot at the Joint Strike Fighter.

Again, the pilot’s best play is then to point the nose at the SAM system to cause the engagement radar, likely operating in the X-band, to lose lock on the Joint Strike Fighter. Whether the SAM system can then maintain a track on the Joint Strike Fighter will depend primarily on the operating bands of its search radars, the geographical deployment of these relative to the engagement radar, and whether these radars have sufficient angular accuracy to guide the SAM round close enough to the Joint Strike Fighter for its seeker to lock on and reliably home in.

The best case scenario for the Joint Strike Fighter is where the SAM system search radars are operating in the S-band or even X-band, and are collocated with the engagement radar. As a result of these conditions, pointing the nose at the engagement radar will likely cause all radars in the SAM system to lose track of the aircraft and the missile shot is defeated, providing the pilot reacts well before the missile seekers can gain lock.

This technique will be much less effective in conditions where the angular relationship between the Joint Strike Fighter, the engagement radar, and the search radars, allows the SAM system to gain visibility of the Joint Strike Fighter from angles well off the nose with a high power aperture search radar accurate enough to produce midcourse guidance updates for a SAM round in flight. Under these conditions the Joint Strike Fighter is “pincered” as its stealth (VLO) capability is confined to a relatively narrow sector and it cannot “make itself invisible” to both threat radars at the same time. Under these conditions a conventional fighter would fall back on its omnidirectional ECM suite and attempt to jam the search and engagement radars, missile uplinks, and missile seekers, or use a towed decoy to seduce the missile seeker.

If, and only if, the threat radars operate within the band coverage of the Joint Strike Fighter’s APG-81 AESA does jamming become a viable option. If we consider a scenario where both threat radars are not collocated, but both operate within the coverage of the X-band APG-81, then the Joint Strike Fighter can point its nose at the radar with the highest power aperture rating, and employ the AESA to jam the remaining radars, assuming that they sit inside the ±60° angular coverage of the AESA, and within its band coverage. Thus assumes the AESA emissions will not be used to target a missile shot against the Joint Strike Fighter.

If these specific conditions are not met, such as by a SAM system with search radars operating outside the band coverage of the AESA, or geographically located such that the AESA cannot be pointed at them, then the Joint Strike Fighter may not survive such engagements frequently.

The root of these survivability problems in the Joint Strike Fighter design is that it provides robust stealth and robust jamming capabilities only in the sector under the aircraft’s nose. Its stealth capability from other angles, and in most bands, is poor or very poor, and without a proper internal jamming suite capable of covering all four quadrants around the aircraft, it is severely restricted in its choices of defensive tactics.

This amounts to a basic failure in technological strategy in the Joint Strike Fighter design. When it was conceived, the X-35 airframe shaping provided potential for respectable stealth capability from most aspects, other than the problematic aft sector which was compromised in mid and lower bands due to the use of the cumbersome axisymmetric engine nozzle. Under these conditions, the design did not require internal ECM, towed decoys, or other active defensive measures, as most threat radars would have only achieved a reliable lock in the aft sector and outside the X-band.

A good discussion of the reasoning initially behind the stealth design of the Joint Strike Fighter is contained in RAND Monograph MR719. It relates required stealth performance to the standoff range of weapons employed, for a range of threat scenarios based on 1997 assessments of Saddam’s Iraq, Iran and North Korea. The study concludes that the “Medium Stealth Fighter” (which became the Joint Strike Fighter) is viable with a 15 NMI or better standoff range glide bomb on Day 1 of an air war, for the postulated opponents and their air defence systems. The tabulated results in Fig 4.10 on page 46 of the RAND monograph are reproduced here for completeness:.......................


Conclusions

The Joint Strike Fighter is demonstrably not a true stealth aircraft in the sense of designs like the F-117A, B-2A and F-22A, as its stealth performance varies much more strongly with aspect and threat radar operating frequency band.

The degradation of the initially intended Joint Strike Fighter stealth performance occurred during the SDD program when a series of design changes made to the lower fuselage of the aircraft resulted in fundamental shaping changes in comparison with the X-35 Dev/Val prototype aircraft. The Joint Strike Fighter SDD design departs strongly from key stealth shaping rules employed in the development of the F-117A, B-2A, and F-22A, or the never built YF-23A and A-12A designs.

As a result the tactical options available to Joint Strike Fighter users when confronted with penetrating modern Integrated Air Defence Systems (IADS) are mostly those necessary to ensure the survival of non-stealthy legacy aircraft types.

The result of these limitations is that the operational economics of a fighter force using the Joint Strike Fighter will be much inferior to a force using a true all aspect stealth aircraft such as the F-22A Raptor.

As with claims made for Joint Strike Fighter air combat capability, claims made for the Joint Strike Fighter concerning the penetration of IADS equipped with modern radars and SAMs are not analytically robust, and cannot be taken seriously.

Moreover, it is clear that future Joint Strike Fighter users will pay a significant price penalty for a stealth capability unable to deliver much, if any, return on such investment.

Das ist nur ein kleiner Ausschnitt betreff der Überlebens Fähigkeit, es wird auf jeden nur denkbaren Aspekt eingegangen genau wie auf die Radar Technik und den Stealth Eigenschaften. Ab Heute bin ich kein Fan der F35 mehr zugleich liefert der Artikel auch eine klare Aussage für mehr F22 anstatt der F35.