What is up with the F-35? Part II

[Loke]

Loke, I re-read my post, and it comes off as a bit abrasive and argumentative. If so, I apologize. You asked some honest and hard questions.

No worries -- I am a layperson, and I realize that laypersons like myself often make silly statements :)

The time of flight of an AIM-9 is measured in a handful of seconds. It is a mach 3+ sliver with a smokeless motor. Pretty much impossible to visually acquire.

Would an automatic IR detection system not be able to detect it? E.g. something like the DDM-NG, linked to SPECTRA?

http://www.mbda-systems.com/mediagal.../ddm_ng_ds.pdf

A handful of seconds seems like ages to modern computers, they can perform billions of calculations per second...

Open the distance a bit - make it 10 miles or greater. Now, the separating aircraft has an advantage, and it is very difficult for the attacker to chase down the separating jet. This is due to the kinematics of the tail chase. A separating jet will tend to dive low at 0 G, which produces the best acceleration, and as the altitude drops, missile kinematics also drop enormously due to drag. The envelope shrinks by maybe 75% at sea level vs. higher altitudes.

I am not sure I understand this -- if the separating jet is dropping to produce acceleration, could the chasing jet not also drop and experience the same acceleration? If the chasing jets is faster, would it not be able to close the distance?

"At a distance of about 50 km the Typhoon IRST (Infra-Red Search and Track) system could be capable to find even a stealthy plane “especially if it is large and hot, like the F-22″ as a Eurofighter pilot once said."

The Aviationist » “Raptor’s thrust vectoring not essential” Eurofighter pilot says in last chapter of the F-22 vs Typhoon saga

The F-35 is somewhat smaller; still I guess it should be possible to detect at quite a distance with modern IR sensors?

I need to look more into the possibility of what you refer to as a "hard kill." There are two reasons I'm thinking it is not yet practical. First (primary) is acquisition of the inbound. If the attack is beam or stern, the best current sensors can do is alert, not track, and it requires a track to be able to guide any counter shot. If the attack is in front, the defender's AI radar may be able to detect + track, but if the decision is made to engage an inbound missile, the processor time involved in doing so successfully means that situational awareness of the inbound threat aircraft is going to go down the drain.

"Officials within Germany's Bodenseewerk Gerätetechnik GmbH (BGT) said that the missile's scanning array imaging infrared (IIR) seeker - developed by the company - can be cued by helmet-mounted sight, by an IR search-and-track sensor, or by the aircraft's missile approach warning system. This would allow the pilot to fire IRIS-T to actively defend against a beyond-visual-range missile attack, by destroying the threat in-flight."

IRIS-T anti-missile claim - Jane's International Defence Review

Saab also mentions this for the Gripen NG (slide 54) http://www.jsfnieuws.nl/wp-content/D...ripen_2009.pdf

[GGTharos]

Would an automatic IR detection system not be able to detect it? E.g. something like the DDM-NG, linked to SPECTRA?

http://www.mbda-systems.com/mediagal.../ddm_ng_ds.pdf

A handful of seconds seems like ages to modern computers, they can perform billions of calculations per second...

You could assume it's something like DAS after it's all 'said and done'. The apertures are probably smaller than those of an IRST, so the range will be less.

I am not sure I understand this -- if the separating jet is dropping to produce acceleration, could the chasing jet not also drop and experience the same acceleration? If the chasing jets is faster, would it not be able to close the distance?

Yes, but if it has a missile chasing after it, the pursuit will be deterred.

"At a distance of about 50 km the Typhoon IRST (Infra-Red Search and Track) system could be capable to find even a stealthy plane “especially if it is large and hot, like the F-22″ as a Eurofighter pilot once said."

The Aviationist » “Raptor’s thrust vectoring not essential” Eurofighter pilot says in last chapter of the F-22 vs Typhoon saga

The F-35 is somewhat smaller; still I guess it should be possible to detect at quite a distance with modern IR sensors?

F-22's are actively cooled. They're not all that hot, and 50km is well within AIM-120D range at altitude.

"Officials within Germany's Bodenseewerk Gerätetechnik GmbH (BGT) said that the missile's scanning array imaging infrared (IIR) seeker - developed by the company - can be cued by helmet-mounted sight, by an IR search-and-track sensor, or by the aircraft's missile approach warning system. This would allow the pilot to fire IRIS-T to actively defend against a beyond-visual-range missile attack, by destroying the threat in-flight."

IRIS-T anti-missile claim - Jane's International Defence Review

Saab also mentions this for the Gripen NG (slide 54) http://www.jsfnieuws.nl/wp-content/D...ripen_2009.pdf

That would make Iris-T pretty special ... hard-kill AAM v AAM is a bit hard to swallow. The missiles are not easy to track by the missile sensor, the kinematics are difficult (that missile is pulling a lot of g probably while trying to track your maneuvering plane), and I really doubt the fuze is set up to fuze on something as small as an AAM.

[Chogy]

Would an automatic IR detection system not be able to detect it? E.g. something like the DDM-NG, linked to SPECTRA?

http://www.mbda-systems.com/mediagal.../ddm_ng_ds.pdf

A handful of seconds seems like ages to modern computers, they can perform billions of calculations per second...

Maybe they can detect it. But what can they do about it? The AIM-9 can vastly outperform any maneuvering by the target, and is strongly resistant to countermeasures.

I am not sure I understand this -- if the separating jet is dropping to produce acceleration, could the chasing jet not also drop and experience the same acceleration? If the chasing jets is faster, would it not be able to close the distance?

The classic old-school separation goes something like this... you are engaged neutral with the enemy in a tight turning fight. To simplify it, let's say you are on opposite sides of a circle, chasing each others' tail. You decide to get out. You cease turning, unload to zero G, and run for it. The enemy still has 180 degrees to turn before he can fire a missile. By the time he has done so, you have kinematically defeated the upcoming missile shot.

This was all based on AIM-7 or equivalent type missiles. All missiles do badly in a tail chase.

But things have changed. With the AIM-9X (High-Off-Boresight capability + JHMCS, Joint Helmet Mounted Cueing System), you can fire at that guy across the circle by simply looking at him. With the AIM-120, you'd still have to complete most of the turn to point at the enemy, lock and fire, but the vastly improved performance of this missile (and Russian equivalents) means it can chase down and kill with ease.

Summary - once anchored and in a turning fight, you'd better kill him, or he WILL kill you. And all of this ignores mutual support, wing men, who can poke a missile into the fight from 5+ miles using that same AIM-9X or equivalent.

"At a distance of about 50 km the Typhoon IRST (Infra-Red Search and Track) system could be capable to find even a stealthy plane “especially if it is large and hot, like the F-22″ as a Eurofighter pilot once said."

The Aviationist » “Raptor’s thrust vectoring not essential” Eurofighter pilot says in last chapter of the F-22 vs Typhoon saga

The F-35 is somewhat smaller; still I guess it should be possible to detect at quite a distance with modern IR sensors?

50 km is close-range work for the Raptor. He will have long since dispatched the IRST-equipped enemy.

"Officials within Germany's Bodenseewerk Gerätetechnik GmbH (BGT) said that the missile's scanning array imaging infrared (IIR) seeker - developed by the company - can be cued by helmet-mounted sight, by an IR search-and-track sensor, or by the aircraft's missile approach warning system. This would allow the pilot to fire IRIS-T to actively defend against a beyond-visual-range missile attack, by destroying the threat in-flight."

This is a new technology and bears observation. As GGTharos says, it is an enormously difficult task to do this. As I mentioned earlier, I think the future of this is in lasers which trash IR seekers, or burn through or prematurely fuze a radar missile. The great challenge is in the tracking of the inbound, not the detection. To reliably track such a target requires a LOT of bulky hardware, including some sort of radar array; not practical on the stern or sides of a small fighter.

[Jimbo]

US grounds all F-35s over engine blade crack

Reason for concern, or is this typical in the development of new engines?

Thanks.

[Chogy]

US grounds all F-35s over engine blade crack

Reason for concern, or is this typical in the development of new engines?

Thanks.

Teething problems... they always happen.

When the F-16 was brand new, they crashed so often, they had a little ditty that went "One a Day in Tampa Bay" with MacDill AFB being the RTU location. And it earned the nick name "Lawn Dart."

[jlvfr]

Teething problems... they always happen.

When the F-16 was brand new, they crashed so often, they had a little ditty that went "One a Day in Tampa Bay" with MacDill AFB being the RTU location. And it earned the nick name "Lawn Dart."

And who can forget the wonderfull early days of using the TF30 engine, specially in the F-14...

[Zinja]

With all the glum and bad press that the F-35 is getting, i don't think there has ever been a program that has been so robustly and thoroughly tested as it. When the customers of F-35 eventually receive this product, I think they will have good reason to be more confident in it than all the previous platforms when they first received them. While there are arguments regarding its performance in the skies, i think overall its customers will be satisfied.

[Jimbo]

Teething problems... they always happen.

When the F-16 was brand new, they crashed so often, they had a little ditty that went "One a Day in Tampa Bay" with MacDill AFB being the RTU location. And it earned the nick name "Lawn Dart."

Thanks, that was my initial thought, but as a lay person it is good to have that thought backed up by one with experience.

[Gun Grape]

Teething problems... they always happen.

And it earned the nick name "Lawn Dart."

Not to be confused with the AV-8A, which was nicknamed the "Carolina Lawn Dart"

[Albany Rifles]

Or the UH-60 "Crashhawk".

Sadly men and women die (less so now) proving early technology.

Think of tests for a new drug.....where do the litany of side effects get discovered?

[bonehead]

I am starting to realize just how lucky the Wright brothers were.

[Doktor]

More electronics and equipment = more possible points of failure. No wonder more tests are needed.

Hope at the end of the day the plane will deliver what's expected from it.

[Chogy]

Apparently, the F-35 is cleared to fly once more after being grounded for cracks.

[FJV]

Wrong application of the management philosphies concurrent engineering and outsourcing.

[surfgun]

So Singapore, is reported to buy the B model.