F-35 Cancelled, then what ?
I wonder why the US Navy and USMC have studiously avoided any form of ramp for their amphibious carriers. I've read several reasons such as a ramp affects the ships handing or the loss of deck space is unacceptable etc. Surely some bright spark could come up with a portable ramp that can be dropped/moved once the Harriers/F-35s have launched?
Because the 30+ m of ramp doesn't just lose number 1 spot, it hems in the aircraft deck park forward, see phot for details. On a ship with 33m beam at the flightdeck, losing half that forward for a ramp means chaos for the handlers.
A moveable ramp that'll support a 25te cab with an entry speed of 80kts or so and remain reliable and bug-free when subjected to salt-water, being goffered, and little or no maintenance will not be cheap or simple.
Originally Posted by evansb
Such a complex and expensive solution to such a primitive question, i.e. to blow up the enemy. Such a curious, insatiable and violent species we humans are. Oh well..
Oh thank you Evans for saving me.
Do a Hover - it avoids G
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Interesting point that you mentioned about pitch rate at ramp exit.
The fact that the ramp induces a pitch rate on the aircraft really made me lose the plot when I was first asked my opinion about Doug Taylor’s idea for a ramp take off for the Harrier back in 1976. I had just walked into my office after a couple of weeks with the USMC watching them fly from an LPD. On several of their STOs the pilots had the stick pinned on the forward stop for a couple of seconds trying to control a pitch-up as they entered the upflow of air that is ahead of any ship’s bow (which was increasing their AoA). So when the Kingston performance man rang me up to tell me about this ramp idea, the poor (good) bloke got the full benefit of my jetlag plus a real earfull about adding pitch rate to an aircraft which already had inadequate controllability off a flat deck.
However the next day after a bit of thought it was clear there were many advantages to the ramp idea if we improved longitudinal control. In the event further thought made it clear that after the nose wheel left the ramp the aircraft had a split second or two with the main wheels still on the ramp and pushing like mad up behind the CG. A couple of sums suggested this effect would just zero the ramp induced pitch rate on the aircraft. Since there is an aeronautical god that is indeed how it worked out. Bottom line – higher weights and higher speeds did not give (Harrier) greater pitch rates at launch, because as speed increased up the ramp the g also increased and in turn increased the nose down moment in play after the nose wheel left the ramp.
Clearly for any given type the issue is gear position/CG position/longit inertia related but the sums are not rocket science. Dunno about the B but I am sure plenty do.
so the exit speed will be low, giving a low pitch rate at exit
The fact that the ramp induces a pitch rate on the aircraft really made me lose the plot when I was first asked my opinion about Doug Taylor’s idea for a ramp take off for the Harrier back in 1976. I had just walked into my office after a couple of weeks with the USMC watching them fly from an LPD. On several of their STOs the pilots had the stick pinned on the forward stop for a couple of seconds trying to control a pitch-up as they entered the upflow of air that is ahead of any ship’s bow (which was increasing their AoA). So when the Kingston performance man rang me up to tell me about this ramp idea, the poor (good) bloke got the full benefit of my jetlag plus a real earfull about adding pitch rate to an aircraft which already had inadequate controllability off a flat deck.
However the next day after a bit of thought it was clear there were many advantages to the ramp idea if we improved longitudinal control. In the event further thought made it clear that after the nose wheel left the ramp the aircraft had a split second or two with the main wheels still on the ramp and pushing like mad up behind the CG. A couple of sums suggested this effect would just zero the ramp induced pitch rate on the aircraft. Since there is an aeronautical god that is indeed how it worked out. Bottom line – higher weights and higher speeds did not give (Harrier) greater pitch rates at launch, because as speed increased up the ramp the g also increased and in turn increased the nose down moment in play after the nose wheel left the ramp.
Clearly for any given type the issue is gear position/CG position/longit inertia related but the sums are not rocket science. Dunno about the B but I am sure plenty do.
Another dumb question: what would make a ski jump/ramp (a longer gentler one) not work for a larger aircraft e.g. length of an a380 roughly?
I admit it's straying offtopic but there is a reason for asking. I'm thinking of a huge vehicle which needs a 5.5km long, reinforced runway to take off and I'm wondering if e.g. a jump of some kind might make that runway 1/5 less expensive to build (assuming the jump itself wasn't inordinately expensive to build). The normal takeoff speed would be m0.5. My very dodgy arithmetic says the thrust/weight ratio would be about 0.26 at sea level.
I imagine there are other considerations like extra space for aborting or whatever that might make it all pointless but I'm interested most in just whether it's ridiculous (of course it is) and roughly why.
I admit it's straying offtopic but there is a reason for asking. I'm thinking of a huge vehicle which needs a 5.5km long, reinforced runway to take off and I'm wondering if e.g. a jump of some kind might make that runway 1/5 less expensive to build (assuming the jump itself wasn't inordinately expensive to build). The normal takeoff speed would be m0.5. My very dodgy arithmetic says the thrust/weight ratio would be about 0.26 at sea level.
I imagine there are other considerations like extra space for aborting or whatever that might make it all pointless but I'm interested most in just whether it's ridiculous (of course it is) and roughly why.
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There would be no theoretical problem to scaling the ramp principle. The practical issues of a large size one are another matter obviously.
However to obtain any real benefit in respect of reduced take off distance when using a ramp you need two things:
1 A flight control system that enables attitude control at speeds well below the normal aerodynamic stall for the aircraft concerned.
2 A minimum thrust weight ratio of around .85 to .9 so that during the limited flight time the ramp gives you (when lift is less than weight) you can accelerate quickly to where the wings alone will let you fly before your vehicle subsides back to the ground.
Sorry – a T/W of .25 would rule out any real advantage
However to obtain any real benefit in respect of reduced take off distance when using a ramp you need two things:
1 A flight control system that enables attitude control at speeds well below the normal aerodynamic stall for the aircraft concerned.
2 A minimum thrust weight ratio of around .85 to .9 so that during the limited flight time the ramp gives you (when lift is less than weight) you can accelerate quickly to where the wings alone will let you fly before your vehicle subsides back to the ground.
Sorry – a T/W of .25 would rule out any real advantage
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First, as a Swede, I emphatically encourage everyone to get at least one JAS Gripen. That would be The Best!
Second, I have seen some news about this giant dropped ball that is F-35. Last programme was from Fifth Estate (Canadian). Why are y'all keep funding something that might pan out in 30 years or so, when we already had wonderful, brilliant innovations like the B-2, the Blackbird and Nimrod to name just a few amazing aircraft.
It feels like someone is trying to re-invent the wheel but failing miserably.
Oh and BTW, get a Gripen!
Second, I have seen some news about this giant dropped ball that is F-35. Last programme was from Fifth Estate (Canadian). Why are y'all keep funding something that might pan out in 30 years or so, when we already had wonderful, brilliant innovations like the B-2, the Blackbird and Nimrod to name just a few amazing aircraft.
It feels like someone is trying to re-invent the wheel but failing miserably.
Oh and BTW, get a Gripen!
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t43562: ......a huge vehicle which needs a 5.5km long, reinforced runway to take off and I'm wondering if e.g. a jump of some kind might make that runway 1/5 less expensive to build.....
.......So good application for non-catapult equipped aircraft carriers, and perhaps a one off very heavy aircraft like a single stage to orbit arcraft, but limited utilty for say an airliner.
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Coffman
You could have as much vodka as you'd need in a lifetime if it was up to me!
The Gripen (translation: Griffin) is really an amazing airplane for European needs. I am sad that the US bribed Norway to buy their plane instead - that was a stab in the back from our dear neighbour. US always want huge planes - Europe is so condensed we really don't have use for them unless we need to go to Mongolia for whatever reason. Oh well, I could talk for hours about this...
draken55
Those are some beautiful pictures! Glad to see someone outside Sweden knows JAS Gripen exists!
One more fantastic airplane I forgot in my list of wonderful innovative and truly special planes I think we could rebuild and retrofit (no need to reinvent the wheel methinks) is the Harrier. Apparently hard to fly (obviously I have only seen those on TV) but an amazing feat of engineering and sadly underestimated. The VTOL is just mindblowing, really. British aerospace companies did a fantastic job in developing the Harrier! (And the Vulcan: a beauty with a horrifying sound, I would be scared ****less just from the howl itself...)
Aaaaanyway, this would be the end of my threadjack. The F-35 is a big clunk of expensive mess that I wonder what it is trying to achieve. Usually when you want it all, you end up with a pile of garbage. I thought this lesson had been learned already but I must have misunderstood things.
You could have as much vodka as you'd need in a lifetime if it was up to me!
The Gripen (translation: Griffin) is really an amazing airplane for European needs. I am sad that the US bribed Norway to buy their plane instead - that was a stab in the back from our dear neighbour. US always want huge planes - Europe is so condensed we really don't have use for them unless we need to go to Mongolia for whatever reason. Oh well, I could talk for hours about this... draken55
Those are some beautiful pictures! Glad to see someone outside Sweden knows JAS Gripen exists!
One more fantastic airplane I forgot in my list of wonderful innovative and truly special planes I think we could rebuild and retrofit (no need to reinvent the wheel methinks) is the Harrier. Apparently hard to fly (obviously I have only seen those on TV) but an amazing feat of engineering and sadly underestimated. The VTOL is just mindblowing, really. British aerospace companies did a fantastic job in developing the Harrier! (And the Vulcan: a beauty with a horrifying sound, I would be scared ****less just from the howl itself...)
Aaaaanyway, this would be the end of my threadjack. The F-35 is a big clunk of expensive mess that I wonder what it is trying to achieve. Usually when you want it all, you end up with a pile of garbage. I thought this lesson had been learned already but I must have misunderstood things.
LJ
I agree Mr S.
I think your product will sell more and more over the coming decade.
A lot of countries cannot afford F-35 (or Typhoon) and there are very few alternatives in the west - Rafale or Gripen.
I somehow think that Rafale will not sell that well after this current blip of orders.
It is a shame many countries are not forward looking enough to see what they will end up buying, band together and drive the price of Gripen down.
I find Boeing looking at offering a lite version of Gripen for the TX contract very interesting. If it did come to fruition could anyone imagine ANG F-16s being replaced by a US built Gripens rather than F-35?
I think your product will sell more and more over the coming decade.
A lot of countries cannot afford F-35 (or Typhoon) and there are very few alternatives in the west - Rafale or Gripen.
I somehow think that Rafale will not sell that well after this current blip of orders.
It is a shame many countries are not forward looking enough to see what they will end up buying, band together and drive the price of Gripen down.
I find Boeing looking at offering a lite version of Gripen for the TX contract very interesting. If it did come to fruition could anyone imagine ANG F-16s being replaced by a US built Gripens rather than F-35?
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F-35 Unscathed by Hostile Fire in Green Flag, says Aviation Week.
Not a single F-35 was “shot down” during the joint-force Green Flag exercises testing the jet and its pilots’ prowess operating it in a contested air-support role in the Western U.S. this month, according to U.S. Air Force Lt. Col. Cameron Dadgar, head of the exercise and leader of the 549th Combat Training Sqdn. at Nellis AFB, Nevada. This is notable because A-10s and F-16s were defeated in the same conditions, operating in an environment with hostile aircraft, just another rumour to mull over.
Not a single F-35 was “shot down” during the joint-force Green Flag exercises testing the jet and its pilots’ prowess operating it in a contested air-support role in the Western U.S. this month, according to U.S. Air Force Lt. Col. Cameron Dadgar, head of the exercise and leader of the 549th Combat Training Sqdn. at Nellis AFB, Nevada. This is notable because A-10s and F-16s were defeated in the same conditions, operating in an environment with hostile aircraft, just another rumour to mull over.
According to Russia's Western Military District spokesman, Col. Oleg Kochetkov, the district will receive an unspecified number of advanced S-400 Triumf and Pantsir-S air defense systems by the end of 2015.
Read more: Russia to Deploy S-400 Air Defense Systems Near Western Borders by End 2015 / Sputnik International
USMC IOC mid 2015?
Well what’s the betting ^they^ go nowhere near any kind of "threat"?
Cue "those in the know"
that operating the USMC F35B in such an environment is outwith the initial IOC parameters as [insert BS line here] and unrepresentative bla,bla...
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But we agree, don't we, that legacy fighters cannot exist in the threat environment currently fielded. So I assume all F-35 knockers are also content that manned aircraft are no longer viable on the high end battlefield?
As drones haven't made anywhere near the impact they were supposed to - it seems they've done the straight forward long persistence stuff but not anything requiring high performance or high end weaponry, one assumes that the SAM has won full stop.
Not to worry. AT and ISTAR should keep us busy enough. Potentially SH as well but the cushion layer is certainly getting more fruity as time goes by.
As drones haven't made anywhere near the impact they were supposed to - it seems they've done the straight forward long persistence stuff but not anything requiring high performance or high end weaponry, one assumes that the SAM has won full stop.
Not to worry. AT and ISTAR should keep us busy enough. Potentially SH as well but the cushion layer is certainly getting more fruity as time goes by.