What is wrong with the Rafale?
I have noticed a lot of discussion on here lately about the Rafale and its inability to compete with the various other late 4th generation designs on the market today. In an effort to shed some light on this issue I have taken a moment to list some of the Rafale's major crippling flaws and their origins.
The single biggest issue with the Rafale, and the common thread throughout most of its major design flaws, is that its design team simply lacked sufficient vision of where the future of fighter aviation was heading.
Throughout the Rafale's design process its designers chose to go with incremental improvements rather than generational leaps in technology. The Rafale was intended to catch up to, rather than leap ahead of, aircraft that were designed years earlier such as the F-16 and Mig-29
. The end result is a somewhat refined, but badly overpriced aircraft that has struggled to even compete with the aircraft it was designed to match, and utterly lacks the potential to compete with newer designs.
The most obvious area where this lack of vision is displayed is in the Rafale's overall layout and its notable lack of signature reduction design features. The Rafale exhibits numerous features that would simply never be incorporated into any design intended to have a reduced RCS, including its prominent intakes, a huge vertical stabilizer, canards, a non-retractable refueling probe, and numerous other probes, protrusions, and other serious RCS offenders. What does this mean?
Late in the Rafale's design process its engineers realized that they had failed to anticipate the key role RCS reduction would play in future designs and scrambled to find ways to reduce the Rafale's RCS.
With minimal experience with RCS reduction and an airframe that was already too far along in its design to be fixed, the end result was of course disappointing. Shaping is the single most important consideration in RCS reduction and the Rafale has too many major flaws to ever be considered stealthy. RAM coatings and last minute saw-tooth edge features are at best minimally effective on an aircraft that is otherwise designed all wrong from the start.
Not only that, but the Rafale's maneuverability proved to be disappointing, comparable to, but only marginally better than that already offered by earlier 4th generation designs and noticeably lacking in comparison to its bigger brother, the Eurofighter. As the US/Israel found with the Lavi design, the improvement in aerodynamic performance available with such a design was insufficient to justfy the cost of creating an entire new airframe and a generational leap in performance would require a new approach.
Like its airframe, the Rafale's pit and interfaces sought to close the gap with earlier 4th generation designs. Drawing its inspiration from the US, the Rafale design team sought to replicate the hands on throttle and stick interface the US had adopted by the time the Rafale entered its design phase.
While the Rafale was largely successful in matching the interfaces seen in US fighters in the early 90s, its designers failed to see the direction future designs were heading. Today the Rafale's pit and human interface are at best mediocre in comparison to those found in other aircraft in production.
It lacks a helmet mounted site, a serious flaw in a WVR fight, and numerous other advanced features such as the Super Hornet's fully decoupled interfaces. Most critically, the Rafale's man machine interface lacks the defining features of a 5th generation design, such as advanced sensor fusion and sophisticated multi-purpose helmet mounted displays.
Probably the most famous and inexcusable design flaw in the Rafale is its unusually small and short ranged radar. While the US launched fully funded AESA programs and prepared for a generational leap in radar performance, for some reason the Rafale was designed with a PESA radar, a technological dead-end. Worse, the Rafale was simply not designed to accomodate a radar of sufficient size to operate effectively autonomously.
Now, although France is working to retrofit an AESA antenna onto its PESA back-end in the Rafale, the nose of the Rafale will simply not accomodate a competitive radar. The best the Rafale can hope to do is close some of its radar performance gap with aircraft like the F-16, but will never be capable of competing with designs like the Eurofighter or Super Hornet.
Finally, one of the most critcal flaws in the Rafale's design is its widely misunderstood "Spectra" self protection jammer and RWR suite. As was done with the F-16 and Super Hornet, the Rafale design team sought to incorporate an internal self protection jammer into the Rafale to improve its survivability against radar guided threats.
The major failure of Spectra was that its development cycle was far far too long and France's semiconductor and computer industry was simply incapable of providing the necessary components to create a truely cutting edge system. By the time it went from the drawing board to production, a period of over 10 years, it was barely able to match systems being offered by Israel and the United States on other 4th generation fighters.
The Spectra self protection jammer simply lacks the processing power, flexibility, and diverse threat response range available on aircraft like the Super Hornet, F-16 block 60, or modern Israeli systems. Not only that, but because of nearly continual funding shortages in development, Spectra lacks now-standard features such as sophisticated towed decoys and next generation jamming waveforms that it simply lacks the processing power or antennas to produce.
Instead, what Spectra offers are relatively simplistic signals generated by its prominent but inflexible and simplistic transmitters.(Based on narrow-band, inefficient MMICs, a constraint imposed by the lack of a domestic supplier for more modern MMICs, the same issue that has plauged France's AESA program.) Spectra is perhaps the least crippling of the Rafale's flaws, because it could potentially be removed and replaced with a more modern system.
Spectra tacks up a relatively large amount of space and power for what it offers, so a modern design could certainly do more with the same space and power supply, but France does not currently have the resources or certain key technologies to contemplate designing or building a system that would approach the power and flexibility of something like the F-35s EW system with its unparalled stealthy low power jamming modes.(and the ability to create incredibly powerful long range jamming modes if its AESA is used as a transmitter.)
So in summary, what went wrong? The Rafale was designed to match and compete with designs in operation in the early to mid 90s, but other design teams around the world were already moving ahead with generational leaps in stealth, electronic warfare, sensor fusion, and network centric concepts. By the time the Rafale design team recognized they had misjudged the direction of future designs, they lacked the resources and time to correct their mistakes. Now they are trying to find some way to obtain more money through exports so they can replace the Rafale's mid-90s radar, computers, jammers, etc so that they can at least keep pace with other 4th generation designs for a few years before being completely surpassed by 5th generation designs.
this is what gambit posted(some one who taught you on radars and stealth,)
The major problem with the SPECTRA-like method of active cancellation is that the system must sample a portion of the seeking radar's pulse train...
Basically...The transmitter turn itself on...Wait for a specified period of time...Then turn itself off. The rise and fall in power level constitute a pulse. Several pulses in a sequence make up a pulse train. How long is that sequence depends on the radar's intention and design. The appropriate analogy is a real locomotive with the gaps between sections.
A sample of several pulses must be studied. If the system take too short a sample in order to study the pulse train's signal characteristics to create a credible cancellation, the rest of the pulse train or next pulse train will reveal the aircraft. If the system take too long a sample, then the aircraft will be revealed anyway by the current pulse train. The seeking and therefore hostile radar can change the characteristics of each pulse train from one to the next.
The hostile radar can change the PRF from one train to the next, forcing the SPECTRA-like system to constantly recalibrate itself. The hostile radar is employing the tactic called 'PRF jittering'. The 'jittering' technique is common when the radar is operating in an electronically dense environment BUT the 'jittering' sequence is predictable. The radar using this technique will remember the exact sequence of the many PRFs and will perform the appropriate correlation to eliminate unwanted signals that may come from other radars in the vicinity. Civilian airports are places of where predictable 'PRF jittering' technique is used.
But for military purposes like ECM and ECCM, predictability is not always desirable and a 'non-cooperative target' is always looking for predictability. If the 'PRF jittering' sequence is known, this SPECTRA-like system will work as advertised. If the 'PRF jittering' sequence is not known, the system will create many anomalous echoes for the seeking radar, one moment the system successfully canceled the pulse train but with the new pulse train with a different pulse train characteristics the system must resample, which at the very least will make the seeking radar operator suspicious. The goal is to make the operator unaware, not suspicious.
A SPECTRA-like system is a good idea in application but not against first-tier militaries. Some second-tier militaries can manage to purchase first-tier radars and they will find the aircraft. The balance between sampling and response is what make the SPECTRA system difficult to employ precisely because of the unpredictability of potential adversaries.
This is why the SPECTRA is best against second and third tier militaries. First tier militaries are moving towards the much more versatile AESA radar system.
There are nine logical radars in ASEA, Each capable of performing independent action. An AESA radar looking for a SPECTRA equipped Rafale will find it through the use of multiple radars, from the same main array. The capability of the AESA is dependent upon the technological sophistication of the country wielding it, of course. There will no digital library possible for the SPECTRA to remember.