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F-35 Cancelled, then what ?

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F-35 Cancelled, then what ?

Old 24th Jun 2015, 13:11
  #6341 (permalink)  

Do a Hover - it avoids G
 
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Engines

so the exit speed will be low, giving a low pitch rate at exit
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.
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Old 24th Jun 2015, 17:27
  #6342 (permalink)  
 
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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.
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Old 24th Jun 2015, 18:13
  #6343 (permalink)  
 
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It may well work, t43562. But I have to ask an equally numb question. Why would we need to do that?
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Old 24th Jun 2015, 18:48
  #6344 (permalink)  

Do a Hover - it avoids G
 
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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
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Old 24th Jun 2015, 20:43
  #6345 (permalink)  
 
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Many, many thanks :-) I was sure it was not sensible but it's very unsatisfying to have no idea of why. I was thinking of the Skylon single stage to orbit vehicle.
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Old 25th Jun 2015, 21:35
  #6346 (permalink)  
 
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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!

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Old 25th Jun 2015, 22:02
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If you throw in a couple of cases of Swedish Vodka ... You could have a deal
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Old 25th Jun 2015, 22:03
  #6348 (permalink)  
 
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MrSnuggles

We do have a Gripen!

http://www.etps.qinetiq.com/school/fleet
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Old 26th Jun 2015, 13:19
  #6349 (permalink)  
 
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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.....
Also remember that aircraft needs a place to land, so you still need a longish runway. And you usually want to take off into the wind, so you would need multiple ski jumps. And you dont want a ski jump in the middle of your landing run .......

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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Old 26th Jun 2015, 18:34
  #6350 (permalink)  
 
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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 shitless 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.
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Old 26th Jun 2015, 21:53
  #6351 (permalink)  
 
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So good application for non-catapult equipped aircraft carriers
Also handy when your runway can be tuned into the wind
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Old 26th Jun 2015, 21:58
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MrSnuggles

We do have a Gripen!

http://www.etps.qinetiq.com/school/fleet
Particularly enjoyed the picture of the Tornado F3 on the ETPS website labelled Tornado GR4!!!

LJ
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Old 27th Jun 2015, 00:09
  #6353 (permalink)  
 
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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?
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Old 27th Jun 2015, 07:48
  #6354 (permalink)  
 
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That must be almost the best reason to go to ETPS - fly a float plane...........OK, just dreamimg
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Old 27th Jun 2015, 10:13
  #6355 (permalink)  
 
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Originally Posted by KPax View Post
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.
Have another one.

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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Old 27th Jun 2015, 12:56
  #6356 (permalink)  
 
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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.
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Old 27th Jun 2015, 12:58
  #6357 (permalink)  
 
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Wouldn't be interesting if Boeing acquired Saab AB? Keeps their fingers in the fighter market once the F-18 line closes, and bridges to the F/A-XX competition.
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Old 27th Jun 2015, 18:24
  #6358 (permalink)  
 
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Originally Posted by orca View Post
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.
orca, believe whatever you want.
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Old 27th Jun 2015, 18:43
  #6359 (permalink)  
 
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Then what? Buy Indian, obviously! Just hope it has better build quality than a Royal Enfield!


Skijump and traps is all that is required and BAESYSTEMS already have a deal with HAL who make the LCA Tejas as seen in the video.

Simples...

LJ
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Old 27th Jun 2015, 21:11
  #6360 (permalink)  
 
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Impressive Leon.
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