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)."

Comments

Fuel leaking SR-71's

[LM741N]

I understand that the SR-71's leaked fuel until they got up high enough so that the vacuum pressed everything together tightly. But speaking of engines, how did they keep the fuel from igniting from the engine while it was leaking?

Re:Fuel leaking SR-71's

[UnknowingFool]

Also the SR-71 would have only just enough fuel to take off and revendevous with a jet tanker as soon as possible.

Re:Fuel leaking SR-71's

[Frosty Piss]

But speaking of engines, how did they keep the fuel from igniting from the engine while it was leaking?

I was stationed at Beale and spent many nights on standby while they fueled the Blackbird. Its fuel is almost impossible to ignite without the catalyst tetraethylborane (TEB), which ignites on contact with air. There where often pools of fuel under the plane when they sat in the hangars for a few days.

The thing that I always thought amazing at the time I worked with them was that the avionics seemed so outdated in an age where most older airframes where being fitted with glass. Lot's of round gages and such.

Re:Fuel leaking SR-71's

[sootman]

And AFAIK, that was by design. They knew it would expand, so they took advantage of that and optimized the plane for flight, rather than sitting on the ground, which makes sense to me. From http://en.wikipedia.org/wiki/SR-71#Fuselage

To allow for thermal expansion at the high operational temperatures the fuselage panels were manufactured to fit only loosely on the ground. Proper alignment was only achieved when the airframe warmed up due to air resistance at high speeds, causing the airframe to expand several inches. Because of this, and the lack of a fuel sealing system that could handle the extreme temperatures, the aircraft would leak JP-7 jet fuel onto the runway before it took off. The aircraft would quickly make a short sprint, meant to warm up the airframe, and was then refueled in the air before departing on its mission... On landing after a mission the canopy temperature was over 300 C, too hot to approach.

I could read about the SR-71 all day long. That thing was a freaking marvel in every sense of the word and there are a million neat details about it, and it's amazing to consider that it was built in the early 60s. One little tidbit you'll often hear (so it must be true ;-) ) -- "if a surface-to-air missile launch were detected, standard evasive action was simply to accelerate and climb." The freaking thing officially flew across the country in 68 minutes.

Re:Fuel leaking SR-71's

[ahabswhale]

I used to be in the Air Force and had the pleasure to watch these things launch. They took off with full afterburners and the entire base would shake from the roar of the engines. Blue flame rings would shoot many feet out the back of the engines. Watching the SR-71 take off was the most amazing thing I've ever seen and I would always stop to watch it. Others who had been in the AF over a dozen years would stop too even though they've seen it launch hundreds of times. Just an incredible and inspiring plane.

You always knew when they were going to launch one because they would start sending out tankers (3 to 4) a good hour or so before they launched the Blackbird.

Re:Fuel leaking SR-71's

[DynaSoar]

Also the SR-71 would have only just enough fuel to take off and revendevous with a jet tanker as soon as possible. A loaded B-52 certainly had to, but the SR-71 didn't necessarily have this profile. The only one I ever saw up close took off from our SAC base without a tanker going along. That's not to say there wasn't a tanker up there (there was another SAC base with tankers only 200 miles away).

More curious to me was the fact that the one we refueled had two LOX tanks, contrary to the manual's statement of only one. It had the normal one under the cockpit, and a second one in the airframe between the wings/engines. I surmise the second was a propulsion system oxidizer. The JP-7 fuel being a kerosene, the combination with LOX would have given it the propulsion profile of rocket motors being used from 1945 on. As a constantly afterburning ramjet at speed, the engines could have easily been adapted to do this.

And frankly I don't recall the one we loaded as having leaked, from hoses-on to taxi-out.

Re:Fuel leaking SR-71's

[MrNiceguy_KS]

Midwesterners can see a retired Blackbird at the Kansas Cosmosphere in Hutchinson. If you're in Wichita, it's about 45 min away, and well worth the drive. They have a space museum that is absolutely amazing, including the Mercury "Liberty Bell" capsule and the largest collection of Soviet space program artifacts outside of the former USSR. I remember when they got the SR-71. They added a whole new entryway to accommodate it.

Re:Fuel leaking SR-71's

[DynaSoar]

You know that plane is still classified and may or may not be in use or ready for use. I'm not sure details regarding the quantity and location of lox tanks are supposed to be well known. I've no doubt it's still classified, as are many much older and now irrelevant things; I know for a fact its true top speed and ceiling still are. I also have no doubt the plane is no longer in service, having been retired 10 years ago. NASA retains two of the original trainers, the only models still living, mostly for high altitude astronomy. All the others are accounted for and in museums. Maintaining and operating an otherwise barely supported craft would be very expensive. One can now get the better results from existing orbital observation craft than the SR-71 could ever produce.

Its reported speed of Mach 3.2 was based on an average speed over a course; that wasn't necessarily the top. A Major Brian Shul reports having sustained Mach 3.5 at 80k ft. And an ex-USAF security police enlisted reports having guarded on in Thailand, and the pilot wore astronaut's wings (USAF astronaut standard is 50 miles, or 264k ft.). The former wouldn't require the mod I described, but the latter would have. The pressure suit used would have allowed flight to this altitude. In fact it does and then some -- it is the suit worn during ascent of the Space Shuttle.

I spoke with a colleague at another SAC base, and he "wouldn't deny" having seen one or more with this mod, but wouldn't say more.

The Blackbird had no effective stealth capability, so if one were still flying it'd be easily seen on today's modern radar and IR devices. Space program/satellite fans would have reported seeing something fitting the profile. Although I can only surmise what the second LOX tank was for, I have no doubt that if I saw it again, and the second fill port weren't removed, I could ID it.

Re:Fuel leaking SR-71's

[tha_mink]

I understand that although several crashed none were ever *shot* down. That would seem to indicate that they could. Or that nobody ever shot at one. Though that's not true because it's well documented that it has outrun them missiles in the past. Real high and real fast is hard to shoot down unless you've got a real big head start.

Microprose

[tangent3]

My fondest memories of the F117 is playing the Microprose simulator. The original version was named F19 Stealth Fighter until the F117 was declassified in which the version 2.0 of the game, updated with VGA graphics and Persian Gulf campaigns was renamed F117A Stealth Fighter.

It was quite an interesting change, whereas in most other combat flight simulators like Falcon 3.0 and F15 Strike Eagle I would be actively seeking a fight with any enemy on my radar and pumping them full of sidewinders or 20MM, in F117A the mission is to avoid the enemy patrols and ground radars

Deprecated Warfighting

[TellarHK]

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.

Two bombs, no Air-to-Air capability other than playing "How not to be seen." really well, and subsonic speeds just seemed to make the F-117 come across as oddball in my eyes. Either the F-22 has better stealth than we realize, or there's something newer, more stealthier and more secretive coming around.

Re:Deprecated Warfighting

[hcdejong]

Count on the F-22 having better radar stealth than the F-117. The F-117 fell victim to Moore's law: During its design, all the engineers were capable of simulating (for stealth characteristics) were flat panels, hence the faceted skin, which dictated the rest of the design.

The size was another compromise (smaller = easier to hide), and the engines didn't have afterburners to minimise the IR signature, which meant no supersonic flight. Radar technology wasn't advanced enough to build a low-observable (or Low Probability of Intercept, LPI) air search radar, and a 1970's radar would compromise the aircraft's stealthiness even when turned off.

Oddball maybe, but the F-117 was the best possible design with 1970s technology. To get it to work at all, everything else had to be sacrificed for the one mission that couldn't be done by any other platform: surprise attacks.

Re:Deprecated Warfighting

[maxume]

The stealth technology at the point the plane was designed required that the plane have flat surfaces. The plane was built, on purpose, in the face of a major design limitation. As much as anything, it was a proof of concept that got more funding than it should have(i.e., the military probably didn't need to actually buy a production run).

The F-22 might not have better stealth than we realize, but it is pretty clear that it is a whole new class of aircraft(beating expert F-15 pilots 3 to 1 is no joke) and it is stealthier than anything else that provides similar capabilities.

A good plane

[Protonk]

The F-117 has a great history and it will be interesting to see it go. I'm not normally the military tech-fetishist type, but this was a supremely odd creature that got to fly. Embodied in this plane are so many examples of ingenuity and hubris, it makes a good vessel for late 20th century american history.

We developed this plane in secret, with borrowed theories from the russians. The plane itself came out of a corporate Manhattan project, built by a combination of old salts who could wave their hands and make grumpy generalizations about engine configuration that hours of calculations would bear out and younger engineers employing technology that wasn't readily available outside the united states.

It was kept secret until we felt the need to unveil it as the epitome of american superiority in Panama and the gulf war. We spent a decade lauding the precision strike capability, ignoring reports that smart bombs were only so smart. Only in the past 5 years have we grudgingly come to accept that there were limitations to the strategy of aerial bombardment, limitations that hampered our ability to fight and killed civilians on the ground. But that doesn't make this plane or its pilots evil or murderous. We just became caught up in the technology, the gritty night vision cameras resulting in static filled screens where buildings used to be.

In a lot of ways, that is similar to our love affair with this plane. Ugly, but elegant. Unflyable without computer aided control but possessing strangely beautiful lines. Born of american ingenuity and sullied by hubris. It is a wonderful aircraft, and a great story. Thanks to the men (and women) who built it and flew it throughout the years.

Re:What are they working on now?

[PortHaven]

Nah....

The F-22 is the real "stealth fighter". The F-117A was the stealth attack craft/tactical bomber.

Fighters usually aren't all that super secret. But reconnaissance, and strategic assault vehicles. Now those are secret.

The F-117A's mission is likely to be super-seded by unmanned stealth drones.

The SR-71 was retired a while back. The F-117A was NOT a replacement for the SR-71. Rather, both operated concurrently for some time.

The mostly likely replacement for the Blackbird is the Aurora project. Sometimes caught by seismologists and observers. Rumored to use a a pulsating scramjet and being the mach 5-8 range.

Then there is the B2 (flying wing) bomber and the B1-B The B1-B being famous for numerous crashes. Though very few in later years. What was the change? The government had been only doing 85% of the maintenance recommended for the bombers by it's manufacturers. They began doing the full maintenance recommended maintenance, fluid changes, etc. Things ceased failing...go figure.

USAF Deception

[tjstork]

Actually, just the F117 Night Hawk is a bomber as far as I know

The F- designation was actually deliberate. The USAF didn't want enemies to know that this was a bomber, not a fighter, so they named it differently.

B-52 reverse-Stealth System

[PortHaven]

There was a proposition to modify the B-52's with reverse-stealth technology.

A similar idea had been proposed for the B-52's a few years ago. Since you can't really make such a craft stealth, how do you keep them viable.

Well B-52s are mainly used in one of two capacities. Single bomber support role, carpet bombing (albeit with more intelligent bombs these days) in prep for a land transaction. Or the more purposeful original intention of a strategic bomber. In which case a whole flight of bombers would be sent out to level much foe.

But with radar and missiles, how can such aircraft get to their targets.

I used to work on a 90ft schooner (sailboat for the landlubbers). Anyways, we had a radar reflector that would make us show up much larger on radar.

The idea was to go the opposite route. Instead of stealth, have all the B-52's light up those radars as bright as they can. So instead of seeing the large B-52 on the radar you'd see something akin to the size of the ships in Independence Day. Huge giant radar blob. In fact dozens of giant radar blobs.

So yes, you'd know something was coming. The radar makes that clear. But trying to pin point it's exact position and mobilize fighters becomes more challenging because well, it's showing up in almost a mile of air space or more. I don't think the Air Force ever went thru with the expense. But one never knows...it might have been done and listed as $200 toilet seats. ;-)

Re:What are they working on now?

[peragrin]

Actually the SR-71 served damn well until we put enough DIGITAL satellites into Orbit. The reason why the SR-71 was so useful was because the film canister could be brought back down quickly to develop the images. That didn't work so well for Satellites.

The SR-71 is one of my all time favorite planes. One has to remember it was built with 1960's tech, as such digital computers and camera's weren't available yet.

The F-22 is impressive to see

[The Second Horseman]

Saw one at the air show in Rhode Island last year. The first thing you notice is how damn loud the thing is. Compared to an F-15, F-16 or F/A-18's I've seen at shows, it was just painful, not uncomfortable. Even good earplugs didn't really help - you really need substantial ear protection, and even then you're likely to feel it in your skull. Aside from that, the big thing I noticed was how rapidly it could change speed and its maneuverability. Compared to the older aircraft it's like watching a superball bounce around. If you had no idea that the plane existed and you saw it at night in the sky at a distance, you'd never believe it was an aircraft. The thrust vectoring looked really effective. You don't have to know a lot about aircraft to see the difference, either - you can watch an F-22 after seeing another demonstration and the difference is obvious.

SR71 took JP7

[Firethorn]

Jet fuel is a mixture of gasoline and kerosine.

Not really. Depending upon the grade, it's its own distillate from the stack.

There's different grades of jet fuel. For the SR71, it was a very special blend, closer to diesel then kerosine, but still designed to be liquid in both far colder and far hotter temperatures.

The match trick works fine with it, for example.