F-117A Stealth Fighter Retired 476
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)."
Re:Fuel leaking SR-71's (Score:5, Informative)
Re:Fuel leaking SR-71's (Score:5, Informative)
Re:I still want to know... (Score:2, Informative)
Re:I still want to know... (Score:4, Informative)
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...
Re:Old technology (Score:3, Informative)
Re:I still want to know... (Score:3, Informative)
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.
Re:'Fighter?' (Score:5, Informative)
More information on the role of the F-117 can be found at Frontline [pbs.org], AirToAirCombat.com [airtoaircombat.com], FAS [fas.org] 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.
Re:I still want to know... (Score:4, Informative)
Re:I still want to know... (Score:1, Informative)
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.
Re:Deprecated Warfighting (Score:4, Informative)
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.
Re:Fuel leaking SR-71's (Score:3, Informative)
Re:Fuel leaking SR-71's (Score:5, Informative)
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.
Re:Fuel leaking SR-71's (Score:3, Informative)
Re:Meanwhile... (Score:3, Informative)
Re:Fuel leaking SR-71's (Score:3, Informative)
Re:Fuel leaking SR-71's (Score:2, Informative)
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."
Ben Rich's Book Highly Recommended (Score:5, Informative)
Re:Fuel leaking SR-71's (Score:5, Informative)
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.
Re:Meanwhile... (Score:2, Informative)
Re:I still want to know... (Score:4, Informative)
Re:Deprecated Warfighting (Score:3, Informative)
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.
Re:Fuel leaking SR-71's (Score:3, Informative)
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.
Re:What are they working on now? (Score:5, Informative)
Say hello to the Tu-160 [wikipedia.org]. 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.
F-22 Not a skunk works project (Score:3, Informative)
Re:A good plane (Score:1, Informative)
Silent? I've been to airshows -- The F-117 is LOUD AS HELL.
Re:USAF Deception (Score:5, Informative)
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.
Re:A good plane (Score:3, Informative)
"replace" is incorrect (Score:5, Informative)
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).
Re:Fuel leaking SR-71's (Score:5, Informative)
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
Re:Fuel leaking SR-71's (Score:3, Informative)
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
Re:Fuel leaking SR-71's (Score:3, Informative)
Triethyl borane.
rj
Re:Fuel leaking SR-71's (Score:4, Informative)
Re:Fuel leaking SR-71's (Score:2, Informative)
The fuel leaking issue is fairly well known so you loose points for picking on that issue too. Reference:
http://en.wikipedia.org/ [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.
Stealthiness comparison: F-117 vs. F-22 (Score:3, Informative)
"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."
Re:Fuel leaking SR-71's (Score:3, Informative)
They've got one of these beautiful planes at the Udvar-Hazy flight center [si.edu], 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.
Re:A good plane (Score:3, Informative)
To be honest, they're not all that big either.... apart from those 3 points, the GGP is spot on ;).
Re:Fuel leaking SR-71's (Score:2, Informative)
It's a very cool read.
Re:Fuel leaking SR-71's (Score:3, Informative)
There's a B-2 parked out front that you can walk under. That's quite a sight.
Re:Fuel leaking SR-71's (Score:1, Informative)
Re:Fuel leaking SR-71's (Score:3, Informative)
Re:Imperial assloads (Score:4, Informative)
Re:Fuel leaking SR-71's (Score:2, Informative)
Re:Fuel leaking SR-71's (Score:2, Informative)