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F-117A Stealth Fighter Retired
zonker writes "Nearly 30 years ago Lockheed Martin's elite Skunk Works team developed what would become the F-117A Nighthawk Stealth Fighter. A few of their earlier projects include the SR-71 Blackbird and U2 Dragon Lady spy planes. Today is the last for the Stealth Fighter, which is being replaced by the F-22 Raptor (another Skunk Works project)."
No - it wasn't the vacuum it was the heat from the drag caused by the supersonic speed that heated the plane enough to stop the leaks.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
They leaked fuel until the heat caused by friction (like on the space shuttle) made the panels fit together by thermal expansion. The fuel was also very difficult to ignite.
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
Because back in the day when it was being designed they called it a fighter to confuse potential spies.
First, fighters generally attract the better pilots than bombers, and since the F117 was a first strike or tactical strike craft, good pilots were of utmost importance...
Second, naming it as a fighter helped with the secrecy surrounding its true capabilities and use, especially in Cold War times...
Eat a Chicken, You know you want to.
Link is a GNAA troll. Fuck you, anonymous coward. There were also way more fighter planes in WWII than F117As. And the tech in them is probably still classified? *shrug*
which is totally what she said
I loved that game, but what always struck me as mildly depressing was playing the classic "Jetfighter II" which had the YF-23 "Black Widow" in it, the plane that eventually lost out to the F-22 in that round of fighting proposals. The YF-23 was such a gorgeous concept.
Of course, the best thing about Jetfighter II was mid 90's game physics. I fondly recall the time I landed a YF-23 on a carrier with a three-point landing due to intentional stalling at 10 feet off the deck. Low and slow, vector thrust upward, kill the throttle entirely and glide over the deck until you pop flaps and yank the nose up until you nail a stall then level off with gear down and just drop.
My own pointless vanity vintage computing page
More information on the role of the F-117 can be found at Frontline, AirToAirCombat.com, FAS as well as other sources on the intertubes. Last link has pictures of the aircraft as well as pictures and a non-Flash video of the aftermath of the only F-117 to ever be shot down. In this case, over Serbia.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
Um - no it doesn't "make the radar bounce back". Radar works by bouncing back a signal to detect. Meaning if it did - it wouldn't be invisible at all - it'd be working with radar just dandy. It deflects the radar's signal to produce a much smaller return signal. Meaning it was never "invisible" but had a small enough cross-section to be regarded as a non-threat.
Actually the 117-B had the AMRAAM and Sidewinder missile capability, but was largely unused.
One reason was obvious - you had to have the bomb bay doors open to fire them.
I believe they also had to fly level to the ground to deploy the missile properly.
Then in order for the missile to track, painting the target with radar also broke stealth.
So a bad combo for an interceptor, esp given the price tag versus other fighters.
Given the level of C&C where the 117 was flying, there was probably never a significant
threat from enemy aircraft in any sortie, anywhere. That threat died with the CCCP.
Both. The F-22 is the first true stealth fighter, the B-2 is the first true stealth bomber. The F-117 was really a stealth hack. That said, given the long developement times on aircraft, there is always something newer in the works. Also, fighters (among other things) are made to be upgradeable over their lifespan. There have been 3 different generations of the F-18 for the military alone and the older ones are usually upgraded along the way instead of being replaced. That is in addition to 'minor' upgrades such as electronics. If you want to know what is cuttin edge today, you need a high level security clearance and to be in the need to know.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
There was an episode of Mythbusters which, while not directly related, did show that diesel and jet fuel would not ignite even under a plumbers blowtorch.
As always, it's the air/fuel mixture that's the important part. This does not hold for gasoline, which gives off vapors quite nicely, thank you.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
The B-52s are coming back, though, and I do mean the band. Funplex is the new album. o hai - im in ur lurv shakk, roman w/ all ur rock lobstahs
Jet fuel VAPOR, on the other hand...
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Actually it's because the SR-71 doesn't use normal Jet Fuel. Typical fuel for large jet engines is US Jet A1 which is a kerosene-based fuel and it is very flammable. The Blackbird's engines used something called JP7 which has a very high flash point. You can actually drop a lit match into a bucket of JP7 and the match will simply go out.
In order to get ignition to start the engines initially, an additive chemical needed to be used to get the fuel's flash point temporarily lowered.
And don't get me started on the "Pierre Salinger Syndrome."
If you enjoy this kind of thing, I can't recommend Ben Rich's book Skunk Works: A Personal Memoir of My Years of Lockheed highly enough.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
So, post your evidence.
We've seen that if you have three feds in a conspiracy, one will blab to the Washington Post, so... name your source.
. . .
I suspect I'll be waiting a long time.
The center tank on TWA Flight 800 was almost empty, overheated and full of fumes, and likely a spark from a poorly wired fuel sensor detonated it.
Oh, if you were kidding, it wasn't funny, emoticon or no.
You can't talk about Wikipedia's flaws on Wikipedia
Air Combat Maneuvering - dogfighting or missile evasion.
Caution: Do not stare into laser with remaining eye.
My understanding, based on talking to people who have designed systems to detect stealth aircraft, is that the OP is half right. The reason the F117 has all those big blocky facets is specifically to bounce the radar back in very direct lines, like a planar mirror, rather than in all directions, like a sphere. The idea being: you absorb as much as possible in your weird ferroabsorptive paint, but what you have to reflect, you reflect in thin lines rather than in broad arcs, and if possible you reflect them upwards, away from the radar receivers.
Nostalgia's not what it used to be.
"In a day and age where aircraft from the 1950's are still flying and in active service, to see something like the F-117 come and go so quickly has to be a sign of major design limitations from the first day of use."
You are forgetting that fighter/attack aircraft lifecycles are much shorter than airlift/tanker lifecycles. There isn't a technology "race" with airlifters and tankers, or heavy strategic bombers like the B-52. Fighter/attack systems are obsoleted much more quickly.
Another factor in retiring the 117 is that the Air Force is _desperate_ for money to replace aging aircraft it should have replaced years ago. That means dumping lots of support people such as personnellists, retiring every system they can, and focusing on priority number one which is total air dominance. Offing the 117 frees up the many people supporting it to shift to the Raptor.
"This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
Presumably the temperatures were only present in the engines, so the exhaust itself wasn't hot enough to catch any leakage on fire once the engines were going.
Say hello to the Tu-160. And, yes, it look an awful lot like the B-1.
Also note that the B-1B has a maximum speed of Mach 1.25 at altitude. The rapid advances in air-to-air missiles in the 1960s and 1970s changed USAF planing for bomber missions. Instead of flying high and fast (which just makes you a perfect target for SAMs unless you're an SR-71) the idea is fast and low, which is why the B-1s mission profile was changed to flying very fast at very low altitudes. Of course now the thing usually just hangs out on station waiting to be told where to drop its bombs.
I am a believer of momentum and curves.
The F-22 was not a Skunk Works project. The F-22 program was acquired when Lockheed bought the General Dynamics Ft. Worth division which is now The Lockheed Tactical Aircraft division.
> It was very creepy seeing this big, silent, killing machine, hovering over me
Silent? I've been to airshows -- The F-117 is LOUD AS HELL.
Numbers restarted from 1 starting in 1962, when the Navy and Marines switched to the Air Force's style of aircraft designations.
Prior to that, a fighter might be designated F8U-3 -- that breaks down to Fighter, Design 8 from Vought (Vought's code was U), 3rd revision. Under the new designation system, that'd be the Vought F-8C Crusader. If it was the first design of a particular type from a company, it'd lack the middle number, e.g. the Douglas AD-2 Skyraider, which was later known as the A-1B Skyraider.
Hail Eris, full of mischief...
E pluribus sanguinem
As far as I know they don't hover too well, either. GP must have taken some bad acid that day.
Seven puppies were harmed during the making of this post.
The F-117 and the F-22 have two completely different missions, therefore the F-22 cannot "replace" the F-117. The F-117 is a first-strike night attack bomber, deploying, mostly, precision-guided munitions. It took on roles that would have required much larger formations had they been done with the F-111 (replacement for the F-105) which had much higher visibility, so needed escorts and AA suppression. The F-22 is supposed to replace the aging, but still very potent, F-15 as an air superiority fighter, while the F-15 is shuffled off to the strike fighter role as the F-15E.
F-22s are much more expensive than F-15s. In theory, they are able to provide more kills-per-sortie than the F-15, so we would need fewer of them. The problem with that is that, despite supersonic cruise, there is only so much airspace that an F-22 can control, so, if the missions are geographically dispersed, a larger number of F-15s can provide more coverage.
There is no longer an opposing air force in Iraq, and the Iranians were stupid enough to buy planes from us, so they don't really have one, either. Other than the US, there is almost no long-range bomber capability, so the only remaining function for the F-22 is as an escort for B-2s on first-strike missions into nations with active fighter forces, such as Russia, China, and Western Europe (if they don't stop picking on Microsoft).
You are both right and wrong. I'll try to clarify. The heat transfer between a fluid and a solid wall happens a the viscous zone so called boundary layer, where friction happens. On the other hand, the temperature which modulates this heat transfer is the external flow total temperature which is where viscous effects are negligible.
:P
The total temperature is given by the compressible isentropic flow behaviour:
Tt/Tamb = 1+ (k-1)/k*M^2, where
Tt is the total temperature in K or Rankine,
Tamb is the ambient temperature in same units above,
k is the heat coefficient ratio, for the air is 1.4 and
M is the mach number.
Thus, for a 3.5 Mach number, the maximum for SR-71, the total temperature is:
Tt = Tamb*(1+0.29*3.5^2)=Tamb*4.5,
and for a Tamb of -50 degrees celsius (-58 deg Fahrenheit), becomes,
Tt = 223*4.5=1003K = 730 deg C = 1346 deg F
At that speed, the ambient is sooooo hot! even when the atmosferic temperature may be soo freezing!!!!.
At the leading edge of the SR-71 wings and the fuselage nose, you reach such temperature without any kind of viscous effects; just because you stagnate the flow isentropically there: you are more right than wrong at the end
Now get yourself moving very fast, and any molecules that hit the front side of your body will have an ordered component of velocity added to the statistical disordered component you've been experiencing, and they'll hit you harder. Likewise, the ones hitting you from behind will hit less hard. You'll feel hotter in front and cooler on your butt. You haven't noticed it, because you've never been in enough wind to make a significant difference, but high-speed airplanes are a different story.
Pressure is a related but different issue: it depends on the mass of the molecules and the frequency of impacts, in addition to the velocity. Friction is not an issue; the molecules heat the surface by bouncing off it, not by rubbing along it.
If you get the chance, watch a Shuttle landing on one of the NASA feeds that shows the view from an infrared camera that gives a black-and-white image with brightness representing the temperatures. You'll see the nose and leading edges glowing white from the reentry heating: that's particle impacts at work. Then as it touches down, you'll see the tires light up like spotlights; that's friction at work.
rj
Triethyl borane.
rj
There's a reason the empty center tank is also called the "Pacific" tank.
I'm sorry but your sentence structure should really preclude you from complaining about other's grammar. :)
The fuel leaking issue is fairly well known so you loose points for picking on that issue too. Reference:
http://en.wikipedia.org/
The leaks were more a design compromise than a design flaw from what I have heard. The leaking expansion joints in the fuel tank were required to allow the relatively huge expansion that occurred when the plane got up into its common operating temperature ranges. At mach 3 the heat from air friction soaking into the plane expanded the metal around the joints (along with everything else) and stopped the leaks. The joints allowed the expansion to take place without overly stressing the fuel tank.
I can only guess that the planes that you saw were empty and thus not leaking.
And as you tread the halls of sanity, You feel so glad to be, Unable to go beyond. I have a message, From another time..
"Aircraft designers generally describe an airplane's radar cross section in terms of "decibel square meters," or dBsm. This is an analogy that compares the plane's radar reflectivity to the radar reflectivity of an aluminum sphere of a certain size. The B-2 reportedly has a radar signature of an aluminum marble. The F-22 Raptor interceptor is roughly the same, and the F-117 is only slightly less stealthy. The newer Joint Strike Fighter has the signature of an aluminum golf ball. The older B-1 bomber, designed during the 1970s and 1980s, is about the size of a three-foot (one-meter)-diameter sphere, whereas the 1950s-era B-52 Stratofortress, a monstrously non-stealthy airplane, has an enormous radar cross section of a 170-foot (52-meter)-diameter sphere. The size of an aircraft has little relationship to its radar cross section, but its shape certainly does."
They've got one of these beautiful planes at the Udvar-Hazy flight center, near Dulles airport (Outside Washington, DC).
It's worth a trip well-out-of-your-way to see the thing - you can get right up close to it, and it is astonishingly attractive; moreso for being so secret and rare.
There's a whole bunch more good stuff at Udvar-Hazy - a great aviation museum.
To be honest, they're not all that big either.... apart from those 3 points, the GGP is spot on ;).
Here's the Pilot's Operating Handbook for the SR-71: http://www.sr-71.org/blackbird/manual/
It's a very cool read.
My favorite quote doesn't fit into 120 characters. Now no one will like me.
There's one at the Hill AFB flight museum in Layton, Utah as well. You can walk right up and touch it.
There's a B-2 parked out front that you can walk under. That's quite a sight.
In "Sled Driver" it's stated that the SR-71 was shot at a bunch of times. Result: there was one near miss during Vietnam (but the Blackbird took no damage - it wasn't *that* near), and despite dozens of SAMs launched during the bombing of Libya the SR-71 was never in real danger. Brian Shul (former pilot/author of "Sled Driver") won't say what the real top speed was, but there are hints that he had it running fine at Mach 3.4+ on several occasions, including over Libya. In ramjet mode (ie, Mach 3+ cruise) the SR-71 got more fuel efficient the faster you went, so there was no real penalty to pushing the speed if you were careful. An absolutely brilliant piece of engineering, and IMO one of the top "hacks" of all time considering it was hand-built with late 50s technology at a time when no tools existed to work with titanium.
The important thing is that you were *wrong* about the leaky airplane. Plus, you were smarmy. *Plus*, you went on a rant about apostrophes with poor sentence structure. So like, three strikes. Go away now.
You'll have that sometimes...
A B-52 carries up to 70000lbs in bombs, so an imperial assload would be 46667lbs. A new beetle weights 2743lbs, so an imperial assload is almost exactly 17 (2005) VW beetles, not including any imperial asses (passengers).
Wright Patterson AFB in Dayton, Ohio has an SR-71A, B-2A, F-15A, F-111F, and U-2; and that's just in the Cold War gallery.
And for those of us in the UK, the only Blackbird on display outside the US is at Duxford in Cambridgeshire.