The F-35 Thread

[Boagrius]

Being a military planner means being prepared for both scenarios, designers also have to think ahead (which is the reason fighters keep being designed with internally integrated guns and not just the ability to carry external gunpods), so I really can't follow why you would ridicule the other possibility.

 

Yes and infantrymen tend to carry combat knives with them - it doesn't mean anyone is preparing for bullets to stop working any time soon!?

 

Integrated guns have a variety of uses aside from BFM air combat, at relatively little cost - cheap,

, gunning down the occasional opponent that has spent all their energy defending BVR/pre merge missiles, finishing off damaged aircraft, dispensing of lower value/capability targets (eg UAVs) and so on. They are not built in because anyone of note is seriously entertaining the idea that BFM gunfights will be a particularly important aspect of the air to air warfare domain going forward.

 

You'll also note that the overwhelming trend in new design fighter aircraft is to carry a token amount of gun ammunition - totally inadequate for providing any kind of persistence in the air warfare domain and fundamentally NOT indicative of force planners anticipating a scenario where AAMs are rendered so impotent.

 

Halting all missile production & R&D would be just as grave a mistake as not preparing for the possibility that DIRCMs and like will become commonplace amongst the more advanced foes sooner rather than later.

 

Sure, but that "preparation" does not mean defaulting to gun based BFM combat of all things. In reality it's more likely to (for example) trigger a shift to multimodal forms of missile guidance (eg. the Israeli Stunner missile), DIRCM hardening and/or shifts to broader/multispectral IR seekerheads (ref what the Russians have done with Verba) and more emphasis placed on co-operative engagement techniques via data sharing over jam resistant datalinks like MADL. For the umpteenth time, you've provided precisely zero evidence to suggest that this is a likely scenario worth seriously planning for in any theatre or any timeframe whatsoever.

 

If it's all the same to you, the conversation about future propulsion systems seems much more interesting.

Edited November 21, 2016 by Boagrius

[Boagrius]

AFAIK the F-35 is suppose to get a new GE adaptive cycle engine in mid-2020.

 

Such engine would provide 10% more thrust and 30% more fuel saving.

 

PW is sitting up and taking note as well - we seem to have some competition on our hands after all:

 

https://www.flightglobal.com/news/articles/farnborough-pratt-whitney-proposes-block-1-engin-427150/

[Hummingbird]

Yes and infantrymen tend to carry combat knives with them - it doesn't mean anyone is preparing for bullets to stop working any time soon!?

 

Integrated guns have a variety of uses aside from BFM air combat, at relatively little cost - cheap,

, gunning down the occasional opponent that has spent all their energy defending BVR/pre merge missiles, finishing off damaged aircraft, dispensing of lower value/capability targets (eg UAVs) and so on. They are not built in because anyone of note is seriously entertaining the idea that BFM gunfights will be a particularly important aspect of the air to air warfare domain going forward.

 

You'll also note that the overwhelming trend in new design fighter aircraft is to carry a token amount of gun ammunition - totally inadequate for providing any kind of persistence in the air warfare domain and fundamentally NOT indicative of force planners anticipating a scenario where AAMs are rendered so impotent.

 

 

 

Sure, but that "preparation" does not mean defaulting to gun based BFM combat of all things. In reality it's more likely to (for example) trigger a shift to multimodal forms of missile guidance (eg. the Israeli Stunner missile), DIRCM hardening and/or shifts to broader/multispectral IR seekerheads (ref what the Russians have done with Verba) and more emphasis placed on co-operative engagement techniques via data sharing over jam resistant datalinks like MADL. For the umpteenth time, you've provided precisely zero evidence to suggest that this is a likely scenario worth seriously planning for in any theatre or any timeframe whatsoever.

 

If it's all the same to you, the conversation about future propulsion systems seems much more interesting.

 

You seem completely set on the idea that I am talking about a future where every fight will be a gunfight, which is not at all what I am saying. What I am trying to get across is that there's a possibility that future CM tech could render missiles so much less effective that you will encounter many more situations where the gun and therefore maneuvreability will become a very useful thing to have - which is the case if even 20% of missile shots fail. DIRCM is just one thing, more advanced radar jammers are also being developed, infact AFAIK the latter is one of Gripen's selling points, it's advanced radar jammers.

[Boagrius]

You seem completely set on the idea that I am talking about a future where every fight will be a gunfight, which is not at all what I am saying.

 

Simply responding to this:

 

I am not at all confident in the idea that within the next 10-15 years there's no chance of new countermeasure technologies appearing that are capable of reliably defeating/spoofing ANY form of IR or radar guided missile, and to which the ONLY answer is "dumb" weapons.

 

Which is very different to:

 

What I am trying to get across is that there's a possibility that future CM tech could render missiles so much less effective that you will encounter many more situations where the gun and therefore maneuvreability will become a very useful thing to have - which is the case if even 20% of missile shots fail. DIRCM is just one thing, more advanced radar jammers are also being developed, infact AFAIK the latter is one of Gripen's selling points, it's advanced radar jammers.

 

You're just shifting the goalposts now, which is a shame. Again, there are an infinite number of things that are a "possibility" (the fielding of military unicorns, the adoption of Klingon defence shields, the outbreak of world peace and dismantling of all militaries globally) but they're not remotely as relevant as what is likely in a specified theatre and timeframe. As I said, the conversation about new propulsion tech strikes me as much more interesting. I'm out! ;)

Edited November 22, 2016 by Boagrius

[Hummingbird]

Simply responding to this:

 

Which is very different to:

 

You're just shifting the goalposts now, which is a shame. Again, there are an infinite number of things that are a "possibility" (the fielding of military unicorns, the adoption of Klingon defence shields, the outbreak of world peace and dismantling of all militaries globally) but that's not remotely as relevant as what is likely. As I said, the conversation about new propulsion tech strikes me as much more interesting - I'm out! ;)

 

Not shifting goal posts at all, both things are a possibility (i.e. very reliable CM or just 20%) even if one is more likely than the other, but the likelihood necessitates maneuverability & an internal gun. Hence an internally mounted gun and maneuverability are both attributes that designers & planners seem to consistently want to retain when designing a new fighter. Also let's remember that the last time A2A missiles were used in a major conflict there were plenty of misses, and this certainly won't improve against an opponent remotely equal in capability.

 

But let's move on regardless as I don't find this particularly interesting anymore myself, esp. not when comparisons with unicorns & klingons are being presented...

Edited November 22, 2016 by Hummingbird

[mvsgas]

...(which is the reason fighters keep being designed with internally integrated guns and not just the ability to carry external gunpods)...

 

I thought both F-35B/C did not have an internal gun and used gun pods?

 

[Heli]

 

https://www.facebook.com/EdwardsAirForceBase/photos/a.140333572684247.37126.139549732762631/1302621133122146/?type=3&theater

[Hummingbird]

I thought both F-35B/C did not have an internal gun and used gun pods?

 

 

That's true and a departure from the norm. The F-35A which is supposed to serve as THE fighter in many airforces however retains the internal gun.

 

Btw, what's the plan in terms of how long the F/A-18E well be kept onboard carriers?

 

The F-35B will be an excellent replacement for the Harrier as far as I can see btw, an improvement on all parameters besides maybe cost.

Edited November 22, 2016 by Hummingbird

[Darkbrotherhood7]

Btw, what's the plan in terms of how long the F/A-18E well be kept onboard carriers?

 

AFAIK until 2040, to be replaced by the F/A-XX.

[NineLine]

[NineLine]

[Vitormouraa]

 

https://www.facebook.com/EdwardsAirForceBase/photos/a.140333572684247.37126.139549732762631/1302621133122146/?type=3&theater

 

Wait a minute.. did the nose gear...? LOL

[Hummingbird]

Wait a minute.. did the nose gear...? LOL

 

Just an optical illusion, the cable is lying flat on the ground if you look closer :)

[mvsgas]

Wait a minute.. did the nose gear...? LOL

 

Not sure what you mean, going by Hummingbird response, I assume you think the cable/barrier is in the air? I can not tell, but I found this in a F-16 manual;

[ATTACH]152194[/ATTACH]

[probad]

he's saying it looks like the cable got caught by the front strut. it's actually flat on the ground; you would see a more distanced shadow if it was up in the air.

[Hummingbird]

AFAIK until 2040, to be replaced by the F/A-XX.

 

Alright. Now I'm real excited to see what the F/A-XX will be like :)

[Snarf]

I am surprised there is so much interest in an aircraft which even if it operates to spec (which is doubtful) has:

 

Short range;

Mediocre speed;

Poor maneuvering and dog fighting capability;

Low weapons load out with out external (when it has no stealth);

Mediocre stealth;

Incomplete software and has been released with 18 months to 2 years more of development needed according to the program head.

[Boagrius]

I am surprised there is so much interest in an aircraft which even if it operates to spec (which is doubtful) has:

 

Short range;

Mediocre speed;

Poor maneuvering and dog fighting capability;

Low weapons load out with out external (when it has no stealth);

Mediocre stealth;

Incomplete software and has been released with 18 months to 2 years more of development needed according to the program head.

 

It would appear you have been misinformed ;)

[Darkbrotherhood7]

I am surprised there is so much interest in an aircraft which even if it operates to spec (which is doubtful) has:

 

Short range;

 

Short range? Nope.

 

Mediocre speed;

Prove it.

 

Poor maneuvering and dog fighting capability;

 

Do you have any official chart to prove it?

 

Low weapons load out with out external (when it has no stealth

 

Incorrect, the F-35 with external loadout still stealthier than most of the 4.5 gen fighters.

 

Mediocre stealth;

 

Prove it.

[mvsgas]

I wish we could bet,

 

I think Snarf will quote Pierre Sprey and Air power Australia

[Boagrius]

I wish we could bet,

 

I think Snarf will quote Pierre Sprey and Air power Australia

 

Ok you're on - I'm betting Foxtrot Alpha and War is Boring :lol:

 

EDIT: Would love to add Aviation Week, SNAFU Blog or POGO but you only picked two so it's unfair if I get more choices!

Edited November 25, 2016 by Boagrius

[mvsgas]

:thumbup::D

lol, anyone else?

[Esac_mirmidon]

Whats the RCS of a F-35 with external load?

 

And the RCS for the most part of the 4.5 gen. planes?

 

Or you also are speculating without data?

 

Or in your own words. Prove it.

[mvsgas]

click on image to enlarge

Luke Flies 5000th F-35 Sortie

 

Lt. Col. Gregory Frana, 62nd Fighter Squadron commander, celebrates May 19, 2016, at Luke Air Force Base after flying Luke's 5000th F-35 sortie. (U.S. Air Force photo by Airman 1st Class Pedro Mota)

[garrya]

I am surprised there is so much interest in an aircraft which even if it operates to spec (which is doubtful) has:

 

Short range

Range wise , it among the one with longest range with internal fuel

 

Mediocre speed

Poor maneuvering and dog fighting capability

Top speed wise, F-35 is slower than most fighter. But its dogfighting capabilities is not bad. High alpha capabilities should give it very impressive ITR . Moreover , its acceleration in dogfight speed ( around Mach 0.6-0.95 ) is extremely good , better than most fighter aircraft ( including Su-27 and Su-35 ).

Interesting analysis here :

This is from the note of an aerospace engineer. I know there are other engineers in this forum so feel free to review it.

 

 

We have read from a TsAGI report that a Su-27 could accelerate from 600km/h to 1100km/h in 15 seconds, on 1000m, with 18920kg flying weight:

 

 

 

The average acceleration is 9.25m/s2 from 600-1100km/h at 1000m.

 

 

 

 

We have also read from F-35 240-4.2 configuration report that F-35 could accelerate from 0.6-0.95 mach (696km/h-1102km/h) in 17.9 seconds, under Maneuver Weight at 15000 ft (4527 m):

 

 

 

The Maneuver Weight is defined as follows (60% internal fuel, about 5000kg):

(The 540NM combat radius is almost the radius of full internal fuel with JDAMs loaded at take-off (but launched afterwards). I will prove that later in the appendix)

 

The question is: how to convert F-35’s performance at 4527m to 1000m under the same standard? Let’s do it.

 

Calculation standard: Both aircrafts carry the fuel allowance for the same afterburner time.

This standard is justified as follows: If we adopt some conventional standards, such as 50% internal fuel, this will be unfair for the aircraft with very high internal fuel or low fuel consumption. We can obtain that under 18920kg flying weight, Su-27 has only about 2000kg (4400lb) internal fuel, because a Su-27 with 5270kg fuel, 2xR-27 and 2xR-73 missiles, has a total weight of 23430 kg:

 

http://www.sukhoi.org/eng/planes/military/su27sk/lth/

 

So we need to know how much fuel is needed for F35 to have the same afterburner time as a Su-27 with 2000kg fuel. This leads to Theorem 1:

 

Theorem 1: It’s fair to let F-35 carry only 1560kg fuel, for allowance of the same afterburner time as a Su-27 with 2000kg fuel.

 

Proof: The fuel consumption is proportional to engine thrust:

Fuel Consumption=SFC*Thrust*Time.

Modern fighter jet engines all have a specific fuel consumption of about 1.9 (this approximation could be easily verified with published engine data), therefore, since the afterburner thrust of a F135 is 78% of that of two AL-31s, the fuel consumption of F135 is also 78% of that of two AL-31s. The result is 2000kg*78%=1560kg.

Compared to the Maneuver Weight (19000 kg) of F-35, this new fuel standard yeilds a total flying weight of 15600kg, which is a 18% reduction. (15600/19000=82%)

We are facing a new problem: How is engine thrust at 1000m compared to that at 4572m? This leads to theorem 2:

 

Theorem 2: At a given airspeed (subsonic) and from medium to low altitude, engine thrust is proportional to air density.

 

Proof: This could be easily verified with published engine data. This is a very good approximation. You are welcome to use published data (i.e., RD-33 or AL-31 engine performance curves) to verify this theorem.

So, at a given airspeed (for instance, 600km/h), the thrust at 1000m is 1.44 times as big as that at 4572m, because the ratio of air density is 1.44.

We know the comparison of thrust. What about the drag? This leads to theorem 3:

 

Theorem 3: At a given airspeed (subsonic), the drag at 1000m is less than 1.44 times as big as that at 4527m.

 

Proof: The drag is given by:

Drag=½*Drag Coefficient*air density*speed^2*wing area.

Let's compare 1000m and 4527m. The speed is fixed because it is given, and wing area remains unchanged. The air density gives a factor of 1.44. The drag coefficient is almost the same but slightly smaller, because the zero lift drag coefficient is identical, but the lift required to maintain level flight is smaller due to higher air density, which yields a smaller induced drag coefficient. This concludes the proof.

 

Theorem 4: At subsonic acceleration, the speed-time curve is a convex function, or in other words, the faster you fly, the harder you accelerate.

 

Proof: Theoretically, this is because the drag increases so rapidly as you accelerate. This could also be easily verified with published data of some aircrafts, such as:

 

Theorem 4 tells us that, If we have two aircrafts A and B, and aircraft B has the same or better average acceleration in a faster speed interval, then it’s safe to say B can out-accelerate A.

 

Thank you for your patience for reading through the theorem. Now here comes the essential part: performance conversion from 4527m to 1000m.

 

Math notation:

We note a the acceleration, v the air speed, T the thrust, D the drag, m the total mass of aircraft. At a given altitude, the acceleration, the thrust and the drag are not constant, but functions of speed, which is equivalent to write a=a(v), T=T(v) and D=D(v). Their relationship is given by:

 

---equation 1

At 4527m and maneuver weight, F-35 at maneuver weight, accelerates from 0.6-0.95 mach (696km/h-1102km/h) in 17.9 seconds:

 

---equation 2

At 1000m, notations are changed: we note a1000(v) the acceleration, T1000(v) the thrust, D1000(v) the drag, and m1000 the mass. Theorem 1~3 yields:

 

---equation 3

The time required to accelerate from 696km/h-1102km/h at 1000m is given by:

 

--equation 4

The average acceleration in the interval [696-1102km/h] is more than 11.06m/s2. According to Theorem 4, it is safe to conclude that F-35 can out-accelerate Su-27 in subsonic region, with a significant margin of more than 19.5%.

Sukhoi has been advertising Su-35’s acceleration for a while. Su-35 has about 8% increases over Su-27, which is still inferior to F-35.

 

Appendix:

Why the 540NM combat radius is almost the radius of full internal fuel with JDAMs loaded at take-off (but launched afterwards)?

F-35 with JSMs and 2 AMRAAMs loaded when taking off, JSMs released during the mission, has a combat radius of 610NM with internal fuel:

 

 

The JSM is very light and is less than 908 lbs

http://www.dtic.mil/ndia/2014PSAR/albright.pdf

 

SO, with the much heavier 2000lbs JDAM loaded, the combat radius will drop significantly. 540NM is a reasonable figure

 

 

We already know F-35 has some special turning technique which delivers an astonishing 28deg/sec sustained turn:

 

 

With this turning performance, and coupled with strong subsonic acceleration to recover energy, F-35 will become a potent dogfighter once CLAW is opened up and maneuver restrictions are removed.

http://www.f-16.net/forum/viewtopic.php?f=55&t=52510

Low weapons load out with out external (when it has no stealth)

6 internal AAM at block 4 is not that bad

 

Mediocre stealth

That couldnt be more wrong.F-35 stealth capabilities is on par with F-22 and even slightly better

“The F-35 doesn’t have the altitude, doesn’t have the speed [of the F-22], but it can beat the F-22 in stealth.”

http://breakingdefense.com/2014/06/gen-mike-hostage-on-the-f-35-no-growlers-needed-when-war-starts/3/

 

Hostage caused a stir in late spring when, in press interviews, he said the F-35 would be stealthier than the F-22, its larger USAF stablemate. Conventional wisdom had pegged the F-22, with its angled, vectored-thrust engines, as a stealthier machine than the F-35. Hostage also said the F-35 would be unbeatable when employed in numbers, which is why the full buy of aircraft is "so critical."

 

"I would say that General Hostage … is accurate in his statement about the simple stealthiness of the F-35 [with regard] to other airplanes," Bogdan said in the interview. The statement was accurate for radar cross section, as measured in decibels, and range of detectability, he said, and he scoffed at the notion that anyone can tell how stealthy an aircraft is just by looking at it.

http://www.airforcemag.com/MagazineArchive/Pages/2014/December%202014/The-F-35-on-Final-Approach.aspx

Edited November 25, 2016 by garrya