F-35 Lightning II vs Dassault Rafale

[spazsinbad]

Early SHORNET development stuff here Mar 1998: http://www.airforcemag.com/MagazineArch ... hornet.pdf (183Kb)

Upgrade Of F/A-18 Fuel Tank Gains Ground
16 Dec 2013 Guy Norris

"... In flight tests, they [CFTs] have shown the potential for marginal drag reduction and other benefits over the unmodified aircraft, despite their size and capacity. With the ability to hold 3,500 lb. of fuel, the tanks could add 260-nm combat range to the Super Hornet and, in the case of the EA-18G Growler electronic-attack version, would extend time on station and bring-back weight.

“Boeing looked at ways of bringing the Super Hornet into the 2030 threat environment in an affordable way, and Northrop Grumman's main role in this was development of the CFT,” says Northrop Grumman F/A-18 programs director and chief engineer, Bob Walke. Revealing more details about the CFT development and plans for the production version, Northrop says the prototype units went from “napkin to first flight” in just 10 months. “The effort began in 2010 with low-level trade study work until 2012, when the decision was made to make a prototype happen quickly,” says Walke. Following a go-ahead in September 2012, the tank design was completed in January 2013, assembly began in May, delivery started in early July and flight tests on a leased F/A-18 were underway in August....

...Shaped for low drag and stealth, the test CFTs were not filled with fuel but were otherwise aerodynamically representative of the production tanks. “We knew it was essentially a zero-drag configuration and, although there was no content in the tanks, we could measure drag through fuel flow. We actually saw a little better performance, as it improves transonic transition,” Walke adds.

In flight tests this August back-to-back comparisons of a “clean” F-18 against the CFT-configured F-18 showed “same or better” fuel flow for the modified aircraft at the same gross weight and Mach 0.84 cruise conditions at 34,000 ft...."

Source: http://aviationweek.com/awin/upgrade-fa ... ins-ground

[2.0] Boeing F/A-18E/F Super Hornet
v1.2.0 / chapter 2 of 2 / 01 apr 18 / greg goebel

"...Several more nations, particularly some of the other current legacy Hornet users, are also interested in the type. In early 2011, Boeing displayed a full-sized mockup of a next-generation F/A-18E, with the "Advanced Super Hornet" featuring:
• A removable conformal fuel tank (CFT) over the root of each wing to extend combat radius by 10% without carriage of external tanks...."

Source: http://www.airvectors.net/avhorn_2.html

[sferrin]

It's nice that the F-16 can reach mach 2, but in what tactical scenario is that likely to be deployed? And will that be enough to warrant the other offsets?

Irrelevant. The claim is that fixed inlet aircraft can't go Mach 2. They can. (Some can.)

[lbk000]

Certainly thank you for disabusing me of my erroneous notion re: VG intakes, but in botsing is more correct in reading between the lines.

What I meant to suggest was that I doubt Mach 2 capability is something given much priority in the J-20's design, just as top end speed is not a particularly high priority for the F-35, since we're all moving into an environment where signature management generally takes precedence.

But in the end, I don't know what I don't know.

[steve2267]

My understanding is that air intake design is a specialty, if not an artform, unto itself. If the intake is fixed geometry, as opposed to variable geometry, one designs the intake for a certain speed, possibly for a small range of speeds, but it will be optimum at one speed. As vehicle speed increases in Mach, the geometry needs to change to match the flow condition. What I have read is that to achieve 2.5 Mach or greater, the inlet geometry really needs to be variable geometry (F-15, SR-71 both had variable geometry. I am not familiar enough with the F-4 Phantom to say whether its intakes were fixed or variable. Am guessing they were variable.) That being said, it might be possible to design an aircraft with fixed geometry inlets for, say, 2.5 Mach, but you might have to fly some sort of flight profile (Rutkowski?) involving a climb to higher altitude, then a dive to go supersonic and then accelerate. Others will (hopefully) correct me where I am wrong.

[spazsinbad]

USN F-4J NATOPS PDF http://www.filefactory.com/file/600hw9n ... 28A%29.pdf (135Mb) "variable engine intake ducts"

[sferrin]

My understanding is that air intake design is a specialty, if not an artform, unto itself. If the intake is fixed geometry, as opposed to variable geometry, one designs the intake for a certain speed, possibly for a small range of speeds, but it will be optimum at one speed. As vehicle speed increases in Mach, the geometry needs to change to match the flow condition. What I have read is that to achieve 2.5 Mach or greater, the inlet geometry really needs to be variable geometry (F-15, SR-71 both had variable geometry. I am not familiar enough with the F-4 Phantom to say whether its intakes were fixed or variable. Am guessing they were variable.) That being said, it might be possible to design an aircraft with fixed geometry inlets for, say, 2.5 Mach, but you might have to fly some sort of flight profile (Rutkowski?) involving a climb to higher altitude, then a dive to go supersonic and then accelerate. Others will (hopefully) correct me where I am wrong.

My understanding of the F-22 and XF8U-3 inlets (which is just based on observation, not some inside knowledge) is that both have ways of adjusting duct pressure / shockwave position they just don't do it with movable parts at the exterior inlet. The F-22 uses these doors here at 0:03 to dump excess air overboard:



The XF8U-3 used these:

Things like ramjet engines (also with fixed inlets. . .though, now that I think about it I seem to have heard of at least one VG inlet ramjet) have inlets optimized for higher speeds and use rocket engines to get there.

[sferrin]

USN F-4J NATOPS PDF http://www.filefactory.com/file/600hw9n ... 28A%29.pdf (135Mb) "variable engine intake ducts"

Yep. That's what those ramps on the inside of the intake are for (you can see the hinge line below):

The Chinese J-8 II and Russian MiG-23 used similar:

Capture.PNG (316.42 KiB) Viewed 83240 times

The F-106s was a bit cleaner:

106.PNG (184.9 KiB) Viewed 83240 times

[steve2267]

sf, appreciate that post.

[zero-one]

Quick question.
Is there a way to reach high supersonic speeds with a non-variable inlet? F-22's top speed is still classified. Some people are nearly certain the top speed can't be more than Mach 2.25 due to the intake design.

[sferrin]

Quick question.
Is there a way to reach high supersonic speeds with a non-variable inlet? F-22's top speed is still classified. Some people are nearly certain the top speed can't be more than Mach 2.25 due to the intake design.

As others have pointed out inlets are generally optimized for a particular speed range. There isn't one that is optimal for zero to Mach 3. I wish there was an inlet designer who could weigh in on this. There was one guy, I think it was on this board, who gave a very good explanation of the F-22s inlet system. Also, as I pointed out, there are more ways than one to skin a cat. The XF8U-3 had a fixed external inlet and it hit Mach 2.39 while being canopy limited. They figured with a glass canopy they could hit Mach 2.6 and possibly Mach 2.9 with water injection.

That said, I swear on baby Jesus, I saw Paul Metz on one of those old Discovery/History/Learning channel productions say the F-22 could go at least Mach 2.42. His exact quote was, "it's fast. I mean it's really fast. The top speed is classified but it'll do 1600 miles per hour".

[f4u7_corsair]

From Defense-Aerospace, a comparison between an F-35 pilot interview (2018) and a Rafale pilot interview (2011) on sensor fusion.

-- F-35: “with the integrated sensor system built into the F-35, the role of data fusion is to provide situational awareness as a service to the pilot and the MADL linked combat force.”

Rafale: “if you receive a track from an AWACS, from your SPECTRA self-protection suite, or from your ‘winger’ at the same time, the system will analyze all the inputs and show you only one track…..Rafales work in a truly networked environment, and are fed targeting and other tactical data from a wide range of coalition sources through the Link 16 datalink.”


-- On an F-16, “The radar will be on one display; the targeting data on another. Perhaps a picture generated from the Link-16 network on another. The human brain is where the information on those separate displays are being fused and translated so that pilot is able to execute the mission.”

On Rafale, “Data from all on-board and off-board sensors are combined into a single tactical picture presented to the pilot on the cockpit’s central color display or, if desired, on one of the lateral displays.


-- The F-16 pilot “might also be working his radio to coordinate the mission as well…. A lot of what’s done in side a fourth-generation aircraft is done over the radio.”

The Rafale pilot “can select the data he wants, combine it with other data, and pass it on to his wingman or to other allied aircraft, ships or ground troops through the Link 16, without speaking a single word on the radio and, if not using the radar, without any transmission whatsoever.”


-- “With the F-35 you have automation via fusion going on….. almost all of a notional ten-minute engagement time to build a good picture, is being done automatically for the pilot in F-35 fusion.”

“To avoid overloading the pilot, the [Rafale’s] central computer prioritizes targets according to the threat they represent, and there are also modes to de-clutter the radar scope. The pilot can also decide to concentrate on a given aspect of the mission, and come back to others aspects.


-- With the F-35, “we have the capacity to third-party target and to distribute the effects desired in the battlespace.”

Rafale’s “Link 16 can also be used to de-conflict assignments with other aircraft without using radios…..The idea that a single aircraft can be re-tasked in flight from reconnaissance to strike to interception during the same sortie is truly revolutionary.

Original sources:
https://sldinfo.com/2018/11/the-f-35-an ... ence-2018/
http://www.defense-aerospace.com/articl ... 80%9D.html

[bumtish]

From Defense-Aerospace, a comparison between an F-35 pilot interview (2018) and a Rafale pilot interview (2011) on sensor fusion.

Yawn. Regurtiation of Giovanni propaganda known & shown to be untrue. The new one is sensor fusion.

Giovanni quoted SLD. he should try this piece from SLD:

https://sldinfo.com/2018/01/the-israeli ... r-history/

“The earlier, fourth-generation jets are excellent at maneuvering and activating sophisticated weapons systems, but they are not able to collect intelligence and independently analyze battle movement.

“The F-35 can do all this by itself in real time, with only one pilot sitting in the cockpit.

“We have never had such an operational capability until today.

“Until now, attack aircraft were operated independently of air support aircraft.

“The former waited to receive analysis of the battle picture that came from the latter.

“But in the F-35, everything is on the same platform, and this is no less than amazing.

“When you connect that to several aircraft, you receive strategic capability for the State of Israel.”

What is described for 4th gens here handing over tracks generated from e.g. AWACS through Link 16to the fighters vs 5th gens with fully automated sensor fusion and battlefield information analyses.

Does this quote from Giovanni sound 4th gen or 5th gen to you?

Rafale: “if you receive a track from an AWACS, from your SPECTRA self-protection suite, or from your ‘winger’ at the same time, the system will analyze all the inputs and show you only one track…..Rafales work in a truly networked environment, and are fed targeting and other tactical data from a wide range of coalition sources through the Link 16 datalink.”

The effect is:

The take away from the article about the IAF is that the combat insight by their most experienced pilot is the total theater threat cockpit situational awareness right after takeoff.

The important point is that with the F-35, even the least experienced Squadron Pilot will also have the same intelligence in that cockpit.

An enemy cannot kill the necessary information so essential to setting up 5th gen aircraft enabled kill webs.

A stealth enabled F/A/E-35 let lose in combat by the best plots will be a huge war tipping advantage for the entire Israeli Defense Forces (IDF).

and from SLD again

“When you take off in this plane from Nevatim [base], you can’t believe it.

“At 5,000 feet, the whole Middle East is there for you in the cockpit.

“You see things, its inconceivable.

“American pilots who visit us haven’t seen anything like it, because they fly over Arizona or Florida, and here they suddenly see the [entire] Middle East as a combat zone – the threats, the different players, at both close range and long range.

“Only then do you grasp the enormous potential of this machine.

“We’re already seeing it with our eyes”

The term sensor fusion has a wide range from basic local sensor fusion combined with plot fusion like Rafale to F-35 with sensor fusion across many flights coupled with massive databases generated from MASINT and ELINT, and of course data from external sources.

F-35 means more sensors sharing much higher fidelity data being processed to a higher level across a much wider network.

All sensor fusions are not equal.

[bumtish]

More from Giovanni briganti's piece:

In the interest of fairness, it must be noted that the F-35 was designed in the mid-1990s but only completed its development phase earlier this year, so while its data fusion may have appeared very advanced at a quarter century ago, it has become more common.

Which is garbage. F-35 was not designed in the mid-1990s, and the avionics and sensor fusion envisoned at that time was pretty basic, more like F-16++ than the epic stuff going in the F-35.

Going by Giovanni's premise Rafale would be a late 1970s early 1980s design...muh duh

Yawn. Briganti writes to those who want to believe...

[f4u7_corsair]

The 90s design argument of his is indeed poor. In all fairness, that only brings the tides even considering the insane amount of people believing the Rafale is a 80s jet, let alone its avionics core, which in its current architecture has been designed in the late 00s/early 10s, with the latest iteration just qualified now.
_____

There's sensor correlation, and there's sensor fusion. All elements indicate that Rafale belongs to the latter.

The only valid point your quote could make is the fact that more sensors = more data. I indeed can't dispute that the F-35 sensors' coverage is larger than its counterparts, namely in the EO/IR reign.

But for the rest, how exactly are the passages you quoted unique to the F-35? Just put another sensor fusion-enabled jet in the same data network (the Middle East example), and you'd get the same. Is the quote assuming that the F-35 produces data for the whole Middle East theater? Because if so, that would be a laughable statement that can't be reasonably supported (unless LM got its hands on alien technology that is omniscient and can detect any element on a whole theater from 5000 ft /s).

It's easy to gather flabbergasted testimonies of pilots coming from aircraft that are not sensor-fusion (or even correlation) enabled if you put them in the seat of such an aircraft, in the appropriate data network environment.

Fact is, none of the quote you mentioned accurately describes the alleged step up from Rafale & counterparts sensor fusion to the F-35s', but merely comparing it to a whole, imprecise "fourth-generation"-related statement, which is a fallacy when you consider the immense gaps in avionics and sensor computing within that said fourth-generation.

[bumtish]

Yes, it is more sensors per aircraft but also sensor correlation across the flights of F-35 coupled with massive databases and automation. And of course wrapped in stealth which Giovanni doesn't have high thoughts of. A lot more parameters gathered shared comprehensively across the fleet in the air.

This means much better detection and identification of foes, and more consistent tracks. It means more options and tactics in the sensors realm. It also means more info on foe. The sensors on flights of F-35 act as one integrated unit, not only doing correlation on each airframe then sharing the track for plot correlation on other aircraft, i.e. supporting each other, rather than being one brain across the airborne units.

It's easy to gather flabbergasted testimonies of pilots coming from aircraft that are not sensor-fusion (or even correlation) enabled if you put them in the seat of such an aircraft, in the appropriate data network environment.

The concept of how the sensor fusion works on Rafale and F-35 are reasonably well known. The Israeli quotes where used to highlight the effect.

And since Briganti thought some pilot quotes from SLD were kosher, then I just added some other, Israeli pilot quotes from the same source that he apparently didn't seem to care about.