SchorschSyria has a problem. It has to give away the site and nature of it to claim something. Not in Syrias intrest, when something secret is to hide to the public. The impotence of own AD is nothing to highlight too.
The best way to bail out from that is to downplay that incident and call it a failure.
Israel gives not away the details for good reasons. Such an action does involve three other parties at least. Turkey, Iraq and USA. Non has any intrest to be related to that. It was a high risc operation in some way.
Israel does operate F-15, F-16, C-130, Ch-53, S-70s like the USA and Turkey. So such type of aircraft landing in Turkey or Iraq will not rise suspicion. To glue some folie about the insignia temporary is enough to hide the true identity.
Why is Iraq involved? Do you want to indicate that special forces used Iraq as launch base, or that Israeli aircraft ingressed via Iraq? For both scenarios the way in and out of Iraq is not easy. Thinkable is that transport aircraft brought helicopters to Iraq via normal air routes.
SchorschOkay how about this:
– A light transport, optimized for mid-range subsonic cruise
– the airplane uses several conventional high lift wings in order to generate extra lift and decelerate during the final approach.
– the main engines or extra lift fans are used for extra lift (possibly using various innovations to trade efficiency for a temporary increase in thrust lasting around fifteen to thirty seconds), this is combined with an unconventional (thrust vectoring or vaned) control system to maintain control at low speeds.
– The landing approaches are calculated by several small millimeter wave length radars and is automated (possibly with a lead craft in front to check atmospheric conditions) allowing very accurate high speed approach vertical landings.Use:
– The airplane takes off conventionally, lowers weight through fuel consumption, bleeds speed/altitude conventionally, uses lift engines (fan or vectoring) for the final landing. This allows almost vertical landing.
– The main cargo is detached and left behind (the aircraft is now light and can take off vertically), the aircraft returns.
– Then when the work is done, the aircraft arrives and lands vertically, picks up personnel and expensive equipment and then uses extra lift devices to get this much lighter cargo airborne and bring it home.A sort of CTOVLVTOCLCTOVLVTOCL system.
Feasible in eighty years?
The problem is that subsonic flight (up to M0.7) at low level and short landing/take-off nearly cancel each other out. I would really on totally oversized engines with high bypass ratio, able to rotate a bit. Blow flaps to assist. Principally the same as done before, just using modern technology where appropriate and scaling down requirements so that headache becomes controllable.
Still I think if an USAF general would make the requirements, we would have the high-speed, low-level, vertical take-off transonic stealthy combat zone transporter. And it would get cancelled by Congress when elected people see the bill.
SchorschAh! We have exposed the semi-knowledgeable.
Examine the F-18’s wing and you will find it’s sole grace is low landing speed for operation in the CV’s landing pattern. NAVAIR’s demand for a 130 kias approach speed forces the designer into some serious compromises that effects performance that would be useful in other portions of the flight envelope. To create lift at low speed, the designer has to either increase wing area, increase CL by blowing, or increase span. F-18 designers chose to increase span.
Increased span forced the designers to make other compromises to wing design. While a swept wing with a 40 degree leading edge is an excellent compromise for all areas of the flight envelope, F-18 designers chose what is essentially a straight wing. Despite the lack of sweep, a tooth was added at the wing fold because they couldn’t stand a tiny amount of spanwise flow. The most serious design issue is decreasing wing thickness in an effort to improve transonic performance. Aeroelastic problems occur as too thin of a structural box results in a twist around the Y axis (aileron reversal) if the ailerons are deflected any significant amount.
So, what does the F-18 have? A straight, structurally weak, high drag, long span wing with high rolling inertia that is great for landing on the CV, but does nothing else well.
Fortunately, the guys in St. Louis learned from their mistake and corrected the wing design for X-45, before it was canceled.
So, first of all you say that the F-18E/F is based on fishy requirements, don’t you?
But let’s see the numbers first:
F-18C
Wing area: 400ft²; 38m²
Span: 12.3m
Aspect Ratio: 3.98
F-18E
Wing area: 500ft²; 46m²
Span: 13.6m
Aspect Ratio: 4.02
The Super Hornet retains the exact similar relationship between wing area and wing span.
But generally your description is quite accurate, the problem with wing rock and its solution well known to the more knowledgable people in this topic. I guess it was 5 to 12 for the SuperHornet to get a wing fence, but the saw tooth and a new flap-slat schedule addressed the problem to satisfaction. Interestingly, the F-18A was also originally planned with saw tooth.
In conclusion: The F-18E/F is affected by engineering problems like many, or better all, fighter designs in the world. Many of these problems have ther origin in requirements, some of those make sense, some not. It doesn’t make the aircraft particularly bad.
Schorschwhich “half-a-billion” bomber are you referring to?
The Tu-160 would be – well put – such a machine. On American terms, the B-1B can called a half-a-billion bomber. The B-2 is called the billion-dollar-bomber. Actually, substracting development costs, the B-1 lands close to 250 million and the B-2 lands at 700 million. That is without inflation correction, so in 19xx USD. Quite hard to figure.
SchorschErm….
Well, lets see.
Did Iraq require strategic bombers? Yeap.
Did Afghanistan? Yeap
Did Kosovo? Yeap
Did Iraq 1? Yeap
Uhm… 🙂
EDIT: OK, maybe the word REQUIRE is misplaced, but they were used.
Did Iraq require a supersonic, swing-wing, low-level but still not stealthy half-a-billion bomber?
Nope
Did Afghanistan require a supersonic, swing-wing, low-level but still not stealthy half-a-billion bomber?
Nope.
Did Kosovo require a supersonic, swing-wing, low-level but still not stealthy half-a-billion bomber?
Nope.
Did Iraq1 require a supersonic, swing-wing, low-level but still not stealthy half-a-billion bomber?
Nope.
SchorschFor Russia this is not 2814ff, this is a big ego thingy.
Unfortunate. Other nations like to win in soccer for that purpose. Less predictable, but generally less costly and more sustainable.
SchorschYC-14 (although it ain’t exactly small)
Had the same idea. Some downscaling, it was supposed to carry a tank. I guess a 10000lb payload and 700nm radius for a STOL mission sufficies.
SchorschVery interesting. I am sure two lift fans in PW 135s weigh much less than the eight lift jets, which are dead weight in forward flight. There will also be a lot less drag using PW 135 engines. But I am surprised that the Do 31 worked as well as it did with 1967 technology.
And I guess people realized that the whole undertaking was a death-born child.
Unfortunately, your proposal is one, too. “Supersonic stealthy combat zone transporter” sounds like multi-billion waste-bin.
One could talk about a vertical or extremely short-land aircraft with high useful speeds and good low level flying, something like a down-scaled A400M.
You’ll always find a 1000ft strip somewhere in target vicinity. With latest turbo-fan engines, a good high-lift equipped wing and reduced payload you’ll get in there.
SchorschThe SuperHornet excels any other aircraft design in provoking discussions absolutely free of knowledge or insight in fighter aircraft performance, either requirements or actually tested. It leads to people writing posts with contents like “crappy wing” or “terrible aircraft”, which just don’t suite these people well. It always implies that pure idiocity was at work when the aircraft was designed.
Attached to these discussions is the nearly similar BS-based claims on the global superiority of the F-14. It gets really funny if someone actually tries this with technical figures, just to fail and embarass himself (as, using accepted performance criterias, the F-14 even loses against an F-4 Phantom).
I myself find the SuperHornet entertaining. It also helps to find out where people truly stand in terms of background knowledge.
SchorschWhat do they need strategic bombers for?
Is really anybody else fed up with money, so they can attack priority list item number 2814?
SchorschAnd there is the problem if factors like drag etc are the same, but that is unlikely for different designs. I know the breguets equation takes all the factors into account, but for me it sounds like you limit it to the fuel fraction only and this is simply not true.
The “mission profiles” were just mentioned to underline that these are important and as the range figures I mentioned aren’t brought in conjunction with specific mission profiles etc. I can’t say how big the difference would be with the same profiles, assuming different profiles formed the base for the numbers.
Trying to evaluate the range of to different aircraft with fuel fraction alone and assuming that all other factors are equal won’t relfect reality.
You assertions are basically right. But in this case we compare two fighters with comparable drag characteristics and similar engines. Although propulsion integration is slightly different, it doesn’t count much when most of the mission is subsonic.
Mission profile is climb cruise combat climb cruise descent. Like shown below. See that actual combat is not part of the radius. The elegant F-4 below has a 5000lbs allowance for combat. The centerline tanks goes just for take-off and climb.
I don’t limit my considerations to fuel fractions, but when I ask for a combat radius I always assume a sample counter air mission for a fighter aircraft or high-low-high mission for an attack aircraft. An F-16A will have two combat radii, namely the counter-air with 2 tanks and 4 sidewinder, while the attack mission would be 2 tanks, 2 bombs and 2 sidewinder.
When the air combat is taken away in the sample mission below, the range would increase to ~1400nm, taken away reserves we will land somewhere close to 1600nm (=2960km), which is still a bit shy of the 3180km given by the German Air Force. Which is actually a good rule or thumb: for combat range divide “range” by three.
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Comparable:
http://www.f20a.com/f20airsupmission.jpg
http://www.f20a.com/f20casmission.jpg
http://www.f20a.com/f20capmission.jpg
http://www.f20a.com/f20interdictmission.jpg
SchorschThe most severe drag at subsonic speeds is frontal drag. When it comes to external tanks, there is no linear affair between drag and fuel content.
Switching to 600 gal ETs will not bring a similar rise in drag. By that they are more fuel efficient than ETs with lower contend. The thumb-rule, that ETs do consume half of their content to overcome the related drag is no longer true. Fast packs are close to the optimum, when true subsonic flown.
I would guess from my data that a pair of external tanks increases zero-lift drag by about 10 to 20%. Add to that the lift induced drag due to additional weight. When the aircraft cruises at optimum subsonic speed, the fuel flow increases likewise 10 to 20%. Supersonic speeds or transonic maneuvering is no wise idea with external tanks, at least when not specifically designed for it. Supersonic tanks increase fuel flow by about 20 to 30% for similar speed, lift-induced drag does not really count here.
FAST packs of CFT in general have the disadvantage of being with the aircraft all the time. More an option for strike aircraft.
The fuel-fraction is linked to the fuel-consumption of the engine and its digital control. Add to that an smart FBW for most drag-free flight (minimum trim drag at high weights!)
Just to give a first idea about that. Thumbrules from the 50s-70s are no longer true, when not related to the same technology.
That’s true, using fuel fraction for dissimilar aircraft will not yield any useful results. It also loses significance for transonic flight (beyond M0.85 for fighters) or supersonic flight. But for subsonic flight, which makes the combat radius, it can also be applied for modern aircraft. Information about SFC and glide ratio is hard to obtain for fighter modern, but if one is trying hard, he might some day get lucky. 😀
SchorschI have heared about it. But the range is in the end a combination of fuel consumption, load, weight and thrust. You have to take into account all these factors to get the range. The fuel fraction alone doesn’t bring you results.
You should increase your knowledge before coming up with those statements. With Wikipedia and Google you can make yourself an expert within 30 minutes. The Brueget equation considers all basic factors.
Fuel fraction will tell you the range, especially if some parameters are similar or the same (drag, engine). Of course, we can discuss about mission profiles, but for a comparison these are the same.
SchorschNot likely. A lot of F-16s are going to get shot down by SARH missiles before they have a chance to engage. The F-16 has an advantage close in, but not a really big advantage. F-15 turning performance is a close second to the F-16. In the early days, if the weather is really bad, an F-15 in the muck could hurl Sparrows at the F-16 and the F-16 won’t even have a target to shoot back at. And if you don’t find me persuasive, I have been told by an F-16C pilot that the F-15 is the better fighter.
As Sens said, the scenario always was Middle European hostilities. Real hostilities would more or less restrict fights to low to medium level, lots of ECM, probably problems with identification.
A stupid F-16 squad would run into the F-15 straight on, bringing the opponents weapons to maximum effect. The well trained and tactically skilled pilot will use his aircraft’s capability to his best use. Always consider: The F-16 would engage most likely in superior numbers, considering higher sortie rates and its lower price.
The F-16 can detect an F-15 before it can launch its Sparrow. It will know when being shot at. Just make an Immelmann and fly straight in different direction for 30 seconds and the missile will miss due to lack of range.
SchorschFuel fraction alone isn’t decisive for the range at all. It is one important factor to consider, but not the only one.
What else would you suggest to use?
Have you ever heard of Brueget range equation?
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