F-35 Cancelled, then what ?
Ecce Homo! Loquitur...
Engines,
I understood the issue with the AV-8B in GW1 was the nozzle locations at the middle of the fuselage. All AV-8Bs hit by manpad were lost, whilst all F-18s which were hit survived.
Aircraft Survivability
........F/A-18 experience in Desert Storm provides valuable information for assessing fighter aircraft vulnerability to MANPADS. Additional information is available from F/A-18 joint live fire (JLF) tests conducted about 1990 at China Lake, California. Combining these data provides insight into the vulnerability of fighter aircraft and helps identify potential vulnerability reduction concepts.
In Desert Storm, four Marine F/A-18s were hit by MANPADs, and all returned to base safely. All impacts were in the engine bay, on or near the “turkey feathers” of the exhaust section. One aircraft with severe damage to both engines’ exhaust sections was able to fly 125 miles to a recovery base. Two of the aircraft lost one engine, demonstrating the survivability of a twin- engine design. By contrast, four single-engine AV-8B aircraft were hit, and all four were lost.............
The vulnerability of the AV-8B was recognised by the GAO back in the 80s during design:

.......Engine thrust for the AV-8B is provided by a thrust vector- ing nozzle system. The engine has four rotatable nozzles which are mechanically interconnected. The nozzles, which protrude out from the aircraft, emit infrared’signatures which, in some cases, allow the AV-8B to be tracked and fired on from maximum missile ranges. Also, missiles travel faster than the AV-8B, further increasing its susceptibility. According to the Navy, counter-measures are not an adequate solution to this problem.
OPPORTUNITYEXISTS TO ENHANCE SURVIVABILITY
According to the Navy, it is less costly to design survivability into an aircraft than to modify existing aircraft for survivability. Navy officials acknowledged that it is possible to make many of the survivability improvements to the AV-8B before the aircraft goes into full production. They noted, however, that the changes necessary to enhance survivability will increase program costs and will diminish aircraft performance..........
I understood the issue with the AV-8B in GW1 was the nozzle locations at the middle of the fuselage. All AV-8Bs hit by manpad were lost, whilst all F-18s which were hit survived.
Aircraft Survivability
........F/A-18 experience in Desert Storm provides valuable information for assessing fighter aircraft vulnerability to MANPADS. Additional information is available from F/A-18 joint live fire (JLF) tests conducted about 1990 at China Lake, California. Combining these data provides insight into the vulnerability of fighter aircraft and helps identify potential vulnerability reduction concepts.
In Desert Storm, four Marine F/A-18s were hit by MANPADs, and all returned to base safely. All impacts were in the engine bay, on or near the “turkey feathers” of the exhaust section. One aircraft with severe damage to both engines’ exhaust sections was able to fly 125 miles to a recovery base. Two of the aircraft lost one engine, demonstrating the survivability of a twin- engine design. By contrast, four single-engine AV-8B aircraft were hit, and all four were lost.............
The vulnerability of the AV-8B was recognised by the GAO back in the 80s during design:

.......Engine thrust for the AV-8B is provided by a thrust vector- ing nozzle system. The engine has four rotatable nozzles which are mechanically interconnected. The nozzles, which protrude out from the aircraft, emit infrared’signatures which, in some cases, allow the AV-8B to be tracked and fired on from maximum missile ranges. Also, missiles travel faster than the AV-8B, further increasing its susceptibility. According to the Navy, counter-measures are not an adequate solution to this problem.
OPPORTUNITYEXISTS TO ENHANCE SURVIVABILITY
According to the Navy, it is less costly to design survivability into an aircraft than to modify existing aircraft for survivability. Navy officials acknowledged that it is possible to make many of the survivability improvements to the AV-8B before the aircraft goes into full production. They noted, however, that the changes necessary to enhance survivability will increase program costs and will diminish aircraft performance..........
Last edited by ORAC; 11th Dec 2012 at 08:59.
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ORAC,
As I might not have made clear, the Harrier layout, (with two of four nozzles cold and all four shielded to an extent) helped reduce IR susceptibility against early generation threats. Sorry for any confusion.
However, the location of the nozzles mid way along the fuselage always meant that a hit would be more serious than on an aft engined design.
Again, there is complexity, depending on the warhead size, angle of arrival and lots of other classified stuff that (thankfully) I am not up to speed with.
As missiles got more capable, the equation changed. That's again quite a normal state of affairs for this area of aircraft systems design.
I am familiar with the TERMA pod effort on GR7 and Tornado for the 'Stan, and would certainly agree with the Navy's assessment that it is less costly to design survivability into an aircraft than to try to add it on later. That, of course, is where the design of aircraft like the F-35 has headed, where just as much effort has gone into addressing IR signature as in the RF area.
There is absolutely no doubt that two engines offer key advantages in the area of survivability. Unfortunately, as I've pointed out, they also tend to lead to very large aircraft that are unaffordable. Nobody, as far as I know, starts out to design a twin engined aircraft that needs only one engine to achieve its required performance. (As ever, development of aircraft and engines go hand in hand - sometimes the engines lead, sometimes the aircraft)
Hornet may be an exception to the 'two engines too big' rule because: a) it started out as a light weight fighter design (YF-17) and b) the demands of carrier operations acted as a natural brake on weight growth.
Best regards as ever those doing the business,
Engines
As I might not have made clear, the Harrier layout, (with two of four nozzles cold and all four shielded to an extent) helped reduce IR susceptibility against early generation threats. Sorry for any confusion.
However, the location of the nozzles mid way along the fuselage always meant that a hit would be more serious than on an aft engined design.
Again, there is complexity, depending on the warhead size, angle of arrival and lots of other classified stuff that (thankfully) I am not up to speed with.
As missiles got more capable, the equation changed. That's again quite a normal state of affairs for this area of aircraft systems design.
I am familiar with the TERMA pod effort on GR7 and Tornado for the 'Stan, and would certainly agree with the Navy's assessment that it is less costly to design survivability into an aircraft than to try to add it on later. That, of course, is where the design of aircraft like the F-35 has headed, where just as much effort has gone into addressing IR signature as in the RF area.
There is absolutely no doubt that two engines offer key advantages in the area of survivability. Unfortunately, as I've pointed out, they also tend to lead to very large aircraft that are unaffordable. Nobody, as far as I know, starts out to design a twin engined aircraft that needs only one engine to achieve its required performance. (As ever, development of aircraft and engines go hand in hand - sometimes the engines lead, sometimes the aircraft)
Hornet may be an exception to the 'two engines too big' rule because: a) it started out as a light weight fighter design (YF-17) and b) the demands of carrier operations acted as a natural brake on weight growth.
Best regards as ever those doing the business,
Engines
Is the money for stealth aircraft like the F35 thrown out of the window in view of the following ?
passive radar detects stealth aircraft
franzl
passive radar detects stealth aircraft
franzl
Last edited by RetiredF4; 11th Dec 2012 at 13:22.
RF4 - It doesn't make stealth obsolete.
However, it does make it more challenging than it was in the F-117 days, where you could get away with worrying about monostatic radars (transmitter and receiver in the same place), most of them operating in the above-UHF/microwave bands.
What it may mean is (1) that the difference between broadband/all-aspect LO, which really drives towards a tailless blended-body, and the evolved F-117/22/35 approach becomes more important and (2) that stealth still needs to be combined with other techniques and systems - tactics, standoff, EW &c.
However, it does make it more challenging than it was in the F-117 days, where you could get away with worrying about monostatic radars (transmitter and receiver in the same place), most of them operating in the above-UHF/microwave bands.
What it may mean is (1) that the difference between broadband/all-aspect LO, which really drives towards a tailless blended-body, and the evolved F-117/22/35 approach becomes more important and (2) that stealth still needs to be combined with other techniques and systems - tactics, standoff, EW &c.
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Just not sporting....
The particular characteristics of the omnipresent radio signals used for operation enable detection of even objects that are difficult to detect, such as stealth aircraft or stealth ships. A further advantage of the new technology is its increased detection capacity in areas of radar shadow such as mountainous terrain and its capability to locate extremely slow and low flying objects.
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....and b) the demands of carrier operations acted as a natural brake on weight growth.
Perhaps a lesson that can be learnt from the TFX project is that trying to design naval aircraft whilst pandering to land-based requirements can prove difficult. History seems to suggest it is far better to design an outright naval aircraft and then offer it for land-based use afterwards.
What it may mean is (1) that the difference between broadband/all-aspect LO, which really drives towards a tailless blended-body, and the evolved F-117/22/35 approach becomes more important and (2) that stealth still needs to be combined with other techniques and systems - tactics, standoff, EW &c.
That would be the even more money per unit approach, thus less airframes available for the same customer with a limited budget (are there others now or in the future?).
Where will that lead to?
franzl
Easy Street wrote
During the 25th Falklands Anniversary Flypast there were also 4 Hawks from 100 Squadron and FRADU. The Hawks were representing the Sea Harrier/Harrier.
Yahoo! Groups
Apparently three of the Hawk Pilots were ex-Sea Harrier Pilots that had taken part in the conflict.
http://www.pprune.org/3357074-post109.html
http://www.pprune.org/3357429-post111.html
http://www.pprune.org/3352550-post106.html
True, but the only Hawks allowed were (and still are) the Red Arrows
4th Wave - 1 x VC-10, 2 x RAF Hawks, 2 x RN Hawks
XV105 Special marks (101 Sqn 90th anniversary)
XX248/CJ XX247/CM 100 Sqn
XX170/170 XX171/171 FRADU
XV105 Special marks (101 Sqn 90th anniversary)
XX248/CJ XX247/CM 100 Sqn
XX170/170 XX171/171 FRADU
Apparently three of the Hawk Pilots were ex-Sea Harrier Pilots that had taken part in the conflict.
http://www.pprune.org/3357074-post109.html
http://www.pprune.org/3357429-post111.html
http://www.pprune.org/3352550-post106.html
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Stacker,
Good example. The F-111B was a classic example of uncontrolled weight growth, triggered by a twin engined design with swing wings - both of which are known weight drivers. It's interesting that Fort Worth (having been responsible for F-111B) once again experienced severe weight growth problems on F-35. It was, to say the least, unfortunate that they didn't learn the lessons. In their defence, F-111B was many years before F-35 and most of the people involved had retired. Corporate memory loss and all that.
You are absolutely right that designing naval (cat and trap) aircraft usually demands a quite distinct design approach, which has to be informed by a lot of company experience plus a willingness to share information with the USN and, at times, accept direction from them. I also agree with you over transfer of designs from land to sea. I am quite happy to be corrected, but the only land based design that I know successfully moved over to cat and trap operations was the T-45, and that's just a smallish trainer. Even that took a substantial redesign to get it on and off the deck. (Mig-29 and Su-33 are doing STOBAR, (not cat and trap) but I'd love to know what their operational payloads and fatigue lives are).
The design challenge for F-35C (as part of a family of aircraft) is therefore a very severe one, almost as severe as that for the F-35B. Selling a single engined design to the USN was also hard work for the DoD (not LM or Boeing, but the DoD central staffs who drove the JSF concept through). However, the thing that clinched it was the availability of a very advanced and powerful engine that would deliver the necessary level of performance from a 75,000 lb class aircraft.
Retired F4 - I think your quote is absolutely spot on target, and very timely. F-35 is a more 'balanced' stealth combat aircraft design, and I'd suspect that many other techniques and systems are being used to improve survivability.
Best Regards as ever
Engines
Good example. The F-111B was a classic example of uncontrolled weight growth, triggered by a twin engined design with swing wings - both of which are known weight drivers. It's interesting that Fort Worth (having been responsible for F-111B) once again experienced severe weight growth problems on F-35. It was, to say the least, unfortunate that they didn't learn the lessons. In their defence, F-111B was many years before F-35 and most of the people involved had retired. Corporate memory loss and all that.
You are absolutely right that designing naval (cat and trap) aircraft usually demands a quite distinct design approach, which has to be informed by a lot of company experience plus a willingness to share information with the USN and, at times, accept direction from them. I also agree with you over transfer of designs from land to sea. I am quite happy to be corrected, but the only land based design that I know successfully moved over to cat and trap operations was the T-45, and that's just a smallish trainer. Even that took a substantial redesign to get it on and off the deck. (Mig-29 and Su-33 are doing STOBAR, (not cat and trap) but I'd love to know what their operational payloads and fatigue lives are).
The design challenge for F-35C (as part of a family of aircraft) is therefore a very severe one, almost as severe as that for the F-35B. Selling a single engined design to the USN was also hard work for the DoD (not LM or Boeing, but the DoD central staffs who drove the JSF concept through). However, the thing that clinched it was the availability of a very advanced and powerful engine that would deliver the necessary level of performance from a 75,000 lb class aircraft.
Retired F4 - I think your quote is absolutely spot on target, and very timely. F-35 is a more 'balanced' stealth combat aircraft design, and I'd suspect that many other techniques and systems are being used to improve survivability.
Best Regards as ever
Engines
Engines,
Not sure where your commentary about IR missiles vs Harrier and Tornado comes from but it is fair way off the mark. Thankfully the truth is classified and not forum fodder.
Not sure where your commentary about IR missiles vs Harrier and Tornado comes from but it is fair way off the mark. Thankfully the truth is classified and not forum fodder.
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Engines,
Not sure where your commentary about IR missiles vs Harrier and Tornado comes from but it is fair way off the mark. Thankfully the truth is classified and not forum fodder.
Not sure where your commentary about IR missiles vs Harrier and Tornado comes from but it is fair way off the mark. Thankfully the truth is classified and not forum fodder.
wots that black Omega doin up there
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Getting the RCS of an aircraft down to the size of a bee is very impressive, but how many bees are capable of 600kts?
I'd assume that this anomaly would stand out like a sore thumb, and a bit of radar computing power would raise the necessary alarm bells. ;-)
I'd assume that this anomaly would stand out like a sore thumb, and a bit of radar computing power would raise the necessary alarm bells. ;-)
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ORAC. If you want to know on the survivability, perhaps you should start at the testing
http://www.bahdayton.com/surviac/asn...012_V9_web.pdf
Quote:
The FUSL testing conducted on AA-1 was very successful meeting all defined test objectives and success criteria. Addressing synergistic effects, the electrical power and flight control systems successfully isolated failures and protected the redundancies built into these systems, allowing continued safe flight. The VSN architecture is robust, providing multiple paths to transfer data. Testing highlighted that fire is a significant threat to flight critical systems. The test team was able to verify that the actual ballistic damage response correlated very well to previous pilot in the loop simulator testing. Over the course of the test program, the LFT team witnessed firsthand the robustness of the F35 flight critical systems, no cheap system kills.
http://www.bahdayton.com/surviac/asn...012_V9_web.pdf
Quote:
The FUSL testing conducted on AA-1 was very successful meeting all defined test objectives and success criteria. Addressing synergistic effects, the electrical power and flight control systems successfully isolated failures and protected the redundancies built into these systems, allowing continued safe flight. The VSN architecture is robust, providing multiple paths to transfer data. Testing highlighted that fire is a significant threat to flight critical systems. The test team was able to verify that the actual ballistic damage response correlated very well to previous pilot in the loop simulator testing. Over the course of the test program, the LFT team witnessed firsthand the robustness of the F35 flight critical systems, no cheap system kills.
Ecce Homo! Loquitur...
Morning.
The F-35 may have passed a phase of testing but still has areas of vulnerability. Firstly such a Heath Robinson VSTOL reconfiguration has to be highly vulnerable to battle damage.
Secondly, as part of a continuously active logistics network using ALIS, it's highly vulnerable to cyber attack. It may be possible to safeguard the network (though working in the business, I doubt it, it's a constantly changing battlefield), the problem is can you prove it?
Thirdly, there is the complexity of the actual software/firmware on the aircraft itself. The same issues arise, both of V&V of the system and being able to prove that such a complex system is safe both from bugs and cyber attack?
The F-35 may have passed a phase of testing but still has areas of vulnerability. Firstly such a Heath Robinson VSTOL reconfiguration has to be highly vulnerable to battle damage.
Secondly, as part of a continuously active logistics network using ALIS, it's highly vulnerable to cyber attack. It may be possible to safeguard the network (though working in the business, I doubt it, it's a constantly changing battlefield), the problem is can you prove it?
Thirdly, there is the complexity of the actual software/firmware on the aircraft itself. The same issues arise, both of V&V of the system and being able to prove that such a complex system is safe both from bugs and cyber attack?