Forum: F-35 Lightning II

LowObservable wrote:

Note WRT to the "armed decoy" comment: It's tactically advantageous to the US if a potential adversary is uncertain as to whether US and coalition F-35s differ in their RCS and if so by how much. Also, those differences would be known to a coalition commander - the less stealthy airplanes may not be sent downtown on Day 1. And as sferrin points out, the customers know what their RCS KPPs are. On the other hand, this underlies the point that LM's "fifth-generation" shtick is a gross over-simplification; and raises the issue of whether the US aircraft will be more robust versus developing detection technologies.

(1) There is no question whatsoever that VLO aircrafts will become more detectable in the future.

(2) The question is to what degree and whether a tremendous or a more modest tactical and strategic advantage remains with the operation of stealthy air frames.

(3) What is not in question is that regardless of the developments of future detection systems, or the lack thereof, the F-35 will be more survivable than a Typhoon, Rafale, SU-35 or a Teen. Basically it comes down to these platforms being ALREADY DEFEATABLE, whereas the F-22 and F-35 are YET TO BE DEFEATED.

(4) The radar is the fastest, longest ranged, most efficient and most atmospherics independent volume search tool. Everything else is grossly inferior or carry with them tremendous handicaps as dictated by physics. This is why we built radars and not telescope observatories, laser scanners or sonic echo locators.

(5) Regardless of whether the stealth will eventually become slightly detectable or very detectable by certain niche tools, the very fact that they are extremely difficult to detect wit AWACs, SAM and fighter radars, while 4th generation fighters are not, means a hell of a lot.

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<<What is not in question is that regardless of the developments of future detection systems, or the lack thereof, the F-35 will be more survivable than a Typhoon, Rafale, SU-35 or a Teen.>>

Disagree. In order to obtain LO characteristics, the F-35 designers have had to accept trades: no active jammer, no towed decoy, increased empty weight, lower speed, less supersonic agility, limited weapons flexibility. These trades will all degrade survivability if and when the aircraft is detected, and nobody (literally) claims that LO aircraft are invisible.

LO characteristics are also largely fixed by basic design: the F-35 is as resistant to detection, tracking and targeting as it will ever be, and will become less so as detection systems improve, while EW systems have historically been improved through the airplane's lifecycle.

So while the F-35 should have an advantage in detectability today - as it should given the immense investment in LO and the design trades mentioned above - it's not predetermined that such an advantage will persist for ever.

sferrin,
Ultimately the KPPs should represent what's needed to accomplish the mission against a given threat. Hypothesise, for instance, that the USAF will be the ones to go downtown against fully operational double-digit SAMs on Day 1. Different threat, different KPPs, F-22-common coatings and edges. Exports get the same shape (which everyone can see and pole-model if they want) but with much more generic coatings and edge materials. What's the actual RCS difference? That's where you get into details of waveband and aspect angle which (once again) reflect the expected mission and threat.

LowObservable wrote:

LO characteristics are also largely fixed by basic design

Coatings can improve. Its starting to sound like the effectiveness of absorbing radar has surpassed that of deflecting radar. It is a very big variable that will continue to evolve.

LowObservable wrote:

Disagree. In order to obtain LO characteristics, the F-35 designers have had to accept trades: no active jammer, no towed decoy, increased empty weight, lower speed, less supersonic agility, limited weapons flexibility. These trades will all degrade survivability if and when the aircraft is detected, and nobody (literally) claims that LO aircraft are invisible.

AFAIK the F-35s EWS will include a jamming capability, not to say a very advanced one. Weapons flexibility is limited with full stealth, but can be increased at the expense of stealth, but the aircraft will still be more difficult to detect than non LO/VLO designs.
I agree with the rest of your statement.

Scorpion82 wrote:

LowObservable wrote:

Disagree. In order to obtain LO characteristics, the F-35 designers have had to accept trades: no active jammer, no towed decoy, increased empty weight, lower speed, less supersonic agility, limited weapons flexibility. These trades will all degrade survivability if and when the aircraft is detected, and nobody (literally) claims that LO aircraft are invisible.

AFAIK the F-35s EWS will include a jamming capability, not to say a very advanced one. Weapons flexibility is limited with full stealth, but can be increased at the expense of stealth, but the aircraft will still be more difficult to detect than non LO/VLO designs.
I agree with the rest of your statement.

Let's not forget the effort that's going into making AESA's powerful EW tools in their own right.

The AESA will indeed be a very nice tool. However when looking at electronic attack, consider that in the case of the F-22, the computers are at doing enough work already just doing the core mission of the sensor. F-35? It will probably be the best ( safely exportable ) multimode radar for it's size. As there is a lot of work to be done with software, electronic attack options will depend on cooling available also. Consider also the field of view of the APG-81, and if one is considering electronic attack/jamming, the gear is only useful in that role in it's own band... X-band. This is fine for most things that can kill you: ( small microwave radar in the nose of missiles, air intercept radar in other fighters, AAA gun radar and some SAM radar) sliding below X band you get into some AWACs, and Super SAMs which may be able to guide a weapon with S-band. Of course big search radars are even lower. This is why we support our stealth aircraft with jamming or just flat out killing those longer band emitters asap. That is the big reason for the B-52 SOJ.

Really while I think it is important to worry about what kind of L.O. one will get, I am more worried about it from a consumer report kind of angle: What are you getting for your money? It gets real real tiring hearing all the marketing hype using the word "stealth", and some clueless politician or worse the taxpayer just believes it by the sound of the word. The Israeli Journalist brief showing all of that red area of radars shrinking down is pretty brave of who ever put together the brief Laughing

Especially considering the jet is stealth nose-on, who-knows on the side and some little X band carvings in the nozzle on the rear. The other public slides showing a diagram of the thing weaving through an IADS with it's side and most like would have to be rear exposed sounds brave too. Where's the fire? Best to kill those emitters as you find them.

The word "configuration" is used a lot in various talks about the F-35. That word is used when talking about what can be allowed for export to a customer. The crew chief above talking about Secret-NOFORN in T.O.s in such has a point. Roscoe knows some of this stuff first hand from doing FMS work. He could tell us but he'd have to shoot us.

I would take a F-35 with the lowest quality stealth available. I think as long as someone knows their limitations that's OK. I will wager that even the "U.S." quality stealth on an F-35 isn't something you want to stare down a S-300 or S-400 or Patriot or latests versions of AEGIS/Standard. Not having the bandwith for something like that without other electronic and SEAD/DEAD, decoy, MALD support is taking a knife to a gunfight. Whoever put "go it alone" in the IDF brief should drive through some threat emitters that slide below X-Band and then see what they think. Gee, the circles on the display are all funny colors and show me as being exposed. Surprised

This guy does a good explanation of how a low observable aircraft with defensive jamming support does better than a legacy with defensive jamming support. Just me, if I had the lower quality stealth on F-35, I would want an internal self-protection jammer to help me front side and rear when L.O. by itself was having a hard time breaking a lock. I would also want the ALE-50/55 towed decoy. It works. No you aren't going to drive around with your jammer on however it would be an advantage if you got locked up and your L.O. aspect to the incoming threat, wasn't enough to help.

Flachsbart, Brian M., A Robust Methodology to Evaluate Aircraft Survivability Enhancement Due to Combined Signature Reduction and Onboard Electronic Attack, Adobe Acrobat file, June 1997,Naval Postgraduate School, Monterey, CA
http://handle.dtic.mil/100.2/ADA329367

Attached is a public consumption F-35 slide from a May 2007 brief, off of the LM website. Note how the word "configuration" is used and who they have to go to for approval.

Still, boiled down what did they ask for specifically and are they getting it? "We want best" is hardly objective as is "if it's not what the US has it's crap". Obviously we're never going to see the numbers but somewhere they're sitting on a contract (you'd think). If they aren't getting the numbers that are on the contract then they should start legal proceedings. If they are getting what they agreed to then they should drop it (putting it mildly).

Be interesting to put a package of Block II Super Hornet E/Fs with a mix of G Growlers and through some IADS scenarios and then run a variety of F-35 configs through the same scenario and see who does better.

elp wrote:

Be interesting to put a package of Block II Super Hornet E/Fs with a mix of G Growlers and through some IADS scenarios and then run a variety of F-35 configs through the same scenario and see who does better.

Unless it's tanking up other aircraft I don't know how it would even be a contest. Twisted Evil

Seriously though, given the presence of Growlers in your scenario what would be a case in which Block IIs could do a better job than some F-35Cs?

Well in the case of the C since you brought it up: The G and C-JSF will work as a team. It would be wise for RAAF to someday do the drop in G conversion to some Fs when JSF arrives.... Part of the G gear can jam down into the lower bands and most likely really deliver on some of those electronic attack stories we hear about. Note that a G is an escort jammer and not a stand off jammer. But in any event, a G holding down the low band threats and especially important, jamming lower than X-Band threats that JSF can't stealth its way out of, should make a nice team. Of course G can jam the higher band threats too. In that environment, a threat emitter is going have a real hard time trying to pick up a JSF.

Which brings up another point. One which we might not know. If IDF is the first FMS user, what kind of escort(?), and standoff(?) jamming do they have? Of course IDF is home of the TALD, of which USN uses also. So both those users will be throwing up plenty of decoys. Gs and a JSF should make a good team I would think.

Aviation leak had a good article a few months back stating that a team of Super Fs and Gs work nice together in lab scenarios. The detector even on the F can pick up stuff real well. Also a Super Block II E/F has an on board self protection jammer that can help and if it turns tail on a ground threat, it has 2 ALE-50 (soon 55s). This towed decoy works well.

Unless USAF pumps in real money which it doesn't currently have into some SEAD'/DEAD/ECM solutions.... Supers shooting HARMs with G-Growler support will be where you want to be if there ever is a Super SAM scenario. B-52SOJ still has to actually survive funding all the way. F-22 will work a lot better ( and safer ) with B-52 SOJ.

LowObservable wrote:

<<What is not in question is that regardless of the developments of future detection systems, or the lack thereof, the F-35 will be more survivable than a Typhoon, Rafale, SU-35 or a Teen.>>

Disagree. In order to obtain LO characteristics, the F-35 designers have had to accept trades: no active jammer, no towed decoy, increased empty weight, lower speed, less supersonic agility, limited weapons flexibility. These trades will all degrade survivability if and when the aircraft is detected, and nobody (literally) claims that LO aircraft are invisible.

Active jammer - no, the EWS is expected to have high precision directional jamming capabilities. However, stealth doctrine dictates that unlike 4th generation aircrafts the system will probably not be operated except for end-game self-protective jamming of RF guided AAMs and/or pin-point electronic attack of enemy combatants.

Towed decoy - we don't know if it'll carry one.

Empty weight - the F-35's empty weight is lower than that of the F-18E/F while the aircraft carries 2 tons more internal fuel and packs two huge internal weapon bays. The F-35 is lighter than any other aircraft capable of carrying 8.4 tons of fuel and 5700 lbs of internal ordnance.

Speed - the F-35 is expected to be just as fast as the F-16 or F-18; probably somewhat faster operationally when carrying internal stores and fuel compared to a light teen or Eurocanard carrying an equivalent load.

Supersonic agility - the F-35 will meet or exceed F-16 and F-18 maneuverability. There is no reason to believe that the airframe is somehow unagile at supersonic speeds when a similarly laid out F-22 is superbly agile with or without thrust vectoring.

Weapons capacity - the F-35 is capable of packing 2 to 8 A2G ordnance internally, 4 to 6 AAMs internally or a combination of both. This represents the typical combat load of 4th generation fighters for vast majority of missions. If needed, it will match or exceed F-16/18 and/or Eurocanard ordnance capacity by sacrificing VLO for LO status which still betters the 4th generation types.

LO characteristics are also largely fixed by basic design: the F-35 is as resistant to detection, tracking and targeting as it will ever be, and will become less so as detection systems improve, while EW systems have historically been improved through the airplane's lifecycle.

EWS will improve, but so will stealth coatings and LPI radar software.

So while the F-35 should have an advantage in detectability today - as it should given the immense investment in LO and the design trades mentioned above - it's not predetermined that such an advantage will persist for ever.

I 'll say that an F-35 without stealth is already superior to a teen, Typhoon, Rafale, Gripen or SU-30 in A2A and/or A2G missions. With VLO stealthy it simply dominates the field.

DL,
Only active jamming that's been mentioned is from radar, X-band only, front-sector only.
Towed decoy - well, that's what I said. No provision disclosed or known.
The F-35A weighs 4,500 pounds more empty than Typhoon and the F-35C was at last count 1500 pounds heavier than the F-18E.
F-16 and F-18 represent a 1970s standard of speed/acceleration/maneuver. By the way, apart from thrust vectoring, there are significant differences between the '22 and '35 configurations.
The internal load of the F-35 does not represent "the typical combat load of 4th generation fighters". Even an F-16, a much smaller and 30-year-older aircraft, typically carries 4 x AAMs and 2 - 4 reasonably sized bombs.
"I 'll say that an F-35 without stealth is already superior to a teen, Typhoon, Rafale, Gripen or SU-30 in A2A and/or A2G missions."
I can see you believe that, but I'm really not sure why.

LowObservable wrote:

DL,
Only active jamming that's been mentioned is from radar, X-band only, front-sector only.
Towed decoy - well, that's what I said. No provision disclosed or known.
The F-35A weighs 4,500 pounds more empty than Typhoon and the F-35C was at last count 1500 pounds heavier than the F-18E.
F-16 and F-18 represent a 1970s standard of speed/acceleration/maneuver. By the way, apart from thrust vectoring, there are significant differences between the '22 and '35 configurations.
The internal load of the F-35 does not represent "the typical combat load of 4th generation fighters". Even an F-16, a much smaller and 30-year-older aircraft, typically carries 4 x AAMs and 2 - 4 reasonably sized bombs.
"I 'll say that an F-35 without stealth is already superior to a teen, Typhoon, Rafale, Gripen or SU-30 in A2A and/or A2G missions."
I can see you believe that, but I'm really not sure why.

It's simple... because even without an ounce of stealth, it is superior in all the attributes that matters the most and is performing at parity or at most an immaterial disadvantage in all the attributes that aren't that important.

(1) Sensor package -- there is no question that the F-35 fields the most advanced and most effective radar, IRST, EW and communications suite compared to advanced F-16/18 evolutions, the Typhoon, the Rafale, the SU-27/30/35 and the Gripen.

(2) Kinematics performance -- the F-35 will fly just as fast as the above jets carrying a typical operational ordnance load and possess greater fuel reserves than any of these. The ability to fly clean and use the burner more often and for longer durations before going "bingo" translates into superior kinematics in many situations.

(3) Maneuverability -- extreme tight turning ability is really no longer an important factor given the advent of HOBS missiles, but the F-35 is equal to or better than an F-16/18 in this respect which for all intents and purposes is more than good enough. In terms of high altitude performance and control authority, the F-35 possesses the largest control surfaces area which translates into superior handling at extreme altitudes (50,000~60,000 feet). The low polar moment (heaviest stuff in the airframe being concentrated near the Cg) with extremely aft set lobster tails for maximum leverage and with the entire airframe designed as a cohesive lifting body is modelled after the F-22 which has extremely good airframe performance even without the vectoring nozzles. In fact, other than a little less wing sweep and area the F-35 is basically designed like an F-22.

(4) Ordnance -- the F-35 is compatible with and has available to it the largest and best selection of AAMs and A2G ordnance available.

(5) Operability -- the F-35 has the smallest logistical footprint of any of the above mentioned fighters and such nifty features as having all field replaceable parts accessible and removable using a total of just seven hand tools.

In short, an F-35 without its stealth will still out detect and out shoot an Eurocanard, Teen or SU, while keeping its pilot more aware of what's going on around him. It will do so while flying with comparable and competitive flying qualities to a longer distance, with greater endurance and persistence. And, it'll have higher availability, and require less personnel, equipment and work to keep flying.

DL,

I'm glad it's all so simple to you. I'm going to make one last effort to put the record semi-straight, since having engaged this discussion I feel the need to finish.

Sensor package. (1) It bloody well should be good since IOC is ten to fifteen years later than any of the other aircraft mentioned. (2) Many of those aircraft will be upgraded by then. (3) Although you may argue that the overall sensor package is superior, there are sub-areas where its performance will not be better than that of its rivals - for example, an Su derivative will likely have better detection range due to radar aperture size.

Kinematics & fuel reserves. The F-35A/C has a large internal fuel fraction, which is not bad (although there is a large price in OEW that must be set against the drag of tanks), but ultimately you carry as much fuel as you can lift. For instance, it's not hard to run the numbers on a Typhoon and an F-35A in max-practical-load conditions. The F-35A in that condition has a fractionally greater fuel fraction (0.38 plus vs 0.38 minus) and the same wing loading as an F-105.

Maneuver: The F-35 at extreme altitudes will be penalized by high wing loading and higher effective wing loading (versus canards with no tail down moment) and higher bypass ratio. It also has an ops empty weight 3/4 that of the F-22 with just about half the power and wing.

Ordnance: Best is subjective. Largest? Maybe, sometime.

Operability: Where does the seven hand tools thing come from? I've heard a similar statement made about the engine alone.

None of this is in any way a criticism of the designers. The F-35 was designed around an incredibly difficult requirement which demanded:
* stealth, with 2 x internal JDAMs + 2 x AMRAAMs
* size constrained by STOVL with a single engine
* basic design adaptable to a 140 knot CV approach speed
* basic design capable of accommodating powered lift system
* CV version with superior range (internal fuel) to fully loaded F-18E

It remains to be seen whether setting those requirements was a bright idea. It's also worth noting that, on the road to the F-35, the Pentagon rejected designs with greater potential stealth on three separate occasions.

Forum: F-35 Lightning II

My JSF is stealthier than yours, or is it?