F-35 Cancelled, then what ?
Isn't there already a video of a F-35 doing a rolling landing?
Anyway.. back on topic.
UPDATE: DOD wants to block-buy 450 F-35 jets from Lockheed - 5/29/2015 - Flight Global
Anyway.. back on topic.
UPDATE: DOD wants to block-buy 450 F-35 jets from Lockheed - 5/29/2015 - Flight Global
Engines -
Thanks. I think your assessment of the formal requirements process is about right. On paper, there was no reason that the evolving Preferred Weapon Systems Concept designs needed to look exactly like the Concept Demonstration Aircraft, or that the JORD should be the same as the (quite rudimentary) requirements that the CDAs were designed around.
In theory, either manufacturer could have gone into the final SDD round with a plywood canard triplane as long as they could show traceability from their CDA work. That was indeed Boeing's defense of its quite radically changed PWSC/SDD design.
However, in practical terms the designs were fettered by the choice of engine and lift system, which was set in 1995-96. Which is why (formal requirements be blowed) what they took into SDD was much the same in terms of fuselage length and wingspan as what they started with in CDA.
Thanks. I think your assessment of the formal requirements process is about right. On paper, there was no reason that the evolving Preferred Weapon Systems Concept designs needed to look exactly like the Concept Demonstration Aircraft, or that the JORD should be the same as the (quite rudimentary) requirements that the CDAs were designed around.
In theory, either manufacturer could have gone into the final SDD round with a plywood canard triplane as long as they could show traceability from their CDA work. That was indeed Boeing's defense of its quite radically changed PWSC/SDD design.
However, in practical terms the designs were fettered by the choice of engine and lift system, which was set in 1995-96. Which is why (formal requirements be blowed) what they took into SDD was much the same in terms of fuselage length and wingspan as what they started with in CDA.
Peter WE,
Oh yes, of course there is. In fact here's one from years ago. But it doesn't look very short and it looks a lot like its on a runway, not the surface that the poster was asking about.
https://m.youtube.com/watch?v=vo1xoNoi3uM
Oh yes, of course there is. In fact here's one from years ago. But it doesn't look very short and it looks a lot like its on a runway, not the surface that the poster was asking about.
https://m.youtube.com/watch?v=vo1xoNoi3uM
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JF,
Great post. I'll be calling them SSLs from now on.
Courtney,
I think what this discussion makes clear is that the F-35B (like the Harrier, and also like the V-22) can use its powered lift systems as well as aerodynamic (wing) lift to optimise its landing modes to achieve desired landing distances at various weights. (The USMC have a hard requirement for F-35B SLs to short land strips).
It's a neat trick and one that is achieved with extremely good handling characteristics, low pilot workload and improved safety. And it's largely down to the great input from the BAES team who designed the STOVL flight and propulsion controls, working with LM at Fort Worth and Pax River. I'd really like, just for once, to see their efforts recognised.
Best Regards as ever to those making this powered lift stuff work,
Engines
Great post. I'll be calling them SSLs from now on.
Courtney,
I think what this discussion makes clear is that the F-35B (like the Harrier, and also like the V-22) can use its powered lift systems as well as aerodynamic (wing) lift to optimise its landing modes to achieve desired landing distances at various weights. (The USMC have a hard requirement for F-35B SLs to short land strips).
It's a neat trick and one that is achieved with extremely good handling characteristics, low pilot workload and improved safety. And it's largely down to the great input from the BAES team who designed the STOVL flight and propulsion controls, working with LM at Fort Worth and Pax River. I'd really like, just for once, to see their efforts recognised.
Best Regards as ever to those making this powered lift stuff work,
Engines
Engines, mostly what I've been saying and what I believe too. Once again, your post looks like you thought I was questioning the reason, utility or practicality of a feature of F-35. I was not. I was addressing a question about whether it had yet been trailed in the context of the QE class carrier. My remark about the marines was, in context, about their obvious choice to use VLs on the small ships; the point being that RVLs take space.
But thank you for the update and please don't think I fail to recognise the efforts of good people in the programme.
I shall attempt to be even more clear in my posts to avoid being misunderstood in future.
But thank you for the update and please don't think I fail to recognise the efforts of good people in the programme.
I shall attempt to be even more clear in my posts to avoid being misunderstood in future.
...flight trials carried out using a Harrier, not F-35. So no F-35 handling characteristics, not the full F-35 system, not the F135 engine, not the 2015 software, not the F-35 brakes....
A Harrier trying to simulate an F-35? For proving a concept, fine. But that is still a simulation on a completely different airframe.
A Harrier trying to simulate an F-35? For proving a concept, fine. But that is still a simulation on a completely different airframe.
At the time, in June 2007, with no F-35Bs and QE class ships available, what more could be done?
The interest that raised the question, remember, was weather the F-35 had been tested on a QE sized deck.
. The F-35B has been to a smaller one. As I tried to explain, an aircraft (a real life and death aircraft) with F-35B handling (as best as could be done, but you'll have to look at the response-matching data and judge for yourself) has been to a deck about the right size (PA Charles de Gaulle, so actually a bit smaller and not helpfully lined-up with the ship's wake) at SRVL speeds on an SRVL flightpath (plus or minus the variations induced by several test pilots, not all from the same country).At the time someone (I'm admitting nothing) did suggest the Admiral Kuznetsov. Maybe if the SRVL demo had been done to that deck you'd be happier?
Sorry, I should add it was proving for the Bedford Array, was it not?
NoHoverstop,
All good points. Your first, yes, I see what you mean. It's still simulation, though. And, as you wrote, based on a set of predictions. And, as I wrote, it proved a concept.
Your second, yes, as you spotted I missed out the letter B. Yeah, it's been to a number of decks and runways, but I think the original question that someone asked was more specific. I should go back and look, but not now. Again, I know this will work, but they will still have to do it for real on the actual ship, with the actual aircraft. But they will make it work as it will be very important to bring back for the RN and the RAF.
Final one, I had always thought that the VAAC test/demo (very good
) series was all part of exactly that, a series of trials proving various aspects of projected F-35 ops. So, yes I knew the Bedford Array was towards the end, but I did think it was all part of the same series of tests.
Still, as I said, RVLs (or as John Farley rightly remarks, SSLs) will be an important part of the repertoire, and there's no doubt in my mind that it works. Now they (the Wizards) just have to bring it all together.
All good points. Your first, yes, I see what you mean. It's still simulation, though. And, as you wrote, based on a set of predictions. And, as I wrote, it proved a concept.
Your second, yes, as you spotted I missed out the letter B. Yeah, it's been to a number of decks and runways, but I think the original question that someone asked was more specific. I should go back and look, but not now. Again, I know this will work, but they will still have to do it for real on the actual ship, with the actual aircraft. But they will make it work as it will be very important to bring back for the RN and the RAF.
Final one, I had always thought that the VAAC test/demo (very good
) series was all part of exactly that, a series of trials proving various aspects of projected F-35 ops. So, yes I knew the Bedford Array was towards the end, but I did think it was all part of the same series of tests. Still, as I said, RVLs (or as John Farley rightly remarks, SSLs) will be an important part of the repertoire, and there's no doubt in my mind that it works. Now they (the Wizards) just have to bring it all together.
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It was me who suggested that there had been no testing of an F35B in SSL mode on an area equivalent to that of a QEC class carrier. A reverse Doolittle raid experiment in a way. SSL will be important for the UK, it would seem that there has been no actual testing of SSL concept for a QEC carrier by actual development or test aircraft.
I take thus that it is unclear as to if SSL is physically possible for the F35B to do, irrespective of bring back weight. There is also implicitly uncertainty as to how the software deals with SSL, no doubt it has been tried in a simulator however.
I am sure that people on this side of the pond would feel more comfortable with the project when the ability of the F35B to land at required weight on one of our aircraft carriers and of course take off with a decent load has been at least demonstrated in concept.
I take thus that it is unclear as to if SSL is physically possible for the F35B to do, irrespective of bring back weight. There is also implicitly uncertainty as to how the software deals with SSL, no doubt it has been tried in a simulator however.
I am sure that people on this side of the pond would feel more comfortable with the project when the ability of the F35B to land at required weight on one of our aircraft carriers and of course take off with a decent load has been at least demonstrated in concept.
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Would it be possible to test the SSL on USS Wasp with six F-35B's aboard for operational testing with RN and RAF staff involved? The Wasp is only 27m shorter than Queen Elizabeth but with the ski ramp inplace the length available for an SSL is close enough not to make a difference.
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My point was that SL has not been tried on a runway marked out with the length of a QEC flight deck, better to do this before trying it out an SSL, obviously there are differences however it might be better to prove concept on dry land before trying it afloat. "F35B skids off Wasp's deck and is lost when testing Limey concept" would not be the best PR.
Your proposed way forward makes sense to me, PhilipG and I would expect that to be a step on the way there, again to prove the concept and iron out wrinkles. You probably don't even need the deck markings as long as the pilot can land it consistently in the right place and the Wizards can measure the landing roll for various weights and conditions. They might even do more "hard sums".
At some point, of course, you have to try it on the actual ship to see how it copes with other factors like a moving deck, anomalies like wind-flow around structures, visual effects or proximity to other equipment, etc. That's what test pilots are for once the ships are built.
Presumably all part of the testing and work-up.
At some point, of course, you have to try it on the actual ship to see how it copes with other factors like a moving deck, anomalies like wind-flow around structures, visual effects or proximity to other equipment, etc. That's what test pilots are for once the ships are built
.Presumably all part of the testing and work-up.
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Courtney, besides the obvious Sense and the F35 project possible oxymoron. It would seem that the requirement for SSL has yet to be taken very seriously by the project team, at least in the face of it.
It would be extremely embarrassing, for the UK, if when the version 3F Software comes out that the SSL landing mode had not been sorted out, debugged, or the requirement for crash barriers to be installed on the QEC class because say brake fade or tyre blow outs were causing unacceptable losses of airframes, had not been recognised. Not that I am suggesting that the F35B is as fragile as the initial Seafires.
It would be extremely embarrassing, for the UK, if when the version 3F Software comes out that the SSL landing mode had not been sorted out, debugged, or the requirement for crash barriers to be installed on the QEC class because say brake fade or tyre blow outs were causing unacceptable losses of airframes, had not been recognised. Not that I am suggesting that the F35B is as fragile as the initial Seafires.
Philip,
I don't think that needs to be a concern as work has been undertaken on SLs and the Marines want it so it won't get overlooked. The fact that they weren't done on the recent, successful sea trials will be because they already had enough work to do. SLs have been done, it's now (as you say) refining it for the UK's ships.
I was looking for a vid to show "RVL" (I know they're out there somewhere and I'm sure someone here knows where they are), but got distracted by this one because it's got lots of old Harrier and Lightning (EE, not LM) stuff. Takes a while to get to F-35, but right at the end there is a B landing whilst moving forward. Come to think of it, aircraft have been doing that for years, so it should be possible
.
https://m.youtube.com/watch?v=gUzJW71m6pw
Edited to add a quote from Engines...
I don't think that needs to be a concern as work has been undertaken on SLs and the Marines want it so it won't get overlooked. The fact that they weren't done on the recent, successful sea trials will be because they already had enough work to do. SLs have been done, it's now (as you say) refining it for the UK's ships.
I was looking for a vid to show "RVL" (I know they're out there somewhere and I'm sure someone here knows where they are), but got distracted by this one because it's got lots of old Harrier and Lightning (EE, not LM) stuff. Takes a while to get to F-35, but right at the end there is a B landing whilst moving forward. Come to think of it, aircraft have been doing that for years, so it should be possible
.https://m.youtube.com/watch?v=gUzJW71m6pw
Edited to add a quote from Engines...
Originally Posted by Engines
SRVL software - the aim of the programme was to use the existing flight control modes (and cockpit displays) as far as possible. Remember that SRVLs are a required manoeuvre for the USMC to short strips, and have been cleared for use in service. Work started on SRVL ship landing capability as far back as 2004, but the UK's indecision on F-35B/C procurement between 2010 and 2012 led to delays in the later stages of this work.
Last edited by Courtney Mil; 2nd Jun 2015 at 10:15. Reason: Add quote by Engines
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This post mainly for PhilipG, also others interested:
I might be able to help allay some of your concerns over SSLs - but I might not. Anyway, hope this helps.
The UK requirement for SSLs (SRVLs as were) has been taken extremely seriously by the JSFPO. As I know I've posted before, it arose in around 2003, and has been worked since, apart from the UK induced two year break from 2010 to 2012.
It might help to review how this has been addressed. There was an initial study in around 2003, mainly led by the LM/BAES flight controls. performance and flight test teams, plus ship suitability, to assess whether SSLs were possibly feasible on CVF, and whether any modifications might be required. These led on to initial simulator trials in the UK (around 2004) with early deck layouts for the CVF. Soon after the STOVL aircraft started short landing work to prove compliance with USMC short strip requirements, results were fed into the SSL models (simulations). The Qinetiq trials in 2007 and 2008 using the VVAC Harrier were designed to support SSL work, including landing aid design.
Meanwhile, the hard yards were being worked by the rest of the LM team, checking such aspects as landing gear response, braking performance, structural loads, flight control loads, pilot displays, engine control responses and tons of other stuff.
And the UK has developed a ground breaking new form of landing aid (the Bedford array) that is designed to exploit the F-35B's flight controls and displays to further reduce pilot workload in higher seas and bad visibility. Again, I don't expect anyone behind that work to get much credit on this forum, but they should.
I'm trying to get over the fact that this is a serious requirement, and is being worked as part of the overall programme. It's not a 'Dolittle' type measure, it's not being done 'half arsed' and it's not something terribly new - the aircraft already has to be able to do land based SLs, and is specifically designed to do them.
The key 'uncertainty' (to use your term - I'd use 'risk', but there you go) is putting the SSL manoeuvre into practice against a moving ship with the expected Wind Over Deck (WOD) - this means that the aircraft is moving faster through the air than relative to the deck. Clearly, this can't be tested on land. The main results that the ship trials would deliver would be the actual 'landing scatter' along and across the deck, as well as actual braking performance, as well as detailed routines for the people on the ship as well as in the aircraft to conduct these safely and effectively. This is normal, standard, well understood, ship integration stuff. It's not being done on a wing and a prayer.
Finally, I might be able to help with your concern over the ability of the F-35B to take off 'with a decent payload'. The programme had a KPP for a US flat deck STO and also a KPP for a UK ramp STO. (incidentally, this was the only UK specific KPP on the whole programme). This KPP assumed a set payload for a set mission. All the early data, later confirmed by flight test, was that the aircraft met this KPP with room to spare. Ski jump launches will, as expected, deliver safer and lower workload STOs at significantly higher weights than from a flat deck. As to whether these weights are 'decent' or not, I can't say. What I can say is that they are considerably higher than any catapult launched aircraft the UK ever put into the air, and exploit the F-35B's envelope to the full.
Hope this helps, best regards as ever to those actually doing the stuff for the people at the front line,
Engines
I might be able to help allay some of your concerns over SSLs - but I might not. Anyway, hope this helps.
The UK requirement for SSLs (SRVLs as were) has been taken extremely seriously by the JSFPO. As I know I've posted before, it arose in around 2003, and has been worked since, apart from the UK induced two year break from 2010 to 2012.
It might help to review how this has been addressed. There was an initial study in around 2003, mainly led by the LM/BAES flight controls. performance and flight test teams, plus ship suitability, to assess whether SSLs were possibly feasible on CVF, and whether any modifications might be required. These led on to initial simulator trials in the UK (around 2004) with early deck layouts for the CVF. Soon after the STOVL aircraft started short landing work to prove compliance with USMC short strip requirements, results were fed into the SSL models (simulations). The Qinetiq trials in 2007 and 2008 using the VVAC Harrier were designed to support SSL work, including landing aid design.
Meanwhile, the hard yards were being worked by the rest of the LM team, checking such aspects as landing gear response, braking performance, structural loads, flight control loads, pilot displays, engine control responses and tons of other stuff.
And the UK has developed a ground breaking new form of landing aid (the Bedford array) that is designed to exploit the F-35B's flight controls and displays to further reduce pilot workload in higher seas and bad visibility. Again, I don't expect anyone behind that work to get much credit on this forum, but they should.
I'm trying to get over the fact that this is a serious requirement, and is being worked as part of the overall programme. It's not a 'Dolittle' type measure, it's not being done 'half arsed' and it's not something terribly new - the aircraft already has to be able to do land based SLs, and is specifically designed to do them.
The key 'uncertainty' (to use your term - I'd use 'risk', but there you go) is putting the SSL manoeuvre into practice against a moving ship with the expected Wind Over Deck (WOD) - this means that the aircraft is moving faster through the air than relative to the deck. Clearly, this can't be tested on land. The main results that the ship trials would deliver would be the actual 'landing scatter' along and across the deck, as well as actual braking performance, as well as detailed routines for the people on the ship as well as in the aircraft to conduct these safely and effectively. This is normal, standard, well understood, ship integration stuff. It's not being done on a wing and a prayer.
Finally, I might be able to help with your concern over the ability of the F-35B to take off 'with a decent payload'. The programme had a KPP for a US flat deck STO and also a KPP for a UK ramp STO. (incidentally, this was the only UK specific KPP on the whole programme). This KPP assumed a set payload for a set mission. All the early data, later confirmed by flight test, was that the aircraft met this KPP with room to spare. Ski jump launches will, as expected, deliver safer and lower workload STOs at significantly higher weights than from a flat deck. As to whether these weights are 'decent' or not, I can't say. What I can say is that they are considerably higher than any catapult launched aircraft the UK ever put into the air, and exploit the F-35B's envelope to the full.
Hope this helps, best regards as ever to those actually doing the stuff for the people at the front line,
Engines
Last edited by Engines; 2nd Jun 2015 at 14:17.
What speed for a SSL?
Good stuff Engines.
Any idea what kinds of airspeeds are we talking about for a B doing a SSL at sea? Yes I get it could vary considerably with weights and conditions, but rough idea?
I imagine the QE class will be able to generate good wind over deck in most climates, and I was impressed with the short field landings I have witnessed up close with B's at Pax River. Perhaps a SSL would be a bit more sporting on a LHA/LHD (or Invincible), but looks like there is a good more room on a QE class.
Any idea what kinds of airspeeds are we talking about for a B doing a SSL at sea? Yes I get it could vary considerably with weights and conditions, but rough idea?
I imagine the QE class will be able to generate good wind over deck in most climates, and I was impressed with the short field landings I have witnessed up close with B's at Pax River. Perhaps a SSL would be a bit more sporting on a LHA/LHD (or Invincible), but looks like there is a good more room on a QE class.
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Sandie,
Having been so long out of the programme, any figure I gave would be a guess, but I think they're looking in the 55 to 70 knots airspeed region. Repeat warning - this is a guess. This would equate to somewhere around 30 to 45 knots deck speed, if the QEC can generate 25 kts WOD. Speeds would vary with assumptions/wind, ship speed, etc. As I remember, 45 kts WOD would be about the maximum for safe personnel ops on the deck.
I don't think an SSL would be cleared to an LHD deck, simply on account of the lateral safety margins required - unless they could clear the deck of aircraft, which is hard given their hangar capacity. Might be different on the larger LHA 'America' class deck, but probably still tight.
There should (in my view) be plenty of room on the QECs.
Standards have changed - an old friend of mine was a Sub Lieutenant Sea Vixen pilot flying off Hermes in the 1960s. Night deck landings gave a wingtip clearance of less than 15 feet from parked aircraft. In a Sea Vixen. Manual flying. At night.
I was just an engineer - God gave me c**p eyes, and in any case, I could never do what those people did back then. Huge respect.
Best Regards as ever to those who fly to the deck at night,
Engines
Having been so long out of the programme, any figure I gave would be a guess, but I think they're looking in the 55 to 70 knots airspeed region. Repeat warning - this is a guess. This would equate to somewhere around 30 to 45 knots deck speed, if the QEC can generate 25 kts WOD. Speeds would vary with assumptions/wind, ship speed, etc. As I remember, 45 kts WOD would be about the maximum for safe personnel ops on the deck.
I don't think an SSL would be cleared to an LHD deck, simply on account of the lateral safety margins required - unless they could clear the deck of aircraft, which is hard given their hangar capacity. Might be different on the larger LHA 'America' class deck, but probably still tight.
There should (in my view) be plenty of room on the QECs.
Standards have changed - an old friend of mine was a Sub Lieutenant Sea Vixen pilot flying off Hermes in the 1960s. Night deck landings gave a wingtip clearance of less than 15 feet from parked aircraft. In a Sea Vixen. Manual flying. At night.
I was just an engineer - God gave me c**p eyes, and in any case, I could never do what those people did back then. Huge respect.
Best Regards as ever to those who fly to the deck at night,
Engines
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Engines et al.
When the thoughts around an angled deck on the QECs to enable recovery with arrestor gear versus a 'through deck' design, was there the option to run a bastardised variant with an angled deck for SSL recovery and a through deck launch with a ski jump?
This would seem to offer the best of both worlds; however I am not blind to the fact that there would have been some other loss of capacity - even if this was a reduction of on-deck standing for the cabs.
I recall watching one of the ACA videos last year (?) showing some of the simulator work used to define the usable deck space.
No agenda - just thinking.
When the thoughts around an angled deck on the QECs to enable recovery with arrestor gear versus a 'through deck' design, was there the option to run a bastardised variant with an angled deck for SSL recovery and a through deck launch with a ski jump?
This would seem to offer the best of both worlds; however I am not blind to the fact that there would have been some other loss of capacity - even if this was a reduction of on-deck standing for the cabs.
I recall watching one of the ACA videos last year (?) showing some of the simulator work used to define the usable deck space.
No agenda - just thinking.
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This SLD article is worth a read ...
The New UK Aircraft Carrier: Reshaping the Royal Navy and the Royal Air Force | SLDInfo
Some will know that Group Captain P G is the RAF F-35 Desk Officer at the MOD.
The New UK Aircraft Carrier: Reshaping the Royal Navy and the Royal Air Force | SLDInfo
Some will know that Group Captain P G is the RAF F-35 Desk Officer at the MOD.
When the thoughts around an angled deck on the QECs to enable recovery with arrestor gear versus a 'through deck' design, was there the option to run a bastardised variant with an angled deck for SSL recovery and a through deck launch with a ski jump?
This would seem to offer the best of both worlds; however I am not blind to the fact that there would have been some other loss of capacity - even if this was a reduction of on-deck standing for the cabs.
This would seem to offer the best of both worlds; however I am not blind to the fact that there would have been some other loss of capacity - even if this was a reduction of on-deck standing for the cabs.
The point of an angled deck is to allow a CTOL recovery that misses the wires - a bolter - the ability to go around and try again. Happy to be corrected but I very much doubt whether an SRVL/SSL will be able to wind up sufficient thrust to do so. In which case the angle serves only to dump the cab over the side......