USAF Launch Supersonic Bomb Firing Technology 257
coondoggie writes "Boeing and the US Air Force today said they have tested new technology that for the first time will let military aircraft launch bombs from aircraft moving at supersonic speeds. Researchers from Boeing Phantom Works and the Air Force Research Laboratory used a rocket sled in combination with what researchers called "active flow control" to successfully release a smart bomb known as MK-82 Joint Direct Attack Munition Standard Test Vehicle (JDAM) at a speed of about Mach 2 from a weapons bay with a size approximating that of the U.S. Air Force B-1 bomber, Boeing said. Active flow control is a tandem array of microjets upstream of the weapons bay that, when fired reduces the unsteady pressures inside the bay and modifies the flow outside to ensure the JDAM munition travels out of the bay correctly."
Wow, very much incorrect. (Score:1, Informative)
Brett
Re:This is very handy (Score:5, Informative)
A) SAMs move
B) Enemy fighters aircraft move
If a bomber can fly by at Mach 2 at a high altitude and kick out its load of smart bombs, it becomes much harder to hit it with either a SAM or an air-launched missile. Let's say you make your bombing run at 40,000 feet going Mach 2 and a SAM battery a few miles away takes a shot at you. You kick out the bombs and firewall the throttle for any more speed you can get, and punch out chaff. The SAM is going maybe Mach 5 and you're maybe now at Mach 2.5. At a closure rate of only Mach 2.5, the SAM may run out of fuel before it reaches you, even if it doesn't get fooled by the chaff. If you'd had to slow down to sub-sonic speeds to make your bombing run, the SAM would have a much better chance of catching you.
If there is a CAP up, it's going to have a lot more trouble catching and firing on a bomber going Mach 2 than a bomber going Mach
While these have not been particularly great threats recently (I believe the Viet Nam War was the last time an American heavy bomber was brought down by enemy fire), it wouldn't be wise to assume that the situation will always remain this way, so it's good to have that technology in our back pockets.
Even at lower altitudes, that would take a lot of light anti-aircraft systems off the table, and at least make it harder even for large SAM systems. Imagine being a guy with a shoulder-fired AA missile trying to get a bead on something going at Mach 2. Even if you get a successful lock on it and fire, it's unlikely your missile will be able to catch it even if it's on a low-level bombing run (something I wouldn't expect a B-2 to do, anyway).
Very very incorrect. (Score:5, Informative)
This current little trick is probably a proof of concept for a change to the F-22, which carries free fall bombs such as the JADM in a recessed bomb bay. The B-1b can only do about Mach 1.25 at altitude where the air is thinner. The B-1b was designed as low level penetrator to sneak under Soviet radars. With the end of the cold war, the B-1b started taking over as a high altitude bomber with GPS guided weapons, and not risk itself to ground fire to drop.
The F-22 can cruise at Mach 2 without using afterburners, and I believe it can only carry two Mk-82 JADM weapons. The ability to fly in at Mach 2 while being practically invisible to radar, AND not having to slow down to deploy weapons would be a huge advantage.
Re:Very very incorrect. (Score:3, Informative)
Brett
Re:Very very incorrect. (Score:5, Informative)
The F-22 can dogfight (maneuver at high-G and operate weapons) above Mach 1 which is a major advantage as most of it's contemporaries must be below Mach 1 to do much more than cover ground. Dropping JDAMS at high speed and altitude is another huge advantage which is, as you speculate, what this is probably intended to validate.
Re:Anyone know (Score:4, Informative)
I think most supersonic fighters already have that capability, since the missiles they fire tend to travel much faster than the jets they are chasing down (even the old AIM-9 sidewinder hit mach2.5+), and when launched, are already under power and moving forward in the supersonic flow relative to the aircraft and can thus navigate themselves clear. See Here [army.mil], scroll to SRAM, and that was 1969.
The challenge with dropping bombs at supersonic speed is to get them to clear the bomb bay or wing pylon without the shock of the surrounding air flow blasting it back into the aircraft or otherwise tossing it about or ripping it apart. Not to mention designing a bomb bay and aircraft that can withstand the supersonic shock when the doors are opened.
Tm
Re:This is a REAL sled. (Score:3, Informative)
Re:Good tactics bad strategy (Score:3, Informative)
If I remember correctly during the beginning of the war in Iraq, some cruise missiles were thrown off target when they were jammed by GPS jamming devices. What is to say that technology in the future wont advance to also include jamming the drones you plan to fly over a foes city? Yes I'm sure as technology advances ways of dealing with it will probably be thought of, however as is most often the case with technology (especially military technology) its a back and forth between counter measure and threat.
Being unable to fly your fancy Quake engine virtual reality RC plans over a target does you little good in warfare.
Maybe one day it will be the future, but right now as it stands I wouldn't be holding your breath for it to be the norm for quiet a while.
Those pushing the drones as the next thing tend to remind me of the militarys thinking back when the US entered the Vietnam war. The military believed dog fighting was a thing of the past and all future air engagements would be with missiles from far away. They stopped training pilots in dog fighting skills and instead believed in what they thought the future air engagements would be. It wasn't long before it was apparent this just wasn't the case, the military soon found itself scrambling to train its pilots in air to air combat; the birth of Top Gun.
In case anyone was wondering... (Score:4, Informative)
Maybe not as much fun as dropping real bombs out of a supersonic jet, but pretty darn close
Re:Very very incorrect. (Score:5, Informative)
http://www.airplanes.com/forums/military-aircraft/1411-mach-2-0-supercruise-60-000ft-altitude.html [airplanes.com]
There, you have a claim by a Major Robert Garland to have flown the F-22 at Mach 2 in level flight.
If you google around, you'll find Air Force guys saying that this plane will do Mach 2.5, and, more than a few people have pointed out that the F-22 has a better thrust to weight ratio than the SR-71... thus, all things being equal, this ought to be one fast bird.
Re:Very very incorrect. (Score:5, Informative)
Not rumor, fact [nytimes.com].
A 2000lb guided rock hitting a particular vehicle/tank is just as effective as a 2000lb MK-84.
Re:Very very incorrect. (Score:1, Informative)
Re:Good tactics bad strategy (Score:3, Informative)
Re:*sigh* (Score:5, Informative)
As I see it, any enemy we'd have to use this against would be throwing ICBMs with nukes at us. Why the fuck are we building bigger and better and more expensive bombs when all of our operations are counter-terrorist ops?
You're right, we should be like France before WWII and just invest all our military spending on a single type of defense because it made sense when we started building it. How stupid of us to diversify!
(When France started building the Maginot Line, it was actually impossible for tanks at that time to cross through the forested regions they decided to leave undefended; by the time war actually broke out, tanks could do it with ease and the entire installation was useless.)
Re:Release bombs at supersonic speeds? (Score:2, Informative)
I'm saying that all of the precision guided munitions in the world are only as good as the intelligence that directs them. In other words, it doesn't matter if you can fly a 2000lb laser guided bomb into a window, if the people you really want to get are a mile away.
Anyway, it's been demonstrated that the CIA did not believe that Iraq had or was in the process of acquiring, making or otherwise using any kind of WMD--and that the people with this knowledge in the CIA repeatedly called on the White House to correct misinformation in politicians speeches and shit. The WMD thing was probably, almost exclusively, invented by the white house.
At any rate, it was pretty obvious that Iraq had squat to do with 9/11, and the top echelon were inventing reasons to invade.
Re:Release bombs at supersonic speeds? (Score:3, Informative)
Sorry about the confusion. I definitely agree here.
In other words, it doesn't matter if you can fly a 2000lb laser guided bomb into a window, if the people you really want to get are a mile away.
Then you just need a more powerful bomb, right?
Anyway, it's been demonstrated that the CIA did not believe that Iraq had or was in the process of acquiring, making or otherwise using any kind of WMD--and that the people with this knowledge in the CIA repeatedly called on the White House to correct misinformation in politicians speeches and shit.
So the fact finally hit the US media at last (don't live in the US, so I don't follow those media)?
Fixed geometry inlets (Score:5, Informative)
The problem with a fixed geometry inlet is that it is inefficient. At Mach 2.0 and above, a significant portion of the thrust from a properly designed inlet is coming from the inlet itself. The A-12/F-12/SR-71 cruising at Mach 3.0 gets between 55 and 60% of the total thrust from the inlet - this is accomplished by the positioning the shock wave just inside the inlet (the cons on the front of the engine can be moved in and out specifically for this purpose). One of the early issues with the Blackbirds was figuring out how to handle "unstarts" where the shock wave pops out of the inlet - and gives the crew a wild ride in the process - this was also a problem with the B-58.
The F-16 was also limited to Mach 2.0 because of the fixed geometry wing. OTOH, the F-104 was rated top speed was Mach 2.2, but it could easily achieve Mach 2.4, but at the cost of weakening the aluminum alloy in the airframe.
Re:Very very incorrect. (Score:3, Informative)
Re:Very very incorrect. (Score:4, Informative)
First off, you're forgetting that the F-22 has two of them. The F-16 only has one, capable of about 29,000 lbs of thrust. Each Pratt&Whitney power plant puts out over 35,000 lbs each (w/ afterburner), so that means 70,000+ lbs total thrust.
Second, they're completely different aircraft with completely different goals. So don't compare the two. The F-22 was designed to be an air-superiority fighter to replace the F-15 (they're about the same size). The F-16 is light multi-role fighter with shorter range and payload. Have you ever seen an F-16 next to an F-15? BIG difference... the F-15 is a mammoth, the F-16 is a lawn dart.
Despite this difference, the F-22 has a much larger thrust-weight ratio due to having 2 powerplants (~1.26) compared to the F-16 (~1.1, with updated engine). Fascinating fact: the YF-23 (the ATF competitor to the F-22) had a thrust/weight ratio of over 1.36, which could theoretically push the bird into Mach 3 at altitude (though its top speed is still classified).