Go Back  PPRuNe Forums > Aircrew Forums > Military Aviation
Reload this Page >

F-35 Cancelled, then what ?

Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

F-35 Cancelled, then what ?

Old 19th Jun 2014, 07:52
  #4641 (permalink)  
 
Join Date: Jun 2009
Location: Earth
Posts: 125
Originally Posted by MSOCS
Entirely valid, and I say that as a fast jet aviator with 20 years experience flying combat aircraft.
Can you give a brief version of what would those valid points be, to avoid reading the entire thread?
NITRO104 is offline  
Old 19th Jun 2014, 08:26
  #4642 (permalink)  
 
Join Date: Apr 2008
Location: The Whyte House
Age: 91
Posts: 1,885
Hard to imagine BVR engagements being authorised - certainly by the UK at least - unless during 'all-out war'.
Willard Whyte is offline  
Old 19th Jun 2014, 11:03
  #4643 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 10,276
AW&ST: 5th-To-4th Gen Fighter Comms Competition Eyed In Fiscal 2015

The U.S. Air Force is planning to request proposals from industry to finally provide needed communications connectivity between fifth- and fourth-generation fighters.

The service has long projected a need for so-called "5th to 4th" capability. This need is made even more urgent as the timeline for fielding the stealthy, fifth-generation F-35 has stretched out due to technical challenges in development and funding limitations at Air Force headquarters. And the service acquired far fewer stealthy F-22s from Lockheed Martin than originally planned, making the ability to connect each one to larger networks critical for campaign planning in future operations. Though called "5th to 4th," a major long-term issue is how to allow for the F-22 and F-35 to communicate without using Link 16 alone, which would compromise their stealthy operations............

The service has proposed a program, the Multi-Domain Adaptable Processing System (MAPS), to address this need with what will likely be a pod to act as a gateway between the two stealthy fighters. It is likely this will be placed on fourth-generation fighters such as the F-16 and F-15 families, thus putting a reliance on the involvement in these older systems to support communications requirements.

The operational concept would be for the stealthy fighters to penetrate behind the "bubble," or threat zone, of air defenses, and communicate with one another by transmitting data through the MAPS system. Though it enhances the communications among combat air forces, this operational concept is dependent upon the availability not only of the stealthy platforms to penetrate forward in a fight, but also on the presence of a fourth-generation fighter orbiting within range to support communications; this will likely add cost to execute certain campaign plans...........
ORAC is online now  
Old 19th Jun 2014, 21:05
  #4644 (permalink)  
 
Join Date: Nov 2011
Location: Tarn et Garonne, Southwest France
Posts: 5,283
MSOCS,

I see where you're coming from. I would also say that the laws of physics haven't changed, despite airborne technology, and the Rules of Engagement don't get any less restrictive. But, most importantly, I think what the guy is saying, goes back to the stuff that others have discussed here: the value of stealth, the true 360 signature, the effectiveness of DASS vs cockpit visibility, the compromises in performance required to meet the so called requirements.

I guess the point is that he is saying all the stuff that lots of thinking people are asking about. The responses are, largely, good news broadcasts about how well the latest VL trials went.

I think there are two distinct issues here. One is the cost/delay thing, that prompts lots of posts about the positive reports about programme progress. The other is capability, g restrictions, lack of manoeuvrability (energy as well as turn), etc. this guy has just talked about the the issues that have been pushed to the rear on this thread.

He understands fighter/bomber capabilities as well or better than any of us. I'm sure there are plenty here that would be happy to discredit him. They are welcome try, but this is the guy that helped design one of the most successful a/c of this era.

A man with no clue? You tell me.

Sorry to go on, but the interview covered a lot of ground.

Just concerns...
Courtney Mil is offline  
Old 19th Jun 2014, 21:38
  #4645 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 10,276
ORAC is online now  
Old 19th Jun 2014, 22:29
  #4646 (permalink)  
 
Join Date: Nov 2011
Location: Threshold 06
Posts: 411
Cant be ars*d to check if this has been on this forum before...If it has I apologise. Corporate hype, yes... but some nice pics and (IMHO) quite an achievement to get an ejectee out with that lift fan door open.

...but then I could be considered biased!


https://www.youtube.com/watch?v=KUZ6...be&sf3368855=1
oldmansquipper is offline  
Old 20th Jun 2014, 02:16
  #4647 (permalink)  
 
Join Date: Jul 2008
Location: Australia OZ
Age: 71
Posts: 1,938
High Performance Airfield Pavements (HPAP) Return on Investment

High Performance Airfield Pavements (HPAP) Dec 2013 NAVFAC NavAir Facilities Command
"...Economics of the Technology: ROI or Payback
The ROI for a single JSF high temperature concrete VL pad was calculated to be 8.15. Expanding value to the ten vertical landing pads that have already been built increases the ROI to 49.96. These numbers take into account the extra initial investment to build and maintain the pads for 30 years compared to having to constantly replace the pads if conventional concrete is used. The ROI for the ASR [Alkali-Silica Reactivity] part of the project is 36 based on the extension of an airfield pavement life from 12 years to more than 60 years....

...Site Implementation and Specific Applications
Thus far a total of ten high temperature VL pads have been built at Eglin AFB, Duke Field, MCAS Yuma, and MCAS Beaufort with another being planned at MCAS Iwakuni. Simulated carrier decks have been built at Duke Field and MCAS Yuma with another being planned at MCAS Beaufort. ASR mitigation techniques are being implemented on all Navy concrete jobs.

As of now the concrete mixes have performed well under laboratory testing. A limited number of vertical landings have occurred on some of the high temperature concrete VL pads and there still has not been damage caused by the JSF...."
https://www.navfac.navy.mil/content/...vfac/Specialty Centers/Engineering and Expeditionary Warfare Center/PDFs/ci_tech_data_sheets/TDS-NAVFAC-EXWC-CI-1402.pdf (83Kb)
SpazSinbad is offline  
Old 20th Jun 2014, 05:34
  #4648 (permalink)  
 
Join Date: Apr 2009
Location: Hotel Gypsy
Posts: 2,830
I guess the answer is hidden in a couple of hundred pages of posts, but can some quickly explain why a fan with a few barn doors is a better solution than a Pegasus (as per Harrier) as far as vertical thrust is concerned? To a non- engineer, the latter seems to be a far smarter solution.
Cows getting bigger is offline  
Old 20th Jun 2014, 06:34
  #4649 (permalink)  
 
Join Date: Dec 2006
Location: UK
Posts: 781
CGB,

Perhaps I can help.

A key issue with STOVL aircraft is combining an effective vertical lift system with a militarily effective up and away airframe. There are plenty of examples of the former being achieved at the expense of the latter, and also the 't'other way round.

The Pegasus concept is brilliant and effective. It's one of the only two STOVL concepts to get into service so far (Harrier and V-22). But it has drawbacks. The main one is that it forces the engine to be located at the centre of mass of the aircraft, which, if you have requirement to go supersonic, isn't a great location. In fact, for any fighter/bomber, it's not optimal. The Boeing X-32 illustrated the drawbacks.

Second, the Pegasus concept leads to a very fat engine, which again makes going supersonic a lot harder.

Finally, the Pegasus idea seems to 'top out' at around 25,000 to 28,000 pounds thrust. JSF needed more than that. UK and the US spent years trying to get Plenum Chamber Burning (PCB) to work and eventually had to give it up.

The F-35 shaft driven lift fan concept concept requires a lot of doors and isn't as simple as the Pegasus. But it's delivered a viable supersonic seagoing STOVL fighter bomber with internal weapons bays and reduced signature. Which was the requirement. It also allowed a reasonably common airframe layout to be used to address a number of other requirements, which was what the US DoD decided to go for in the early 90s.

If you'd like to learn more, do a Google on 'Bevilaqua', and you'll find some good videos of Paul Bevilaqua explaining the physics behind the idea.

Hopefully, JF will tell me if I've gone wrong in this brief explanation

Hope this helps

Engines
Engines is offline  
Old 20th Jun 2014, 08:06
  #4650 (permalink)  
 
Join Date: Jan 2004
Location: Far West Wessex
Posts: 2,545
Going supersonic is, as Engines says, one of the problems of a four-poster Pegasus layout. PCB (afterburning on the front nozzles) was proposed in the early 1960s for the P1154, but was needed for vertical landing - which was probably a non-starter because of hot gas ingestion.

The shaft-driven fan was a great idea in theory but has fallen down a bit on execution and weight control. Maybe lift-plus-lift/cruise would have worked out better, but it is hard to say.

Fundamentally, stealth+STOVL+supersonic is incredibly difficult: STOVL+supersonic, or stealth+supersonic, are tough enough as it is.

Unfortunately, the decision to attempt that solution - further complicated by CV and CTOL versions - was based on very optimistic assessments of performance (driven by weight) and cost (development, production and operation).

The OEW of the F-35B is one-third higher than was hoped for at the start of the program (1996), and we all know about the costs. If that had been known, I don't think the program would have started.
LowObservable is offline  
Old 20th Jun 2014, 08:47
  #4651 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 10,276
The Pegasus concept is brilliant and effective. It's one of the only two STOVL concepts to get into service so far (Harrier and V-22).
Very provincial.....

Yak-38

ORAC is online now  
Old 20th Jun 2014, 08:55
  #4652 (permalink)  
 
Join Date: Dec 2006
Location: UK
Posts: 781
ORAC,

Good catch and my bad. I should have said, 'one of the only two STOVL concepts to go into service and be operationally effective'.

My apologies.

Yak-38 could certainly do STOVLs, VLs, VTOs et al, but its operational payload was extremely limited as was its avionics suite. As far as I remember, it was withdrawn from service after only a few years. It also showed the issues a lift plus lift/cruise layout has to cope with, in particular the hot gases from a lift engine just aft of the intakes. The solution the Russians used was to extend the intakes a long way forward - works, but there is a serious weight penalty.

That's not to say that this concept can't work - but like all powered lift aircraft, the trade offs are complex and the concepts carry quite a lot of risk late into development and test. Sometimes into service.

Hope this helps and thanks for pointing out my omission,

Engines
Engines is offline  
Old 20th Jun 2014, 11:54
  #4653 (permalink)  
 
Join Date: Oct 2002
Location: ɐıןɐɹʇsn∀
Posts: 1,960
'Jump jets' aside. Can someone please tell me (forgive my addled brain..) what advantage the F-35 has in all regimes over the 'adversaries'?

I've been looking at wing area,
F-35A: 460 ft² (42.7 m²) mtow: 70,000 lb

F-22: 840 ft² (78.04 m²) mtow : 83,500 lb
PAK FA: 848.1 ft² (78.8 m²) mtow: 77,160 lb
J-20: 790 ft² (73 m²) mtow: 80,001 lb
and I'm wondering what the outcome would be if the 'see first shoot first' strategy failed at first attempt?

I'm not being cynical, just curious. With that wing area, how the F35 is going to be maneuverable enough to be anything more than a bvr aam/gbu delivery system is beyond me.
Hempy is offline  
Old 20th Jun 2014, 14:51
  #4654 (permalink)  

Do a Hover - it avoids G
 
Join Date: Oct 1999
Location: Chichester West Sussex UK
Age: 86
Posts: 2,206
CGB

Engines has as usual covered your query well.

If I could mention one more issue - dunno if you have come across the term Propulsive Efficiency? Essentially the lower the velocity of any propulsive air stream the less will be the losses of that system and so the greater the efficiency.

The Pegasus uses an exhaust velocity that is high compared to that produced by a typical propeller which is itself high compared to a large heli rotor.

So to utilise a given amount of horsepower in the form of a pure jet in order to give you thrust will be less good than using that same horsepower to drive a fan (as in the B).

The X32 used Harrier principles of pure jet thrust but managed to hover a weight some 8000lb less than the X35 using a fan and the same basic engine. This was just down to the propulsive efficiency effect.

Of course in the case of the B the greater propulsive efficiency is only achieved at the expense of much complexity and potential unreliability, cost and weight . However it was still judged by our betters to be the solution of choice.

I am afraid I am not a big fan of the B for the USMC because I think a spec that calls for supersonics and stealth in the CAS role is wrong , especially if you throw in austere sites. But that is a whole different topic.

I completely agree that should a customer insist on having a supersonic vertical lander then the B has the best configuration to achieve this that we know of today. If the guys currently working on anti-gravity paint get a breakthough then that may of course change.
John Farley is offline  
Old 20th Jun 2014, 16:44
  #4655 (permalink)  
 
Join Date: Aug 2007
Location: London, New York, Paris, Moscow.
Posts: 3,632
Hempy..

The correct answer is that "they" will never see it [coming].

Now if you believe the hype......
glad rag is offline  
Old 20th Jun 2014, 17:21
  #4656 (permalink)  
 
Join Date: Jun 2009
Location: Earth
Posts: 125
Gen.Hostage dispelled that hype in his last interview...
Both F-22s and F-35s will be spotted at range by low frequency radar.
NITRO104 is offline  
Old 21st Jun 2014, 17:59
  #4657 (permalink)  
 
Join Date: Aug 2007
Location: London, New York, Paris, Moscow.
Posts: 3,632
And not forgetting..Chinese Air Chief Tells Lockheed ?I Love? The F-35 Breaking Defense - Defense industry news, analysis and commentary
glad rag is offline  
Old 23rd Jun 2014, 20:14
  #4658 (permalink)  
 
Join Date: Jul 2008
Location: Australia OZ
Age: 71
Posts: 1,938
Pilot Safe F-35A Fire Eglin AFB

BREAKING: Fire Breaks Out on F-35 at Eglin Air Force Base, Pilot Safe
23 Jun 2014 Dave Majumdar and Sam LaGrone
"This is a breaking news event. This post will be updated with additional information as it becomes available.

A Lockheed Martin F-35 Joint Strike Fighter was severely damaged — possibly destroyed — in a Monday morning fire on the runway at Eglin Air Force Base, Fla., USNI News learned.

No injuries were reported and officials have begun an investigation into the incident, defense officials told USNI News on Monday.

“The aircraft was preparing to conduct a continuation training mission at the time of the incident, but aborted during takeoff at Eglin Air Force Base due to a fire in the back end of the aircraft,” according to a Monday statement provided to USNI News from the Air Force.

“Emergency responders extinguished the fire with foam.”

The aircraft was a F-35A — the Air Force variant of the fighter — assigned to the 33rd “Nomads.”...

...This is the first incident this severe for the JSF during the life of the tri-service program...."
http://news.usni.org/2014/06/23/breaking-f...base-pilot-safe

Last edited by SpazSinbad; 23rd Jun 2014 at 20:15. Reason: frmt
SpazSinbad is offline  
Old 23rd Jun 2014, 23:45
  #4659 (permalink)  
 
Join Date: Mar 2009
Location: Perth Western Australia
Age: 53
Posts: 809
Actually I just wondered if they just want to give the Chinese a license to manufacture, we can then just by the cheap Chinese models Presuming the Chinese honey pots did a complete job of course in getting the plans..

On a serious note.

Has anyone done any sort of statistics on historical fighter R&D and roll outs, accidents, cost overruns, time over runs. Would be a good comparison. As long as its done on a relative term. Its all well and good to pull headlines out of newspapers to support a positive or negative viewpoint, but that can be misleading.
rh200 is offline  
Old 24th Jun 2014, 05:40
  #4660 (permalink)  
 
Join Date: Apr 2009
Location: Sydney
Age: 41
Posts: 244
Just to add a question leading from the post above, have any F-35s been lost as yet? I'm pretty sure no FSD aircraft were lost and will do a google check when I get the chance. Thinking back to other fighters over the last forty or so years I think only the F-15 and F-22 lost no FSD aircraft. One YF-22 was lost though.

Last edited by dat581; 24th Jun 2014 at 06:01.
dat581 is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.