7 ms·

How To Take Down an F-117

46 points by jscore 16y ago

jcapote 16y ago
This article is really hard to read. It basically boils down to: "He developed some ideas on how to beat stealth, based on the fact that the technology didn't make the F-117 invisible to radar, just very to get, and keep, a good idea of exactly where the aircraft was. Zoltan figured out how to tweak his radars to get a better lock on stealth type targets. This has not been discussed open" I wish they went into more detail as to how they did that.
- lmkg 16y ago
  I would be interested to learn that as well, but that's not what "it basically boils down to." There was a considerable amount of effort in avoiding countermeasures against his radar and detection systems. He beat the stealth planes just as much by out-stealthing them on the ground as by de-stealthing them in the air. I find that just as interesting, and possibly more valuable.
- andyv 16y ago
  Perhaps something along the lines of "Use the radar to look for the bird flying at 600mph"...
  - runjake 16y ago
    I'm not sure why andyv was downvoted, other than the fact he quoted me in a prior thread without citation? ;) This is the conclusion the US military drew and was corroborated by Ben Rich (the "father" of the F-117) in his book.
- Dove 16y ago
  I wish they went into more detail as to how they did that. Well, you should expect practical information on beating stealth to be about as easy to come by as practical information on building nuclear weapons. That said, the wikipedia entry for Nighthawk has a little more information: http://en.wikipedia.org/wiki/F-117_Nighthawk#Combat_losses http://en.wikipedia.org/wiki/F-117_Nighthawk#Combat_losses According to NATO Commander Wesley Clark and other NATO generals, Yugoslav air defenses detected F-117s by operating their radars on unusually long wavelengths, making the aircraft visible to radar for brief periods. It is also possible that the aircraft was visible due to a disruption of its radar signature caused by open bomb- bay doors. This was the justification given by Colonel Dani in a 2007 interview. And http://en.wikipedia.org/wiki/Stealth_technology#Radar_stealth_countermeasures_and_limits http://en.wikipedia.org/wiki/Stealth_technology#Radar_stealt... has information about stealth technology counters in general, the sort of thing you might find in a radar engineering handbook.
jleyank 16y ago
I have to check, but I thought they used AAA to take the F-117 down. If so, such things are statistical - put enough metal in a volume of space suspected of having a plane, rinse, repeat. If he had the intel to guestimate the location or path of a plane, it's just a matter of time before the thing gets hit. update: some searching revealed that low-frequency/old radars picked it up and some form of SAM got it. But there were bullet holes in the wing, too. If there was a hostile fighter up, that would work if it could be guided close enough. I've read previously that old/low-freq radars would be more effective as they weren't what was modeled when the thing was built. The stuff's not magic, although the press and popular literature makes it out as such. Far better to fly things w/o a pilot, as holding missile fragments for hostage doesn't generate much interest.
- lucasjung 16y ago
  It was the missile. However, he did know where to point it well ahead of time before firing. As the article mentions, he used visual cueing and short-range shots to minimize the time his radars were transmitting. One thing this article didn't mention: when it came to predictability, NATO aircraft were the polar opposite of Zoltan--they often flew the same routes, at the same times, using the same radio callsigns, day in and day out. This made it very easy for him to predict where an airplane would be. In the case of the F-117, I have heard that the pilot made back-to-back passes over the same target and was shot down on the second pass. I also heard an apocryphal story about Zoltan: After the war he was "debriefed" (not really an interrogation, since the war was over and he hadn't committed any war crimes, but not exactly a friendly chat, either) in order to learn his tactics. After a while, his interviewers realized that he believed that the NATO forces were so arrogant that they had deliberately tipped their hand to him: he couldn't understand any other plausible reason why they had been so bad at keeping secrets, especially in regards to the movements of their aircraft. When they tried to explain that they had thought they were practicing good security, he refused to believe them and accused them of lying--nobody could be THAT bad at keeping secrets!
  - nl 16y ago
    I hadn't heard that story, but I think I'd believe it. There are a few references around to how some of his intelligence network involved people sitting outside (military) airports in Italy and phoning in when F-117's were taking off.
jscore 16y ago
More info here: http://en.wikipedia.org/wiki/Zolt%C3%A1n_Dani http://en.wikipedia.org/wiki/Zolt%C3%A1n_Dani Looks like Zoltan is a baker now in his home village in Serbia after retiring from the military. If he was a US general, he'd have a book, do media tours all over the country, and perhaps even run for office.
- ryanwaggoner 16y ago
  He was a colonel, not a general. And even then, the US has hundreds of generals and admirals, most of which just retire and go on to a quiet 2nd career or retirement. The ones you see on CNN are the exception.
akamaka 16y ago
Previous discussion: http://news.ycombinator.com/item?id=799494 http://news.ycombinator.com/item?id=799494
dkokelley 16y ago
The writing is difficult to read, but the moral of the story is good: Effectiveness = Technology * People. Zoltan had good people to compensate for antiquated technology, whereas NATO had modern tech, but the human factor negated much of the tech advantage. Also, the title is misleading. The article is more about how to hide than how to neutralize the F-117. Being nimble, using landlines, and understanding the enemy helped Zoltan outfox those who would try to stop him.
runjake 16y ago
We recently discussed this in another thread, but one of the low observability (stealth) characteristics of the F-117 was a reduced radar cross section (visibility) using flat sections of fuselage in a faceted manner. This was calculated by hand by Skunk Works engineers. They didn't have the benefit of computerized physical modeling back then. They were able to reduce the radar visibility to a size about that of a bird (it's actually a little larger, iirc). My understanding with Zoltan is that he just looked birds flying at 500-600mph. He claims that he invented all this complex, custom gear accompanied by advanced-sounding jargon, but the US military dismissed it as hyperbole (which Zoltan is known for). The B-2 had the benefit of computer-aided physical modeling which explains it's lack of facets. The B-1 and B-52 also have low observability characteristics to reduce their radar and infrared characteristics (although they aren't known as "stealth" aircraft). I think that stealth aircraft as we know them are largely obsolete. Hence, the increased focus on UAVs and satellites. I have some ideas about where to go next, but the costs would make the B-2 look like a Girl Scout cookie sale. Disclaimer: I worked on many of the above-mentioned aircraft.
- stratomorph 16y ago
  >The B-1 and B-52 also have low observability characteristics I'd challenge the B-52 bit. The airframe had pretty well reached its final form by 1950. Radar was still in its infancy, let alone radar countermeasures. The plane is all radar-inviting angles (like the giant vertical stab), and there wasn't even an attempt to shield the engine exhausts from IR sensors, as IR homing weapons didn't exist at the time. I'd go so far as to say the B-52 is about as high-observable as an airplane gets. Edit: Maybe you mean active countermeasures?
  - runjake 16y ago
    You are correct about the airframe, but the airframe wasn't what I was referring to. http://en.wikipedia.org/wiki/Radar-absorbent_material http://en.wikipedia.org/wiki/Radar-absorbent_material Active countermeasures aren't very stealthy except when you're attacking a specific detection system.
    - 16y ago
poi98u7y6tryuio 16y ago
So he used training and tactics - isn't that rather unsporting? I thought the idea was we only flew expensive aircraft against people living in caves (or at weddings) or at least stuck to bombing those with no anti-aircraft ability. Poor people shooting back at $Bn aircraft just isn't fair.
- PostOnce 16y ago
  Who said it was unsporting?
ajays 16y ago
Personally, I think this bit was the key: The Serbs had spies outside the Italian airbase most of the bombers operated from. When the bombers took off, the information on what aircraft they, and how many, quickly made it to Zoltan and the other battery commanders. My guess is, if you know how many airplanes are on their way and at what time, you can prepare. Knowing the ground speed, you can estimate when they're going to be above you and quickly light up your radar, take a pot shot, and then turn it off and scoot.
yread 16y ago
There was also this rumour going around that f117 can in fact be detected by passive systems Tamara and Vera. see http://72.52.208.92/~gbpprorg/mil/radar/tamara02.htm http://72.52.208.92/~gbpprorg/mil/radar/tamara02.htm
- mjb 16y ago
  Optimisation for stealth against bistatic and multistatic radar systems is a different problem from the monostatic case. The important thing is the split between the position of the transmitter and receiver. In the monostatic (transmitter and receiver in the same place) case, you need to optimise to reduce radar energy reflected back in the direction of the transmitter. When the receiver and transmitter are split, this problem gets harder, because you need to optimise to reduce radar energy transmitted back in the direction that recievers are likely to be (or don't reflect any, but that's a different problem). This becomes even harder in multi-receiver systems, and even harder in multi-receiver-multi-transmitter systems. As computation power and communication bandwidth becomes cheaper, lower power, smaller and easier to hide, many of the assumptions used during the development of the current generation (and past generations) of stealth aircraft are becoming invalid. Passive location systems, either secondary radars or systems using 'transmitters of opportunity' also reduce the effectiveness of anti-radiation weapons significantly. The radar vs. stealth arms race continues.

46 points by jscore 16y ago

This article is really hard to read. It basically boils down to: "He developed some ideas on how to beat stealth, based on the fact that the technology didn't make the F-117 invisible to radar, just very to get, and keep, a good idea of exactly where the aircraft was. Zoltan figured out how to tweak his radars to get a better lock on stealth type targets. This has not been discussed open" I wish they went into more detail as to how they did that.

lmkg 16y ago
I would be interested to learn that as well, but that's not what "it basically boils down to." There was a considerable amount of effort in avoiding countermeasures against his radar and detection systems. He beat the stealth planes just as much by out-stealthing them on the ground as by de-stealthing them in the air. I find that just as interesting, and possibly more valuable.
andyv 16y ago
Perhaps something along the lines of "Use the radar to look for the bird flying at 600mph"...
- runjake 16y ago
  I'm not sure why andyv was downvoted, other than the fact he quoted me in a prior thread without citation? ;) This is the conclusion the US military drew and was corroborated by Ben Rich (the "father" of the F-117) in his book.
Dove 16y ago
I wish they went into more detail as to how they did that. Well, you should expect practical information on beating stealth to be about as easy to come by as practical information on building nuclear weapons. That said, the wikipedia entry for Nighthawk has a little more information: http://en.wikipedia.org/wiki/F-117_Nighthawk#Combat_losses http://en.wikipedia.org/wiki/F-117_Nighthawk#Combat_losses According to NATO Commander Wesley Clark and other NATO generals, Yugoslav air defenses detected F-117s by operating their radars on unusually long wavelengths, making the aircraft visible to radar for brief periods. It is also possible that the aircraft was visible due to a disruption of its radar signature caused by open bomb- bay doors. This was the justification given by Colonel Dani in a 2007 interview. And http://en.wikipedia.org/wiki/Stealth_technology#Radar_stealth_countermeasures_and_limits http://en.wikipedia.org/wiki/Stealth_technology#Radar_stealt... has information about stealth technology counters in general, the sort of thing you might find in a radar engineering handbook.

jleyank 16y ago

I have to check, but I thought they used AAA to take the F-117 down. If so, such things are statistical - put enough metal in a volume of space suspected of having a plane, rinse, repeat. If he had the intel to guestimate the location or path of a plane, it's just a matter of time before the thing gets hit. update: some searching revealed that low-frequency/old radars picked it up and some form of SAM got it. But there were bullet holes in the wing, too. If there was a hostile fighter up, that would work if it could be guided close enough. I've read previously that old/low-freq radars would be more effective as they weren't what was modeled when the thing was built. The stuff's not magic, although the press and popular literature makes it out as such. Far better to fly things w/o a pilot, as holding missile fragments for hostage doesn't generate much interest.

lucasjung 16y ago
It was the missile. However, he did know where to point it well ahead of time before firing. As the article mentions, he used visual cueing and short-range shots to minimize the time his radars were transmitting. One thing this article didn't mention: when it came to predictability, NATO aircraft were the polar opposite of Zoltan--they often flew the same routes, at the same times, using the same radio callsigns, day in and day out. This made it very easy for him to predict where an airplane would be. In the case of the F-117, I have heard that the pilot made back-to-back passes over the same target and was shot down on the second pass. I also heard an apocryphal story about Zoltan: After the war he was "debriefed" (not really an interrogation, since the war was over and he hadn't committed any war crimes, but not exactly a friendly chat, either) in order to learn his tactics. After a while, his interviewers realized that he believed that the NATO forces were so arrogant that they had deliberately tipped their hand to him: he couldn't understand any other plausible reason why they had been so bad at keeping secrets, especially in regards to the movements of their aircraft. When they tried to explain that they had thought they were practicing good security, he refused to believe them and accused them of lying--nobody could be THAT bad at keeping secrets!
- nl 16y ago
  I hadn't heard that story, but I think I'd believe it. There are a few references around to how some of his intelligence network involved people sitting outside (military) airports in Italy and phoning in when F-117's were taking off.

jscore 16y ago

More info here: http://en.wikipedia.org/wiki/Zolt%C3%A1n_Dani http://en.wikipedia.org/wiki/Zolt%C3%A1n_Dani Looks like Zoltan is a baker now in his home village in Serbia after retiring from the military. If he was a US general, he'd have a book, do media tours all over the country, and perhaps even run for office.

ryanwaggoner 16y ago
He was a colonel, not a general. And even then, the US has hundreds of generals and admirals, most of which just retire and go on to a quiet 2nd career or retirement. The ones you see on CNN are the exception.

akamaka 16y ago

Previous discussion: http://news.ycombinator.com/item?id=799494 http://news.ycombinator.com/item?id=799494

dkokelley 16y ago

The writing is difficult to read, but the moral of the story is good: Effectiveness = Technology * People. Zoltan had good people to compensate for antiquated technology, whereas NATO had modern tech, but the human factor negated much of the tech advantage. Also, the title is misleading. The article is more about how to hide than how to neutralize the F-117. Being nimble, using landlines, and understanding the enemy helped Zoltan outfox those who would try to stop him.

runjake 16y ago

We recently discussed this in another thread, but one of the low observability (stealth) characteristics of the F-117 was a reduced radar cross section (visibility) using flat sections of fuselage in a faceted manner. This was calculated by hand by Skunk Works engineers. They didn't have the benefit of computerized physical modeling back then. They were able to reduce the radar visibility to a size about that of a bird (it's actually a little larger, iirc). My understanding with Zoltan is that he just looked birds flying at 500-600mph. He claims that he invented all this complex, custom gear accompanied by advanced-sounding jargon, but the US military dismissed it as hyperbole (which Zoltan is known for). The B-2 had the benefit of computer-aided physical modeling which explains it's lack of facets. The B-1 and B-52 also have low observability characteristics to reduce their radar and infrared characteristics (although they aren't known as "stealth" aircraft). I think that stealth aircraft as we know them are largely obsolete. Hence, the increased focus on UAVs and satellites. I have some ideas about where to go next, but the costs would make the B-2 look like a Girl Scout cookie sale. Disclaimer: I worked on many of the above-mentioned aircraft.

stratomorph 16y ago
>The B-1 and B-52 also have low observability characteristics I'd challenge the B-52 bit. The airframe had pretty well reached its final form by 1950. Radar was still in its infancy, let alone radar countermeasures. The plane is all radar-inviting angles (like the giant vertical stab), and there wasn't even an attempt to shield the engine exhausts from IR sensors, as IR homing weapons didn't exist at the time. I'd go so far as to say the B-52 is about as high-observable as an airplane gets. Edit: Maybe you mean active countermeasures?
- runjake 16y ago
  You are correct about the airframe, but the airframe wasn't what I was referring to. http://en.wikipedia.org/wiki/Radar-absorbent_material http://en.wikipedia.org/wiki/Radar-absorbent_material Active countermeasures aren't very stealthy except when you're attacking a specific detection system.
  - 16y ago

poi98u7y6tryuio 16y ago

So he used training and tactics - isn't that rather unsporting? I thought the idea was we only flew expensive aircraft against people living in caves (or at weddings) or at least stuck to bombing those with no anti-aircraft ability. Poor people shooting back at $Bn aircraft just isn't fair.

PostOnce 16y ago
Who said it was unsporting?

ajays 16y ago

Personally, I think this bit was the key: The Serbs had spies outside the Italian airbase most of the bombers operated from. When the bombers took off, the information on what aircraft they, and how many, quickly made it to Zoltan and the other battery commanders. My guess is, if you know how many airplanes are on their way and at what time, you can prepare. Knowing the ground speed, you can estimate when they're going to be above you and quickly light up your radar, take a pot shot, and then turn it off and scoot.

yread 16y ago

There was also this rumour going around that f117 can in fact be detected by passive systems Tamara and Vera. see http://72.52.208.92/~gbpprorg/mil/radar/tamara02.htm http://72.52.208.92/~gbpprorg/mil/radar/tamara02.htm

mjb 16y ago
Optimisation for stealth against bistatic and multistatic radar systems is a different problem from the monostatic case. The important thing is the split between the position of the transmitter and receiver. In the monostatic (transmitter and receiver in the same place) case, you need to optimise to reduce radar energy reflected back in the direction of the transmitter. When the receiver and transmitter are split, this problem gets harder, because you need to optimise to reduce radar energy transmitted back in the direction that recievers are likely to be (or don't reflect any, but that's a different problem). This becomes even harder in multi-receiver systems, and even harder in multi-receiver-multi-transmitter systems. As computation power and communication bandwidth becomes cheaper, lower power, smaller and easier to hide, many of the assumptions used during the development of the current generation (and past generations) of stealth aircraft are becoming invalid. Passive location systems, either secondary radars or systems using 'transmitters of opportunity' also reduce the effectiveness of anti-radiation weapons significantly. The radar vs. stealth arms race continues.