For aircraft with side-by-side engines this would be a very bad idea due to assymetric thrust.

Not at all; FJ-44 engine MadRat states has 60 cm fan diameter. There can be many implementations; two engines on F-15 with modified vertical stabilizer roots.

In fact its so easy I believe there are clear mathematical reasons why its never implemented/or even tested yet:

Latest version of FJ-44 powers Citation Jet in pairs, with MTOW weight of 7761 kgs, and has top speed of 835 km/h.

While it has similar wing area to F-16, F-16 weigh 14000+ kgs with full fuel and meaningful payload so even if L/D is same while cruising, it would have twice drag due to twice lift requirement. Assuming CJ needs full thrust to get to 835 km/h, F-16 would need 4 of those engines to get to same speed. This would effectively mean additional 2000 kgs just from the engines, equal L/D dictates an additional 5th FJ-44 is required to overcome the drag comes from the weight of 2500 kg engines.

Even equal L/D assumption is doubtlful, as F-16 is optimized for sustained maneuvering it requires good L/D at higher Gs, unlike Citation Jet which only has to cruise with good L/D at 1G only; Typically optimization to single point yields better results.

One may think “why cruise at 835 km/h or M0,77? It can make F-16 go slower and efficiently”, but no. With slower speeds, Lift drops and aircraft needs to pull greater AOA to maintain level flight at 1G. Greater the AOA, worse the L/D, and while twin FJ-44 equipped engines may work more efficiently, airframe wont.

From F-16 flight manual; F-16 at DI=100 34000 lbs, flying for maximum endurance at S/L (at 460 km/h) has 3677 lb/hr fuel flow. Assuming 0,745 SFC it makes 22 kN of thrust just for maximum endurance. Maximum range comes at higher speeds and necessarily at higher thrust settings: 4265 lb/hr, translating to 25,5 kN with 0,745 sfc.

Point is, FJ-44-3 even in pairs is just too weak to make even an F-16 cruise at a meaningful speeds. Newer -and larger- FJ-44-4A may do it in pairs- for limited speeds, but that is 148 Gallons for each engine by volume, excluding inlet diffuser, nozzle, fuel pumps etc etc, which will also have volume and weight penalties. In total it would easily translate to losing 400 gallons of fuel, adding 2000 kg of equipment, and improving SFC by ~68%. With sufficient fuel, there will be a point this configuration will be more efficient, but again by how much? will it cover the costs of adding such equipment? IMHO it would be easier to just add 400 gallons of fuel to the airframe in place of engines would occoupy (which is pretty much they did with CFTs) and be done with it.

@Nuno Gomes; No, I personally offended no one, I sincerely apologize if you feel offended, and I have no problem with the idea you try to defend. Its the source you posted which is I call idiotic and childish due to several factors.

a) I call it idiotic primarily because its not an apples to apples comparison; range, ceiling, climb rate, fuel economy, and cost effectiveness assesment derives from are all wrong.
For example; fuel economy (or specific range to be accurate); you cannot compare averages/approximations, it changes with altitude and speed; A-10’s specific range changes from 0,015 Nm/lb to way over 0,2 Nm/lb. Note that its lb not gallons, because fuel density also varies; with fuel type and temperature.

Now A-10 can get better *best* specific range than Su-25, it -interestingly- achieves those values at S/L; A-10 gets less fuel efficient with increased altitude, and Su-25 is just the opposite. Su-25 is actually more fuel economic then A-10 when it flies sufficently fast and high. Then I would debate if A-10 is really more economical (in terms of fuel efficency) to operate, if it needs to stick to 15-20k feet altitude and fly fast just to avoid MANPADS.

Another example is ceiling. A-10s ceiling never reach 45000 feet; it is 42500 feet at 25000 lbs (clean A-10C weigh 24950 lbs) at drag index of minus 4. Su-25’s ceiling is 7000 meters for clean aircraft with full fuel load. At equal circumstances, (full fuel clean drag index = 0) A-10’s ceiling is 32000 feet or 9750 meters. Same kind of erroneus comparison is made for range and climb rate too.

b) its childish to say Su-25’s survavibility is poor. Author MAY think its inferior to A-10 (which -i think- isn’t by the way) but calling it “poor” is very childish, as A-10 and Su-25 are among the most survivable flying objects ever build.

Now the facts; Su-25 has 755 kg armor, compared to ~540 kg of A-10s, and it makes 7,7% of total weight, compared to 4,7% of A-10s.

Su-25’s cockpit armor as follows; titanium armor, 24 mm thick at front and sides, 10 mm thick at bottom and back; rear part of the headrest is 17 mm titanium, sides are 6 mm semi-hardened armour steel. Inside the airframe it has two bulkhead armors made of 20 mm and 17 mm, engine attachment assembly also acts as front armor which is 20 mm thick. They are supported by two additional bulkheads 2,5 mm thick. Engine centerline distance is exactly 1500mm, both engine cowlings and the center fuel tank is surrounded by soft material to catch fan blades in case of engine destruction. Minimum distance between fuselage side armor and the engine is 40mm. Engine is only fully armoured at front half and is 25mm thick at the bottom, and 8 mm thick at sides. Rear half lacks side armor, but has 17 mm plating that covers interior half at the bottom, and the fuselage fuel tank. Starting at the aft of the cockpit bathtub, fuselage has 17 mm armor at the bottom, and has varying side armor thicknesses from 20 mm at front to 2,5mm at the middle then to 5 mm at the rear. Avionics bays at the front and ammunition bay is also protected by 18 mm armor. Tail is not armored, but individual actuators are covered with sheet metal.

c) its also childish to say Su-25 is derieved from A-9 because it looks similar. By 16 march 1969, there were 3 aircraft designs on mock-up stage on Sukhoi alone (one ended up Su-25), 3 years before the first flight of A-9. Without knowing anything on the subject, author just pull it out of his ass.

I won’t get more into A-10 vs Su-25 discussion, and not post pictures/graphs here as its way OT. Personally I like A-10 more, I like its uniqueness, it had much more upgrade potential, but neither is sufficient enough to trash Su-25.

Wait… What?? :eek::confused:

He just took an utterly idiotic and childish source and pasted it here. Don’t bother..

SU-25s have similar armour and yet have been downed easily by manpads in Ukraine.

And many have survived hits during Russian invasion of Georgia.

Point is not that Su-25/A-10 are invincible, a lucky shot from 9mm pistol can also bring them down, but chances of them surviving a MANPAD hit is greater than anything else. Plus, they can fly above MANPAD’s operating envelope and make precision strikes with LGBs, something current UAVs or helicopters can’t.

compared to subsonic missiles they may be harder to intercept by CIWS ,but not harder to intercept by SAM (such as RAM , ESSM , SM-2 ,SM-6 ), in fact may be even easier due to their high RCS , IR signature

Is a MiG-31 pulling 5Gs@M2.5 easier to hit by a missile compared to learjet pulling 2Gs @M0,85, only because it has higher RCS and IR signature?

On the extremest example, IF P-700 has 30G limit, it will be able to pull it at M2.0+ and completely immune to RAM,ESSM,SM-2,SM-6 or whatever SAMs you put. Its likely to be lower, around 15Gs, but this is still much difficult target than a exocet making 7-8G evasive turns; its irrelevant that IR/radar homing seeker can track or not, SAM will be much harder pressed to to make corrections in time for a succesful hit.

at the moment , for all missiles they are mutually exclusive
the only in development missiles that have both characteristic is ASM-3 , your guess is irrelevant because such missiles doesnt existed

Really? Then let’s get realistic; at the moment there is no JSM -with expected IOC after 2021- or LRASM-A which doesnt even have an estimated IOC date. Then this makes your discussion even pointless; such missiles will never be see a 5V55 or 9M330 firing Kirov; those ships will either be thoroughly upgraded, or scrapped long before 2021.

US have plenty of supersonic missiles : ASMP , ASMP-A, AGM-69, AQM-37C , AGM-78 , AGM-88 ,ASALM , Hyfly ,GAM-87 Skybolt ,AGM-28 Hound Dog
what stealth missiles that Russian have ?

ASMP is not a US missile. Rest; are powered solid fuelled rockets; I repeat myself; US doesn’t have a engine design (which can sustain supersonic flights for 200nm+ when sea skimming) that can be readily used for Anti-shipping role.

it really simple subsonic missiles is alot smaller , lighter so ship , aircraft can carry more of them =>easier to do saturation attack( Ex :su-33 can carry 1 MOSKIT while 1 F-35 carry 10 JSM )
also while i know supersonic missiles reduce engagement time , as i pointed out , the different isnot huge, only 5-10 seconds

That is a different point, which is not entirely valid either due to two facts; 1-you are stating two different aircraft with one designed almost 40 years later 2- Moskit is an extreme example.

-A MiG-29K can carry 4 Kh-35s or 4 Kh-31As.
-A Su-30M can carry 6 Kh-35s or 6 Kh-31As.

So for platform-vise, there is no difference between number of subsonic and high supersonic missiles carried.

Kh-35; Sea skimming, 990 km/h speed (M0,8), 145 kg warhead, 130 km range.
Kh-31; Sea skimming, 3340 km/h speed (M2.7), 94 kg warhead, 50 km range.

I believe specs speak for themselves; there is no difference between # of missiles carried, Kh-31 is much harder to intercept due to 3.37 times speed, around same destructive power (less warhead more KE), but less range. Kh-31 provides 3x better saturation of defenses due to shortened engagement, at the cost of operational range.

Ship vise its not true either. A Slava carries 16 P-500 missiles, when its US counterpart Ticonderoga carries 8 Harpoons. You can argue Slava could have carried more Kh-35 missiles, but it also can carry smaller yet high supersonic Onyx or Kalibr missiles.

however as i pointed out earlier , supersonic fly much higher and get detected much further aways thus they enjoy very little advantages in time

some supersonic missile even give target more reaction time compared to subsonic one

You pointed out subsonic missiles fly 1m above the ground; a comment I didn’t even bothered responding. All sea skimming missiles fly as low as they can, around 10-20 meters above the sea. Comment of supersonic missiles fly higher is BS, A harpoon/Exocet/Kh-35 etc also cruises high to reach their maximal range. As physics wont change in 10 years, same will surely apply to JSM or whatever new missile is introduced. However when fired at 140 km; A harpoon will cruise high to reach that range, but a P-700 will spend all the route sea skimming, an advantage bigger missile always have compared to smaller one.

A-10 may be costly to operate, but it would be far costlier if you lose a Scorpion/UAV/Grippen or two in the process. A-10 is pretty much invincible againist small arms fire and very likely to make it back home should it be hit by a MANPAD or AAA fire.

then you probably dont know alot of them
AGM-84 harpoon can do terminal mode sea-skim or pop-up maneuvers

Since I was talking about 100 Harpoons vs Kirov, this is the only relevant one; pop up maneuver is not equal to evasive maneuvering. Pop-up attack is pretty counterproductive for attacking a ship with defensive capabilities; it allows better target acquistion for the missile, but opposite is also true.

Either way, point I am making is; there are supersonic AShM that are certainly known to make evasive maneuvers, so your point about “supersonic missiles are easier to hit” is plain wrong. Look at it this way, Russian AShM evolution go towards faster missiles with each generation; why so? They could have easily packed 4 Harpoon-like missiles in place of 1 Moskit on a Sovremenny, or 8 missiles in place of single P-500 or P-700, why waste effort if it doesn’t provide any benefits, let alone providing only drawbacks? Were the russians really incapable of building a harpoon-ski? Or the logic behind such move is that a single fast flying missile provides a capability 8 slower missiles cannot?

while supersonic anti ship missiles can do terminal evasive maneuver too , there no way they can turn as violent and tight as subsonic one

Lift formulae says othervise; Plus, a supersonic missile can pull exponantially greater amount of Gs, making it a much difficult target. Missiles are rated for “target Gs” and not “target turn radius etc” for a reason
I wont get into boring explainations, apart from this;
an object flying at 800 km/h, making 30 degree turn will deviate from its original intercept position by 333 meters in 3 seconds, an object flying at 3000 km/h, making just 15 degree turn will deviate from its original intercept position by 645 meters in 3 seconds. A missile trying to intercept (which is expected to fly for ~10 seconds to reach its target), has to make much greater corrections for a supersonic target. Same also applies to a CIWS firing bullets which has its time to impact; greater the deviation from original course, much harder it is to predict where to shoot. As a most extreme example, there is no CIWS system that could intercept ballistic missiles, even though they fly on the most predictiable flight path. Plus, missile seeker has its limits, I highly doubt an AShM could put 30 degree to its target without losing target lock, but it could certainly put 15 degrees.

actually stealth does relevance because :
1-it make jamming alot more effective ( MALD-J , ALQ-99..etc )
2- anti ship missiles fly really low , thus it very hard for ship radar to distinguish them from sea clutter especially again the very low flying stealth one , in fact it may be questionable that the ship radar can detect stealth missiles like NSM , LRASM at all

1- Jamming is a very complex part of discussion. Speaking of jamming by attacker, Jamming requires direct LOS, and jamming platform needs to fly outside the SAM envelope of the target. Trying to jam a MR-800 or a SPY-1 (or any radar with equivalent power output) at 200-250 km is plain laughable, as jammer’s power output degrades by ^2 and relevance of RCS by ^4. We are talking about detection at 20 km range. Try to jam a Slava/Kirov from any closer range, and you will recieve a 48N6 fired on TVM, or 5V55 fired on home-on-jam. Same would apply to a Tico/Burke when jamming platform will be easily punished by a SM-6 shot. However if target lacks a true area defense, (like Udaloy or a Neustrashimny classes) then you are right, jamming does matter, a jamming platform could close to 20 km range, and actually delay the VLO missiles’ detection time. Jamming from defensive platform is more problematic, as most of the current AShM have home-on-jam capability, and anti-radiation capability.

2-What sea clutter are you talking about? Radar will simply set a very high pulse repetition frequency, and as missile is the only thing that causes such doppler shift, it will shine brightly on the screen. Even the most archaic pulse doppler radars will not have slightest problem distinguishing a missile from sea clutter. VLO won’t matter at 20 km. 300 kW peak output from MR-710, something like 500 kW peak output from MR-800.

no P-700 doesnot detect ship at 300 km , even the Zhuk AE on Mig-29 can only detect a normal destroyer at 200 km , and it obviously alot more modern and powerful compared to P-700 seeker ( you have to remember when a radar looking for a ship it have to look for target again a very clutter background ( the sea ) thus the radar range significantly reduced )

Rechecked, you are right its ARH doesn’t lock at that range. At 300 km it detects target emissions, kinda Anti-radiation mode, irrelevant of target RCS.

also MR-800/700 can only track 20 targets at the same times
http://books.google.co.uk/books?id=4S3h8j_NEmkC&pg=PA279&lpg=PA279&dq=MR-710+track+target&source=bl&ots=hJSsKV12e_&sig=ZNcxiFXBl-yW4jyzhDcV4EoG6e4&hl=en&sa=X&ei=ZaotVJS8LYbe7AbDwYGYAQ&ved=0CCEQ6AEwAA#v=onepage&q=MR-710%20track%20target&f=false

The link you have provided does not open, but I think I know the source book; it says something like this “the associated pomia something processor carries 20 target tracks” isn’t it? If the book is the same, please read the complete page, you will find something like “20 target tracks are carried by each workstation, number can be increased by an order of magnitude by increasing the number of workstations”.

Krivak series with sole MR-755 radar carry 8 baget series workstations, totaling at 160 target tracking capability. Now to be honest, I don’t know how many workstations a Kirov possess, but considering it has two main masts (MR-800 and MR-710), it should be at least double the Krivak’s, meaning 320 target tracking capability. Add to that 1- MR-710 is the bigger version of MR-755 with the purpose of scanning greater volumes, demanding more workstations 2-Kirov/slava classes actually use MR-710 as its medium range radar, and rely on MR-800 for long range scans, which should necessitate much greater target tracking capability 3-Unlike Krivak class, Kirov has long range air defense mission demanding much more emphasis on target tracking than krivak, 4-Unlike krivak class, Kirov has a role as a SAG centerpiece, which demands much greater SA. 5-tracking is related to processing power of workstations, baget series workstations are known to be open architecture and pretty much upgradable as a home pc, its illogical to think ships still operate with same computer hardware designed in 1967. If you want my estimation, Kirov’s target tracking capability can easily be 1000 targets, even more. Same is true for UYK-43 upgraded AEGIS ships, way over 1000; but I will simply stick 100+ for both occasions.

30 km is not exactly close range

Range isn’t the issue, a M2.5 missile covers 0,83 km by each second. 30 km? you have 25 seconds, to make the missile stop.

also since F-22 are said to have RCS = 0.0001 m2 , and JSM , JASSM are alot smaller than F-22 , isnt is fair to say they will have much smaller RCS too , may be in -80 DBsm range

No, no-one would waste billions of $ on covering hundreds of missiles with as-effective RAM, and waste an additional few billion $to specialized storage facilities. Difference between RCS of harpoon and JSM would be more similar to the difference between Rafele and F-16.

Plus, said to have and actually has is a lot of different things. It would be miracle if F-22 has 0,01 RCS on average at its front semisphere.

read

Then US Ship designers are plain idiots to accomodate SPG-62?

the time is pretty much negligible for AESA or PESA radar

3- AESA , PESA scan very fast, it take like a second or less to scan the whole volume , also AEGIS ship have more than 1 SPY-1

Phased arrays switch rapidly and cover the entire range around the ship in milliseconds

You are wrong about all of these, not knowing the working principles, and what you post is useless adverstisment; electronic scanning allows beam steering in miliseconds, it doesnt mean covering entire volume in seconds.

You want to scan 90 degree part of the ship with 50 degree elevation, you have 148 individual modules. Radar can cover that region in milliseconds, but the resolution you get will be 16 by 9. Radar will not actually see anything. Instead in real life, radar will form much tighter beams, covering smaller areas with a resolution where it could actually detect targets. MR-800 requires 3 passes to cover all elevations in interleaved mode, so it takes 15 seconds to cover full 360 degrees for all target types. Its reasonable to assume what limits antenna rotation speed is the signal proccessing of the vertical scanning. Then, it is also reasonable if it had electronic scanning, it would still need 15 seconds to cover full rotation, limited by the signal processing speeds. With improved signal processing, antenna could be rotated faster so it would take less time to detect targets.

Considering the signal processing power limitations apply, time to cover entire 360 degree volume for SPY-1 should be not much different than MR-800 or MR-710. SPY-1 is faster only because, US was generally ahead of Soviets in processing power, but milliseconds? or even 2-4 seconds? Not THAT fast. A clear advantage SPY-1 do brings is that when it detects potentially dangerous targets, it could leave few modules each to track them, and operate rest of the modules to keep scanning the area. A feature MR-800 cannot follow, its blind when its not looking at the targets direction; that is why Russians have specialized tracking radars for their missiles.

no
SPY-1 provide mid course guide by data link ( just like how most fighter guider their Aim-120 with their radar) , at the terminal phase SPG-62 are used because it will be more accurate , however only ESSM really need SPG-62 , SM-2 and RAM both have IIR seeker for their terminal phase , SM-6 have active radar guider

30 km detection = 25 seconds engagment interval, 8-10 seconds to detect, additional 4-8 seconds to react. Around 15 seconds passed, AShM are at 12 km, 10 seconds remaining. No datalink, no inertial guidance, there is only SARH guidance for SM-2 or ESSM. No guidance sharing, they are already at their terminal phase right off the VL tube; Likevise there is no datalink for SM-6 either; its SARH guided (or preprogrammed autopilot -if its capable of such thing) to lock its ARH just like a Maddog AIM-120. I understand your theory as a SM-6 locked on, more targets can be engaged, but there is simply not enough time; lets assume additional 3-4 seconds elapsed for launch, acceleration rotation and target acquistion by SM-6 or whatever missiles, enemy AShM are at 8 km, 7 seconds remaining. Like I’ve said an AEGIS ship without any support will have one shot of 3 missile salvo againist M2.5+ AShM then it has to rely on Phalanx.

actually AEGIS ship is primarily designed to defend itself from saturation AShM attacks while Kirov was designed as anti carrier with it’s missiles

Really? saturate what? and saturated by what? In 1960s there wasnt even a such thing called saturation attacks, as there was nothing to saturate, ships then were completely defensless againist anti-ship missiles. Original AEGIS was designed as an intergated combat system that would have quick enough reaction time to defeat the -then subsonic- Soviet anti-ship missiles.