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(necro)What speed do SAMs travel at? Any aircraft that can outrun?

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Those of you who talk up the F-16 must have no first-hand knowledge of them. In the Air Force, they are kindly referred to as "lawn-darts". Lose the single engine, and there is no gliding to safety. If it wasn't for ejection seats, they would be a highly unpopular item in the Air Force arsenal because far too many pilots would have been lost by now. As it is, they are favored because they are cheap, requiring only one engine instead of two. The reliance on a single engine is it's main weakness. Just about all of our fighter's since the F-4's during the Vietnam Era have essentially been flying bricks. Without the thrust of at least one engine, they have very little glide capability. The F-15's and 18's have two engines which gives the aircraft greater survivability in the event of a single engine failure. In an F-16, ejection is your only option. Compare the number of crashes of F-16's to other models, and you'll see what I mean.

If you want to talk about wasting money, look up the MV-22 Osprey. Not only has it been a huge waste of money, but it is still unable to do what it was advertised to be able to do. It's range and payload capacity (main selling points) have been greatly diminished from what was promised. During rapid insertion and extraction operations, the propwash is too severe to conduct operations in the way it is currently done with helicopters, and there are many more difficulties. But we are still buying them. It's funny that all the Marines wanted were newer/better helicopters to replace their aging models, and the politicians essentially forced them to take the Osprey because it would pump more money into their states. While they are still trying to work the bugs out of the Osprey at great expense, the Marines of today are flying helicopters flown by their fathers in Vietnam.
 
Their submarine tech was also quite advanced for the time. In fact, it was SO advanced, the Russians essentialy made carbon copies of the Type XXI U-Boat for decades after the war that NATO would designate the "Whiskey" and "Zulu" classes.
Click to expand...

As indicative of how far behind the Russians were as anything else... they also copied the B-29 and British jet engines (they were behind on a lot of things). The real German innovation was the propulsion system, which the Americans and Brits also copied, iirc. On the other hand, the Germans were behind in sonar and radar technology which is why their subs were being slaughtered (and were basically retired) towards the end of the war.

And I wouldn't say their atomic research was "WAY" behind - given another 5 years, they would have had one.
Click to expand...

They were pretty far behind, it's debatable that they would've figured out the 'how' in five years, a near-certainty that they would not have had the resources. It's been suggested that Heisenberg deliberately sabotaged the German A bomb effort. Even accepting that they were only five years behind... five years is an eternity considering the war only lasted six years (in Europe anyway).
 
Apparently the experimental German reactor had rather dubious safety devices- in the case of supercriticality that couldnt be controlled, someone had to run to a room, open a locker, take out a lump of.... cadmium I think, and chuck it into the reactor by hand. Presumably that job wasnt so popular.


As to crash rates.... I seem to recall the F-16 has a Class-A rate of 3 per 100,000 hours. Lots are engine related (25%?), but that hardly makes it a deathtrap. In terms of mere numbers, its not exactly suprising, considering the number of Falcons out there.
 
Gibsons. any published figures for missile performance must be taken with a grain of salt. We were not allowed to fire at target drones that were inside the design envelope yet we never had a miss. This is considering that every time we had a kill the envelope was expanded. We had hits at targets beyond twenty miles with a missile advertised for twelve and this was forty years ago. Our missiles came off the launcher with a minimum of nine G's for four seconds, dropped the booster, and then really started to move. Electrical and hydraulic power lasted for a minimum of 240 seconds. The targets we fired at included older versions of SAM's. Some targets were rocket propelled drones with performanc comparable to the Black birds. Of course compounding the question is the fact that the true performance capabilities of the A-11 and SR-71 have never been officially releasded. A fellow I work with was in that program for nine years. He claims that when the SR-71's were transferred from Kadena AFB in Okinawa to the home base at Beale, the trip was flight planned at 4000MPH vs. the advertised 2000MPH. I guess this is a pretty good topic for the "hot stove league".
 
I really do hate that little anecdote. The fact that a flight plan was filed that would suggest that an Sr71 can travel at 4000mph in no way means that they can in fact do so. There are basic science problems with travelling at Mach... 6ish (ie firctional heating), which I am not convinced have really been solved yet, never min in 1970. Ive had this arguement on AT before, so ive no wish to repeat it, but I certainly cannot believe that any Blackbird variant could possibly exceed Mach 4.
 
Supposedly the SR-71 airframe was limited to 3.5-3.6 due to the bow shock impinging on the wings. Cruise speeds were limited by the temp of some engine components (compressor or inlets or something) to 3.2-3.3. Working from memory here, so all numbers subject to change. 😉
 
the cool thing about the sr-71 is that their engines convert from turbojet to ramjet by extending their nose cone. also, most aircraft cruise far below their maximum speed because it places unnecessary wear on parts that is avoidable.
give the russians a little credit😉 they came up with the shkval, didn't they? the shkval is an underwater rocket, which the americans are now improving.link

 
FWIW, at Mach 3 and 80,000 feet the total drag of an SR-71 was 12,000lbs. There were 33,000lbs. of thrust available per engine. In my previous post I didn't make myself clear. When the bird left Kadena a message was sent to Beale. When the bird arrived at Beale it had to be flying near 4000MPH to arrive in the observed time. This is from a man who was in the program for nine years.
 
4000 mph is Mach 6.

Shenanigans!


Edit: quote from Mary Shafer, former engineer (now retired) at NASA, taken from Usenet -


Yes. But it required permission of the Commander on a per-flight
basis. The SR-71's usual limit is Mach 3.2, but flight at Mach 3.3
was allowed, and flown, with prior permission. There's no evidence
that anyone has ever flown faster than Mach 3.3 (although it's
possible that someone may have briefly dashed above 3.3, not cruised,
but it's not documented).

The cruise speed on the SR-71 is limited by CIT, compressor inlet
temperature. The limit is 427 degC, per the Dash-1. Since the SR-71
is designed to fly Mach 3.2 (standard atmosphere), this temperature is
reached at Mach 3.3, offering a fairly standard margin of safety. If
operational conditions require going Mach 3.3 it's possible. Rather
than flying Mach number, we fly CIT, cruising just a bit below the
limit. This usually works out to Mach 3.23 but that's because the
real atmosphere isn't the same as the standard atmosphere. Everything
about the airplane is designed for Mach 3.2, including the inlet spike
operation, etc. I've always assumed that the extra 0.1 Mach was a
bonus, discovered in flight test, because the calculations were on the
conservative side.

If you'll check in Deja News, you'll find that Lednicer worked it out
that the absolute airframe maximum is around Mach 3.5, because you get
the bow shock impinging on the wing above that. Unfortunately, this
can't be tested because the CIT limit is reached first.
Click to expand...
 
Well, fine, but thats a public domain anecdote that he sure as hell didnt need to be working on the Blackbird to know...

Where did you source drag statistics? Ive read that only 20% of the required thrust is produced by the engines without afterburner, and its only when the tetra-ethyl crap kicks in that it can break Mach 3 at altitude.

Also, there is no way you can exceed Mach 4 without using a SCRAMjet. As well as problems like heating, structural integrity of cockpit glass (apparently the limiting factor on A-12s), you simply cannot have supersonic flow into your engines- and above perhaps Mach 4, the shockwave enters the engines and shuts them down. I doubt this has ever actually happened, since it sounds like a Class-A instantly to me, but it would if you pushed the Sr-71 too far.
 
The drag statistics come from a magazine interview of Kelly Johnson. The shockbody at the engine entrance is repositioned automatically to provide the correct shockwave relationship with the engine intake. When supersonic, the engine compression is provided by the shockwave and thus the engine becomes a ramjet. Bendix Talos ramjet missiles did not have the movable shockbody so were required to throttle fuel to keep the missile speed within the operable range. Across a shockwave the speed of the air goes immediately from supersonic to subsonic flow but air pressue becomes very high and there is a sharp temperature difference. In the Kelly Johnson interview, when he was asked about the Blackbirds records being exceeded he said, "There's plenty more under the hood.". He also elaborated that the limitation to speed records was not an aerodynamic limitation but was a matter of being able to turn the aircraft around for the required two-way pass through the traps within the alloted time and without running out of fuel. The turning radius at max speeds was hundreds of miles. Another interesting statement was that there was no way the Russians could duplicate any system in the aircraft let alone the whole aircraft in 20 years.
 
lol @ that last statement. Surely that says more about Kelly Johnson than Russia's aerospace industry. Speeds over closed course in which the Blackbird actually had to turn were in the region of Mach 2.2, so im not suprised there was more to come!

Beyond Mach 4 or so, the spike cannot be extended sufficiently to keep the engine operational. At top speed, all of the compressed air off of the spike essentially bypasses the engine itself, and the afterburner is the vastly larger source of power. Significantly further and you get an unstart of the engine. A turboramjet could not exceed Mach 4 or so, regardless of technical sophistication. If you redesigned the blackbird today, it would not be able to exceed Mach 4 (with the same engine type).
 
There is work being done for hyper-sonic missiles that are meant to kill ships. KEDW is testing these. The X-15 might be able to out run a modern SAM.
 
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