Turkey is a NATO country.
But probably not for much longer.
"Single point of failure"? Words, just words...
Britain’s F-35B fighter jets currently cost around $123m each – and British officials are quite content that the only engine overhaul facility for the stealth aircraft’s engines is located in Turkey. The House of Commons’ Defence Committee questioned British ministers, civil servants and senior officers on the F-35 purchase …
"it's just the only place in Europe the engines can be serviced"
I'm sure Turkey isn't the only place in Europe that has the technical capability to service the engines, especially as the front part of the VTOL system for the F-35B that the UK is buying was developed in the UK. In fact, Rolls-Royce developed an alternative engine for the F-35, but in the end the contract went to a US company.
This is purely a political move, in exactly the same way as putting the avionics refurbishment centre in North Wales was a political decision. The US needed other countries to buy the F-35 to increase the total number built, which would hopefully reduce the price down from "godawful" to merely "eye-watering", so as an inducement they farmed out lucrative repair contracts to various countries. The UK gets avionics, The Netherlands gets landing gear, Australia gets life-support etc.
This way the UK government gets happy defence contractors (always handy for the MoD worker looking for a comfy retirement gig), and safeguards a bunch of jobs somewhere that they'd like some more votes (lucky Sealand) and the RAF gets some planes. OK, maybe not the planes they wanted, but that's not really the politicians concern.
Having done some research it looks like Turkey is just the first place in Europe to build an engine overhaul facility, Norway and the Netherlands are due to have one each on line by ~2020 as well. There's an anticipated need for 3 overhaul lines in the Europe region and countries bid to host one, on the grounds that it's about a $1B investment for the country involved. So it's entirely possible we'll be shipping the engines across the North Sea rather than to Southern Europe.
I don't think there's anything to stop the UK doing all its overhaul work itself, except for the substantial investment involved.
I don't think there's anything to stop the UK doing all its overhaul work itself, except for the substantial investment involved.
...or that it might be a breech of the terms of the purchase contract.
Sure, the UK might have the technical ability to perform overhauls, but they might be missing the legal - contractual, patent licensing and copyright licenses - to do so. Not to mention possible software keys to also do so. For example, replacing a component on the engine might be detected by the engine firmware or aircraft flight/control systems, and might refuse to function until the appropriate license key is entered to show that it is an approved repair - a key only supplied to approved repairers like the Turkish.
That's not the way that works. Installed component removed, one drawn from spares reinstalled, then fly until all the gripes are signed off. Hopefully without injuring or killing someone along the way. Our local California Air National Guard unit [F-16's], and squadrons of Navy planes of all sorts to the south do it all the time. A bit of entertainment in my daily routine.
"The UK gets avionics, The Netherlands gets landing gear, Australia gets life-support etc."
It does rather sound like these aircraft are going to spend a significant amount of their service life being shuttled around the world for various service, repair and upgrades. I wonder how many hours of airframe life span will be "wasted"?
the problem is he's being an arsehole to people that are Turkish but he doesn't consider them to be his people.
If you haven't seen the footage of his 'bodyguards' beating the shit out of peaceful protesters including women in Washington DC it's a sight to behold and a reflection of the 'beat the fuckers up' approach he seems to take to everyone he sees as a dissenter.
https://www.youtube.com/watch?v=K7S2f-FwAf0
Calling Merkel a Nazi didn't exactly help his public relations persona....
He's another one of the 'rise of the demagogue' we seem to be seeing more and more these days.
Erdogan has Europe over a barrel on numerous fronts, the F-35 engines being one of the least important.
1) What Europe, you want to sanction me for becoming a tinpot islamist strongman? Hmmm, all of a sudden our refugee facilities are full and hundreds of thousands of Muslim refugees are streaming into the Balkans
2) What NATO? You want to cut down military procurement and cooperation with us? Well, it looks like there is a sudden increase in Russian ships being allowed through the Bosporus, and top-secret weapons data is finding is way to Moscow.
Etc., etc.
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'Can someone explain this to me? As I think he's talking shite.'
It's the airflow he's really talking about. As air is accelerated over various parts of the airframe, the upper surface of the wings, probably the canopy, the localised airflow reaches Mach 1 before the aircraft as a whole does. Hence the Transonic region which is something like M0.8 to M1.X*, why above M1.0, well the air is also slowed over some regions of the airframe so is still going subsonic when the aircraft isn't.
Early supersonic aircraft had more problems in the transonic region than the either side of it, although these days with area ruling it's less of a problem. With the F-35 I'd imagine the flight control system masks any issues from the pilot.
*Where I can't remember what X is typically.
Except the reports seem to be saying the handling turns to s**t around this range.
Which for what is a 4th (or 5th) Generation supersonic vehicle does not sound good.
Let me guess the RAF advice will be "don't get into situations where you fly at prolonged periods at transonic speeds "
'Except the reports seem to be saying the handling turns to s**t around this range.'
I haven't read the report although I recall it being a bit of an issue a few years back, however when the say the handling is degraded in the transonic region that may be from an engineers point of view, where it is but that doesn't prevent it being masked from the pilot. In the F-35 you move the controls and the aircraft figures out how to do what you've asked, there's no fighting with the stick to make the aircraft behave if you don't move it the flight control software will do its utmost to keep you pointing in the same direction.
Incidentally avoiding prolonged flight in the transonic region isn't a bad idea as drag reaches a peak before you become fully supersonic at around M1.2.
> Let me guess the RAF advice will be "don't get into situations where you fly at prolonged periods at transonic speeds "
Not sure that flying at trans sonic speeds has been a thing ever. Super sonic burns too much fuel and dogfights tend to happen below the trans sonic threshold.
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"The speed of sound in air is NOT dependent on pressure, only on temperature and composition of the air."
I refer you to wikipedia. it's dependent upon √ (dp/dρ). Although for an ideal gas, which expands isentropically, it only depends upon temperature, and for everyday use air doesn't depart enough from ideal to really worry about pressure.
"The speed of sound in air is NOT dependent on pressure, only on temperature and composition of the air."
Not entirely true. If the air pressure and hence density is so low that gas molecules have little chance of hitting each other and hence passing on sound waves then the speed of sound is close to or at zero.
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Not entirely true. If the air pressure and hence density is so low that gas molecules have little chance of hitting each other and hence passing on sound waves then the speed of sound is close to or at zero.
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No, that does not affect the speed of sound at all, it affects how much the sound is *attenuated* over a given distance. At infinite attenuation (e.g. a vacuum) there is no sound at all and therefore its speed is meaningless.
@boltar "Not entirely true. If the air pressure and hence density is so low that gas molecules have little chance of hitting each other and hence passing on sound waves then the speed of sound is close to or at zero."
To put flesh on what Cynic_999 says, the speed of sound in the interstellar medium is around 1000m/s (at 100K), about three times faster than the speed of sound through air at ground level on earth. And it gets faster the hotter the medium gets.
The speed of sound in a gas varies with temperature, hardly with pressure (there is a slight variation since gases are not Ideal). It also varies depending on the gas -- the speed of sound is a lot higher in hydrogen at room temperature than air (1270m/s vs. 330m/s). The interstellar medium is mostly hydrogen, I believe so even if it's a lot cooler than Earth's biosphere then the speed of sound will still be a lot higher higher than in air at STP.
The guns with the highest muzzle velocity use hot hydrogen behind the projectiles since the speed of sound is the limiting factor determining the final muzzle velocity (i.e. the speed of the pressure pulse behind the projectile).
"the speed of sound in the interstellar medium is around 1000m/s (at 100K)"
The speed of sound of typical air at normal temperature (some 25C, or 300K) on Earth is some 300m/s. The speed of sound in the interstellar medium will be much higher despite the low temperature because the medium consists mostly of hydrogen gas and the speed definitely changes with the molecular mass. If you want to verify that last bit, inhale some helium and try to give your best Dearth Vader impression.
"Not entirely true. If the air pressure and hence density is so low that gas molecules have little chance of hitting each other and hence passing on sound waves then the speed of sound is close to or at zero."
If the wings fall off no one can hear you scream, then again; who needs wings in outer space?
For those with an hour to spare, this is an interesting lecture by Dr. Holger Babinsky, Cambridge University Engineering Department: "Common misconceptions on lift"
https://www.youtube.com/watch?v=XWdNEGr53Gw
"pressure is a factor of temperature and composition"
Not only. The number of molecules of a fluid in a given space - ie density - matters. Why do you think the pressure under water rises so much quicker than in the atmosphere? The temperature is similar and water molecules are lighter than N2 or O2 molecules which make up most of the atmosphere.
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The speed of sound is dependant upon air pressure, so it changes by altitude. Most of the time the tip of the stabiliser is higher in the sky than the belly of the aircraft.
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The speed of sound is not in fact affected by air pressure - but it is affected significantly by temperature.
The parts of the aircraft that are facing the airflow (nosecone, leading edges of wings & tail) have a huge increase in pressure - but as said this is not the thing that directly affects the speed of sound. What does affect it is the fact that when you compress air that much in a fraction of a second it heats up. A lot. Then there's frictional heating as the air passes over the skin of the aircraft, which at supersonic speeds in not inconsiderable.
The higher the temperature, the faster the speed of sound.
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Yes and no - the plane is travelling at the same speed, but the relative speed of the air hitting it may be different.
For example take the SR-71 Blackbird. It has adjustable cones on the front of it's engines, which are used to deflect the air at supersonic speeds away from the engine intakes so the air that does come in is moving subsonically and doesn't destroy the engines.
This is also true of Concorde, which uses flaps in the engine intakes instead.
Can someone explain this to me? As I think he's talking shite.
He is not. Basic aerodynamics - the airflow above the wing is faster than the airflow under the wing. There are a few other places where you get similar picture - air intake, etc.
The control problem is related - most modern fighter aircraft rotate a whole "fin" in the tail or a whole canard (not a flap on its end) for control purposes. That immediately creates or alters a subsonic on one side, supersonic on the other side airflow situation. The fact that the aircraft is inherently unstable as all stealth fighters adds insult to injury and you are in a position where you start praying to the mother of the programmer who wrote the flight control software. Or swearing at her.