More delays for the F-35
Spaz wrote ''I'm patient to wait for testing of the fix mooted. People can speculate how they wish until tests show otherwise. After the land testing comes the carrier testing slated for 2013. In the meantime....''
Spaz, thats fine, and entirely correct from a purely engineering point of view - but this isn't a purely engineering problem, its also a military asset problem where time (and at this stage, credibility) is the crux issue. saying 'oh, we'll find out in 2013 if its going to be problem that requires a complete redesign of the rear half of the aircraft' isn't much use when we're a mere 20 days into 2012, and the current delay in the system, let alone the delay forced by having to completely redesign the bugger, means that these aircraft won't be available to protect UK national interests - which, lets remember, is their one and only function and raison d'etre - until 2020 at least.
i remember when JSF was going to be a fielded force by 2012 , could be maintained at a rough field location by three men, and would cost $60m apiece. i'm afraid that at this stage 'oh, we'll find out next year if we have to redesign the aircraft' isn't the correct answer.
Spaz, thats fine, and entirely correct from a purely engineering point of view - but this isn't a purely engineering problem, its also a military asset problem where time (and at this stage, credibility) is the crux issue. saying 'oh, we'll find out in 2013 if its going to be problem that requires a complete redesign of the rear half of the aircraft' isn't much use when we're a mere 20 days into 2012, and the current delay in the system, let alone the delay forced by having to completely redesign the bugger, means that these aircraft won't be available to protect UK national interests - which, lets remember, is their one and only function and raison d'etre - until 2020 at least.
i remember when JSF was going to be a fielded force by 2012 , could be maintained at a rough field location by three men, and would cost $60m apiece. i'm afraid that at this stage 'oh, we'll find out next year if we have to redesign the aircraft' isn't the correct answer.
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An interesting view 'cokecan' but I have no sympathy nor will the USMC for your F-35C potential problems. Youse can always revert to the F-35B and use EMALS & AAG on your new CVF flat decks to launch / recover UAVs or EW aircraft. All that remains to be seen. If you read the LM's Burbage blurb you will note that the hook is going to be tested soon. Even if there were no current F-35C hook problems there will be no actual carrier testing until 2013 in any event.
http://www.navytimes.com/news/2012/01/dn-design-blamed-for-f35c-tailhook-issues-011712/
"...Tests with the newly modified tailhook should start at Lakehurst, N.J, in the second quarter of this year [2012], Burbage said.
That will give the F-35 program another set of data to study to make sure the new design works as promised. However, until those tests are done, there is no ironclad guarantee that the redesign of the tailhook will work, but Burbage said he is confident of that the modified design will be successful.
"The big test for this airplane is not until the summer of ’13 when we take the Navy jet out to the big deck carrier and do actual traps at sea," Burbage said...."
http://www.navytimes.com/news/2012/01/dn-design-blamed-for-f35c-tailhook-issues-011712/
"...Tests with the newly modified tailhook should start at Lakehurst, N.J, in the second quarter of this year [2012], Burbage said.
That will give the F-35 program another set of data to study to make sure the new design works as promised. However, until those tests are done, there is no ironclad guarantee that the redesign of the tailhook will work, but Burbage said he is confident of that the modified design will be successful.
"The big test for this airplane is not until the summer of ’13 when we take the Navy jet out to the big deck carrier and do actual traps at sea," Burbage said...."
Last edited by SpazSinbad; 19th Jan 2012 at 08:39.
Ecce Homo! Loquitur...
Hmmmm. Reading between the lines, they can't meet a key contractual requirement, and are trying to persuade the customer it's not important. Good luck with that...... 
F-35 May Miss Acceleration Goal
The F-35 Lightning II’s transonic acceleration may not meet the requirements originally set forth for the program, a top Lockheed Martin official said.
“Based on the original spec, all three of the airplanes are challenged by that spec,” said Tom Burbage, Lockheed’s program manager for the F-35. “The cross-sectional area of the airplane with the internal weapons bays is quite a bit bigger than the airplanes we’re replacing.”
The sharp rise in wave drag at speeds between Mach 0.8 and Mach 1.2 is one of the most challenging areas for engineers to conquer. And the F-35’s relatively large cross-sectional area means, that as a simple matter of physics, the jet can’t quite match its predecessors.
“We’re dealing with the laws of physics. You have an airplane that’s a certain size, you have a wing that’s a certain size, you have an engine that’s a certain size, and that basically determines your acceleration characteristics,” Burbage said. “I think the biggest question is: are the acceleration characteristics of the airplane operationally suitable?”
A recent report by the Defense Department’s top tester, J. Michael Gilmore, says that the Navy’s F-35C model aircraft, which has larger wing and tail surfaces, is not meeting requirements for acceleration. The report doesn’t say whether the F-35A and F-35B have hit similar snags.
Richard Aboulafia, an analyst with the Teal Group, Fairfax, Va., said that the revelation was not particularly surprising. “It’s a strike fighter,” Aboulafia said. “It’s not an interceptor; it’s not an F-22.” Aboulafia said it was unclear whether additional engine power could boost acceleration in the difficult transonic regime. So far, doubts about the aircraft’s aerodynamic performance haven’t diminished Lockheed’s sales prospects, he said.
The F-35 transonic acceleration specifications were written based on clean-configuration F-16 Fighting Falcon and F/A-18 Hornet fighter, Burbage said. But unlike the Hornet or the F-16, the F-35 has the same configuration unloaded as it does loaded with weapons and fuel, Burbage said. When an F/A-18 or F-16 is encumbered with weapons, pylons and fuel tanks, those jets are robbed of much of their performance.
“What is different is that this airplane has accelerational characteristics with a combat load that no other airplane has, because we carry a combat load internally,” Burbage said, the F-22 Raptor notwithstanding. Even fully loaded, the F-35’s performance doesn’t change from its unencumbered configuration, he said. In the high subsonic range between Mach 0.6 to Mach 0.9 where the majority of air combat occurs, the F-35’s acceleration is better than almost anything flying.
Thus far, Lockheed has not had issues with the plane’s acceleration, Burbage said. There are top level Key Performance Parameters from which lower level detailed engineering specification are derived and Lockheed’s job is to meet as many of those specifications as possible within the laws of physics, he said.
Discussions are underway about if those original specifications are relevant given the jet’s acceleration in a combat configuration, Burbage added......
F-35 May Miss Acceleration Goal
The F-35 Lightning II’s transonic acceleration may not meet the requirements originally set forth for the program, a top Lockheed Martin official said.
“Based on the original spec, all three of the airplanes are challenged by that spec,” said Tom Burbage, Lockheed’s program manager for the F-35. “The cross-sectional area of the airplane with the internal weapons bays is quite a bit bigger than the airplanes we’re replacing.”
The sharp rise in wave drag at speeds between Mach 0.8 and Mach 1.2 is one of the most challenging areas for engineers to conquer. And the F-35’s relatively large cross-sectional area means, that as a simple matter of physics, the jet can’t quite match its predecessors.
“We’re dealing with the laws of physics. You have an airplane that’s a certain size, you have a wing that’s a certain size, you have an engine that’s a certain size, and that basically determines your acceleration characteristics,” Burbage said. “I think the biggest question is: are the acceleration characteristics of the airplane operationally suitable?”
A recent report by the Defense Department’s top tester, J. Michael Gilmore, says that the Navy’s F-35C model aircraft, which has larger wing and tail surfaces, is not meeting requirements for acceleration. The report doesn’t say whether the F-35A and F-35B have hit similar snags.
Richard Aboulafia, an analyst with the Teal Group, Fairfax, Va., said that the revelation was not particularly surprising. “It’s a strike fighter,” Aboulafia said. “It’s not an interceptor; it’s not an F-22.” Aboulafia said it was unclear whether additional engine power could boost acceleration in the difficult transonic regime. So far, doubts about the aircraft’s aerodynamic performance haven’t diminished Lockheed’s sales prospects, he said.
The F-35 transonic acceleration specifications were written based on clean-configuration F-16 Fighting Falcon and F/A-18 Hornet fighter, Burbage said. But unlike the Hornet or the F-16, the F-35 has the same configuration unloaded as it does loaded with weapons and fuel, Burbage said. When an F/A-18 or F-16 is encumbered with weapons, pylons and fuel tanks, those jets are robbed of much of their performance.
“What is different is that this airplane has accelerational characteristics with a combat load that no other airplane has, because we carry a combat load internally,” Burbage said, the F-22 Raptor notwithstanding. Even fully loaded, the F-35’s performance doesn’t change from its unencumbered configuration, he said. In the high subsonic range between Mach 0.6 to Mach 0.9 where the majority of air combat occurs, the F-35’s acceleration is better than almost anything flying.
Thus far, Lockheed has not had issues with the plane’s acceleration, Burbage said. There are top level Key Performance Parameters from which lower level detailed engineering specification are derived and Lockheed’s job is to meet as many of those specifications as possible within the laws of physics, he said.
Discussions are underway about if those original specifications are relevant given the jet’s acceleration in a combat configuration, Burbage added......
I don't know about telescopic hooks, but the Bucc had a spring at the top of theirs, which, I presume, was to mitigate the initial shock of the arrest. Which, I suppose, made them "telescopish"
"Hook-skip" isn't a wholly new problem. The Gannet used to suffer from it a bit, especially in HMS Hermes which had rather more camber to the deck in the region of the wires than other carriers, so the wire touched the deck even with the bowsprings up. It wasn't a major problem - you just bolted. But it helped if you didn't pull the power back to 'ground idle' as you touched...
Does anyone know the proportion of hook-skips that can be expected with the F35? Every time, sometimes, or once in a blue moon?
"Hook-skip" isn't a wholly new problem. The Gannet used to suffer from it a bit, especially in HMS Hermes which had rather more camber to the deck in the region of the wires than other carriers, so the wire touched the deck even with the bowsprings up. It wasn't a major problem - you just bolted. But it helped if you didn't pull the power back to 'ground idle' as you touched...
Does anyone know the proportion of hook-skips that can be expected with the F35? Every time, sometimes, or once in a blue moon?
aren't quite man enough for the job (no sexism intended and there are other manufacturers of a/c/ systems).
“We’re dealing with the laws of physics. You have an airplane that’s a certain size, you have a wing that’s a certain size, you have an engine that’s a certain size, and that basically determines your acceleration characteristics,” Burbage said.
AFAIK none of these factors, even including the laws of physics, has changed since 2001. So in view of the amazing modelling and simulation technology deployed in the program, one wonders how long they have known that the KPP was at risk.
By the way, there was a chap named Burbage at LockMart a few years ago, who seemed really confident that the program was going swimmingly and was "on track to meet the revised budget, timetable and performance goals set more than two years ago."
At Home And Abroad, Criticism Of F-35 Persists
I wonder if he's any relation?
Spaz - You are missing the most likely reason that the Brits went to the F-35C in the first place, which was that the B was having problems and was (in late 2010) about to be put on a two-year probation. The result was that the UK would go into 2013 with two irrevocably STOVL carriers and potentially no jet. By going CATOBAR they knew that they would always have an option, because the US Navy will always have jets.
My guess is that before the B-to-C switch was announced, the UK went to the US and basically said "Can you guarantee unequivocally that the B will go into service?" and that the answer was "well, er. that's the program of record, but..."
AFAIK none of these factors, even including the laws of physics, has changed since 2001. So in view of the amazing modelling and simulation technology deployed in the program, one wonders how long they have known that the KPP was at risk.
By the way, there was a chap named Burbage at LockMart a few years ago, who seemed really confident that the program was going swimmingly and was "on track to meet the revised budget, timetable and performance goals set more than two years ago."
At Home And Abroad, Criticism Of F-35 Persists
I wonder if he's any relation?
Spaz - You are missing the most likely reason that the Brits went to the F-35C in the first place, which was that the B was having problems and was (in late 2010) about to be put on a two-year probation. The result was that the UK would go into 2013 with two irrevocably STOVL carriers and potentially no jet. By going CATOBAR they knew that they would always have an option, because the US Navy will always have jets.
My guess is that before the B-to-C switch was announced, the UK went to the US and basically said "Can you guarantee unequivocally that the B will go into service?" and that the answer was "well, er. that's the program of record, but..."
Last edited by LowObservable; 19th Jan 2012 at 13:30.
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For once we agree LowObservable. We can only guess about the future.
Despite the turnaround by UK from F-35B to F-35C more options for using either variation on CVF is presented to youse as explained.
Despite the turnaround by UK from F-35B to F-35C more options for using either variation on CVF is presented to youse as explained.
The 'turnaround' from B to C only works if we can remodel the carrier to do cat and trap. I hadn't realised what a massive rebuild that will be. It's not a scab-on or minor mod, to put it mildly. I shall invite an well-informed naval chap to explain here what he has explained to me.
Standby...
Standby...
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Seanethebrave..."To me, the B looks like it's a dead man anyway... and the recent slew of bad news being leaked, makes me think that delays are imminent (USAF/USN IOC 2020?)."
From recent news.....The Marine Corps on Wednesday took delivery of its first two F-35B strike fighter production aircraft. BF-6 and BF-8 arrived at Eglin AFB, Florida, from Lockheed's F-35 assembly plant in Fort Worth, Texas. They are now assigned to the 33rd Fighter Wing that runs Eglin's joint F-35 schoolhouse.
Thought the info might be of interest.
Daz
From recent news.....The Marine Corps on Wednesday took delivery of its first two F-35B strike fighter production aircraft. BF-6 and BF-8 arrived at Eglin AFB, Florida, from Lockheed's F-35 assembly plant in Fort Worth, Texas. They are now assigned to the 33rd Fighter Wing that runs Eglin's joint F-35 schoolhouse.
Thought the info might be of interest.
Daz
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Daz,
I did see that a few days ago... I get the feeling that it's only the concurrency regime that has prompted this though, not the aircraft excelling itself through the test programme. Aren't all the US service jets firmly tethered to the ground at the moment for some sort of safety reason?
I did see that a few days ago... I get the feeling that it's only the concurrency regime that has prompted this though, not the aircraft excelling itself through the test programme. Aren't all the US service jets firmly tethered to the ground at the moment for some sort of safety reason?
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Good news for the F-35B
Lockheed’s F-35B Said to Be Getting Panetta’s Backing - Businessweek
Probation should be over so we can move on and concentrate on other issues.
Probation should be over so we can move on and concentrate on other issues.
Last edited by WhiteOvies; 20th Jan 2012 at 15:46.
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Another carrier hook placement dilemma
Have a look at another carrier hook placement dilemma, this time with the hook placed between the fore & aft wheels. Quite a pitching moment if the speeds are not spot on. Typical landing speeds were around 83-87 kts – with the throttle closed just before touchdown, and like a glider, spoilers 'pickled' to initiate the roundout.
Only a single catch wire was used because of the gear trampling problems.
Only a single catch wire was used because of the gear trampling problems.
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I wonder if the 2015 date for F-35C Sea Trials is an error and really slated for 2013 as has been said for some time now? [I guess one can read also that - without any mention of any F-35C trials or further F-35B sea trials - that the dates above refer to the aircraft actually being embarked?]
Panetta Lifts F-35B Probation Jan 20, 2012 By Amy Butler [email protected] NAS PATUXENT RIVER, Md.
Panetta Lifts F-35B Probation | AVIATION WEEK Lifts F-35B Probation
"...Kelly says he also expects to begin testing a redesigned tailhook for the F-35C in the second half of the year. The current design encountered problems last year when officials attempted rolling tests and the tailhook skipped over the wire owing to its weight [QUE???] and a problem with the dampening system. CF-3 will be the first test aircraft to have the new tailhook installed.
After the initial ship trials with the F-35B last fall, the B model is not expected to go to sea until 2013, with the C model following in 2015, Kelly said...."
Panetta Lifts F-35B Probation Jan 20, 2012 By Amy Butler [email protected] NAS PATUXENT RIVER, Md.
Panetta Lifts F-35B Probation | AVIATION WEEK Lifts F-35B Probation
"...Kelly says he also expects to begin testing a redesigned tailhook for the F-35C in the second half of the year. The current design encountered problems last year when officials attempted rolling tests and the tailhook skipped over the wire owing to its weight [QUE???] and a problem with the dampening system. CF-3 will be the first test aircraft to have the new tailhook installed.
After the initial ship trials with the F-35B last fall, the B model is not expected to go to sea until 2013, with the C model following in 2015, Kelly said...."
Last edited by SpazSinbad; 20th Jan 2012 at 21:09.