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Maj. Gen. Carlsons briefing on Stealth Fighters, Tuesday, April 20, 1999

Presenters: Maj. Gen. Bruce Carlson, USAF, Director of Operational Requirements
April 21, 1999 12:00 PM EDT

Subject: Stealth Fighters

Major General Carlson: I understand there's been some interest in the loss of the F-117 that we've had in the area of operations and some interest in the capabilities of our stealth airplanes, the F-117 and the B-2. And some interest in general in employment concepts that we use for those airplanes. I'd be glad to talk about those. I've got about three slides here to run over with you.

The F-117 and the B-2 are still being employed and will be for some time to come. And because of operational security and the safety of our air crews, I won't discuss specific operational details or tactics or targets. But I'd like to spend just a couple of minutes with you and talk about stealth airplanes.

We started out a long time ago building airplanes that had low observable technology incorporated into their design. The SR-71 was an example of where we took the aerodynamic design and then added some radar absorbing material to the airplane to make it slightly stealthy. And I'll give you a representation of that graphically here in a minute. We went to the second generation of airplanes and you can see we designed that airplane, the F-117, essentially from the bottom up to be stealthy. It was crude technology. It was developed at a time when we didn't have the modeling and computer power we needed to make the kind of aerodynamic design that we would have liked, but we built one that we thought was very stealthy. And of course, the night that Desert Storm opened the quote from Col. Al Whitley still is famous in the Air Force: "Boy, I hope this stuff really works." And of course, you know that it did. That isn't exactly what he said.

Then we came to the third generation of stealth airplanes. We built the B-2. And of course, by that time, we had the modeling tools and the design tools and the computing power to make an aerodynamic design that was optimum. And this airplane is [a] much higher altitude, much better performing airplane than the F-117. We were able to eliminate a lot of the radar absorbing material from the structure. And by the time we got to the fourth generation, we were able to add supersonic speed, the agility of an F-15, F-16 class airplane and do that with no degradation to the stealth. In addition to that, we were able to add a number of apertures, in other words, openings in the airplane's surface for antennas, radars and other sensors. And in the F-22, as an example, there are over a hundred of those apertures on the airplane, where if we jump back a couple of generations to the F-117, there are essentially a couple of aperture openings and the rest of them we hide when we go into combat.

Next chart.

This next chart gives you a summary of the kind of capabilities that we expect from our airplanes. Now, if you were doing vision and each one of these diagrams a surface-to-air missile or a radar at the very center, and in this case, one sitting on the top of a hill given the perfect view of the area around it, that would be considered its envelope of operation, its lethal range if it were a surface-to-air missile. When we take a conventional airplane and run it at that surface-to-air missile an infinite number of times, we develop a pattern of its susceptibility to that radar or that surface-to-air missile. And so you see, because of the shape of the airplane and the radar interface with the airplane, that's the sort of pattern that we come up to.

Now, in our first generation stealth airplanes, we focused the low observable technology in the front quarter at certain frequencies on the radar spectrum, mostly in what we call the target tracking or X-band area. That's the area that SAMs normally do their target tracking in on airplanes like a MiG-29 or an F-15 have their air to air radar in. So that's where we focused our work. And you can see there's a slight degradation in the capability of that SAM as that airplane is coming toward it. You notice, however, in the back, it's about the same area. Now, when we get to an airplane such as the F-117 or B-2 where we design it from the bottom up and use shaping optimally to lower its signature, we get a significantly reduced signature. It's not invisible. It never has been invisible. We know radars that can track our stealthy airplanes. They can sometimes find us. The key is that that zone of detectability or lethality is shrunk by orders of magnitude, but it's still not invisible.

Now, what does all that lead to? Our goal is that on the first day, we can, because we've shrunk those zones of lethality, find our way into the target area using good, detailed mission planning without being susceptible to either enemy radars or their missiles or their airplanes.

So, that's sort of my story. And I'd be glad to answer any questions that you might have.

Q: General, could I ask, number one, have you determined whether or not the F-117 was shot down? Number two, there was some talk about Yugoslavia shipping parts from the F-117 back to Russia to study. Are you worried about losing what amounts to 20-year-old technology there? And if so, why didn't you bomb the wreckage to pieces so they couldn't use it?

A: I think you had four questions there. I'll try to answer them in order. First, we have lost about seven F-117s over the course of the program, which is about 18 years. We consider this essentially the seventh loss. We have an investigation. We have completed the first phase of that investigation. The second phase is ongoing. We have not determined the cause of that loss. We have eliminated an act of God and loss of consciousness by the pilot, but we haven't determined the cause of that loss. So we are fairly confident that in this case, we do know what happened, but because of the fact that this is an ongoing operation and we do have these young men flying into harm's way each night, I don't think it would be appropriate for me to talk about the results of that investigation any further.

Now, I think your second question was if they shipped the parts to Russia, would that concern us. Sure, it concerns us. We don't like to give anything away. I think we're just as protective of our technological advances as anyone is. However, if you go back to that first slide, that was what we called second generation stealth. And we've put a lot of distance between second generation and the airplanes that we're building now. We think that the result of that material, should it have gone to Russian hands -- and you'll have to ask Gen. Wald about that. I'm not sure what operations went on over there at that time. But if it went over there, we think that the loss is minimal.

And then third, why didn't we bomb it. This was one of the last sorties of the evening for the F-117s. It fell in a -- the airplane was lost and crashed in a rather remote location. It takes time to find those things. And I'm not sure that the commander in the field felt it was worth the risk to go in there and try to bomb it. But again, that's probably a question for Gen. Wald.

Q: General, I'm confused by the answer to that first question. Are you saying you don't know if it was shot down, or are you saying that you're not prepared to tell us for security reasons if it was shot down?

A: What I am prepared to tell you is that we are fairly confident we know what happened that caused the loss of this airplane. But because of the fact that this is an ongoing operation -- I'm concerned about the safety of the air crews -- I'm not prepared to divulge it.

Q: Now, for the B-2, it has a small signature, but it has a signature. Now, in Kosovo and in Serbia, do the Serbians have the capability of tracking by radar the B-2? And a second question I was kind of curious about, all these planes are putting out heat and quite a bit of heat. Can they be tracked by infrared?

A: In answer to your first question, can the F-117 or B-2 be tracked by radar, the answer to that question is yes. All vehicles can be tracked by radar. However, the key here is to know when you're being tracked by radar, what radars are tracking you and what the fidelity of that track is. For instance, a very low frequency radar has very little ability whether it's tracking a conventional, first- generation or a third-generation stealth airplane, has very little capability to track it with precision. They know the general area that the airplane may be in, but they can't track it with precision needed to guide either another airplane to it or a SAM to it. So what you need then is the target-tracking radars, the higher frequency radars that are much more accurate, and that's where the stealth airplanes that are designed from the bottom up have their significant advantages.

Now, in terms of infrared signature, certainly they give out heat. We have minimized the signature, the infrared signature on both the F-117 and the B-2, so it's significantly less than, for instance, an F-16, which has a round tail pipe that sticks out the end. Each of the exhausts has been designed to minimize that signature. We fly them at altitudes and in conditions at night where infrared tracking has very, very remote chances of detecting them.

Q: General, how would you assess the performance of the B-2 in these operations?

A: I think the B-2 is performing superbly, but probably that's a question for Gen. Wald.

Q: General, can we just ask you about the -- to what extent -- I mean, you talked about any compromise in stealth technology being minimal, but to what to extent and what value is there, can any of these things be reverse engineered or are there still parts of this that are secret that could help countries, whether it's Russia or any other country, develop their own stealth technology? Or can they learn anything about it from the wreckage of the plane that helps them defeat stealth technology?

A: As I said, we don't like to give anything away. We think that the damage, if parts of the airplane made it Russia, is minimal. I would just tell you this: The science involved with making an airplane low observable is not a secret. It involves shaping and radar absorbing material. The technology needed to make radar-absorbing material is available in a number of places. However, the manufacturing capability and the art of putting one of these airplanes together demands exceptionally close tolerances and highly skilled people. It has been our experience from looking at the other airplanes that we've seen developed and produced and fielded throughout the world that we are probably the only ones right now that can field this kind of technology.

Q: Just to follow up, Russia recently, I believe it was either earlier this year, maybe it was late last year, unveiled a plane that they said was a prototype of a stealth aircraft. Later, many aviation experts said in fact it wasn't a stealthy aircraft at all. Does Russia have any (inaudible) capability and was this fighter plane that they unveiled, in fact, any kind of stealth aircraft?

A: Well, I'm not an aviation expert. I'm just a fighter pilot. I haven't seen the airplane. I've seen pictures of it, and it certainly doesn't look like a stealth airplane to me.

Q: General, why isn't the B-2 forward deployed? Is it a question of maintenance, fragility? And doesn't that cut down on its combat role?

A: I don't know specifically why the CINC has decided to keep the B-2 here and staged out of the United States. I know that we have flown a significant number of sorties, and the airplane has done very well. You'll have to ask Gen. Wald if he has a comment on that.

Q: General, on the 117, have you been able to rule out the possibility that the VJ forces received advance information about that aircraft's flight?

A: I don't think I should comment on any of that.

Q: General, where does the B-1 fall in this category? Is it a second generation or first?

A: The B-1 would be a first generation airplane.

Q: General, in a briefing about 10 years ago on stealth, we just want to see if it's still relevant to Kosovo and other Soviet designed defenses. The rationale was that with stealth, by the time air defense station number one spotted you, he didn't have the computerized air defenses so that he could warn station number two to zero in on the airplane as it penetrated. In other words, the penetration ability of stealth was especially advantageous because the Soviet-made air defenses didn't have the computerized technology they needed to zero in on you right after you went from station one to station two to station three. Is that still the case, or is the Soviet-made equipment in Kosovo and other places since been computerized, they got rid of the vacuum tubes and therefore, that penetration advantage is no longer relevant?

A: Well, I'm not specifically familiar with what kind of equipment that they've upgraded in Kosovo or the FRY. But I do know that they are very capable. They are highly trained. They work very hard. They're highly motivated. So they present a very credible threat.

Q: General, in a place like Kosovo where we understand SAMs are being moved around quite a lot, do you ever get the kind of battlefield awareness that I think was on an earlier slide you showed us where the pilot would know exactly how to maneuver around the sites and have some assurance that he wasn't being tracked? And if you don't have that, are these folks flying with Prowlers or F-16 CJs to keep them safe?

A: We routinely package these airplanes with the suppression of enemy air defenses, both in terms of electronics and kinetic. In other words, we have HARM shooters, people that shoot high-speed, anti-radiation missiles. We also employ a number of intelligence assets in the field in the air to make sure they have the situation awareness they need prior to executing into the target area. So we keep them as aware as we possibly can.

Q: General, I understand that you're not going to explain what brought down the F-117 that was lost, but you did rule out a couple of general things, act of God, loss of consciousness by the pilot. Can you tell us whether this was not a result, for instance, of mechanical malfunction or some accidental factor, but, however, it was brought down was part of the hostile environment it was flying in?

A: We haven't ruled out some mechanical, some particular mechanical things, but the investigation is still ongoing, so I don't think I should comment any more.

Q: Last year, it was reported that Iraq was covertly trying to purchase an electronic warfare system from the Czechs called Tamara. Apparently, this thing has a way of triangulating, and it's reputed to be able to detect stealth aircraft. Are you concerned that Serbs may have some of this equipment, or do you see this as a future potential for neutralizing the benefits of stealth aircraft?

A: First, in particular comment to your question about that specific equipment, I'm not aware that the Yugoslavians have that particular set of equipment. Second, I'm not aware that the Czechs have been able to demonstrate that theory. And third, as I've stated before, airplanes, whether they're first, second, third or fourth, can be tracked, can be detected. The question is with what specificity and to how much detail you can track them and whether you can maintain the track. So, certainly, if someone after 20 years of us having stealth is able to invent something that would degrade in any way, and we're concerned about it, and we keep our eye on those things. But I'm not concerned that that's going to change the direction we're moving.

Q: Do you have any operational sensitivity -- do you not anticipate that when -- will you ever tell us as long as this conflict is going on what happened to that F-117 or will you wait until after the operation?

A: I would imagine that we'll wait until our kids are out of harm's way. And then if we think that there's an operational advantage to not telling you, we probably won't tell you.

Q: One of the curious things about the loss of this aircraft, assuming that there's a high probability that it might have been shot down in some ways, why in this whole conflict with thousands of sorties, the only plane that apparently has been brought down is the stealthy F-117, which in theory, should be one of the hardest planes to bring down? Any thoughts on why that could be the case? Why hasn't any other plane been shot down?

A: Well, if we determine that it was shot down, we'll work that question awful hard. As I've said, we've lost seven airplanes in the past out of our fleet of -- I think we built 64 of them. And we're concerned about all those losses. We've taken steps in each case to investigate those losses in a great deal of detail. And in those cases, in the past, we've made changes to the design, changes to the cockpit, changes in training. And we will continue to do that with this loss.

Q: Just to clarify, all the previous losses you're talking about were accidents, is that correct?

A: Yes.

Q: (Inaudible) you say changes have been made. Without compromising security, can you say anything about any operational changes that have made regarding the F-117 to prevent this from happening again?

A: For the accidents in the past?

Q: No, this one, during this operation.

A: No, I won't say anything about operational changes we've made.

Q: Excuse me, General, you did say that some particular mechanical things, you haven't ruled out some particular mechanical things. Have you ruled out whether it might be the type of accident that occurred at the air show with the parts just started coming off the plane, and it went into an uncontrolled spin? The Baltimore air show, have you ruled that out?

A: No, we haven't ruled that out.

Q: General, sir, you mentioned that the point of stealth is to make it less observable to X-band, but it could still be visible or detectable on low frequency radars. Is this the case where you ran into multiple low frequency radars, and they were able to get a reasonable fix on it? Is that what happened?

A: I don't think I should comment on that. I kind of stated that up front.

Yes, sir.

Q: To what degree are radar absorbent materials used on the F-22, and are they of similar sorts that were used on the F-117?

A: Just by way of comparison, the F-117 is completely covered with radar- absorbing material, and this airplane has a very small percentage of its surface covered with radar-absorbing materials. And the materials are, if these are second generation, then these are fourth and fifth generation. In fact, as we are developing the airplane, we have made changes in the materials themselves, mostly due to reliability and maintainability considerations. We just want to make this as easy to maintain as an F-15 or F-16 is on the flight line.

Q: General, we were told during -- that some aspects of the F-117's flight such as when the bombay doors are open or when it's engaged in a banking maneuver or something, that its radar signature might be a little greater. Could you just explain why that is and how that works?

A: Sure. I've flown the airplane before quite a bit. Let me just first say that when the doors open, there's no doubt in your mind they're open. They're about twice as big as that door that you see coming in the room over there, and there are two of them. So if you're at .85 Mach and the doors open, it gets your attention right away. When they close, there's no doubt in your mind that they've closed. In addition to that, there's a series of indications within the cockpit that tell you that. Now, just as we designed the airplane to its shape to reflect radar energy away from the receiving antenna, as soon as you put out a couple of big, flat plates that are twice the size of that door, you invent instantly a radar reflector. So that explains, I think, how come the signature increases. What we've done after we begin to fly the airplane operationally is significantly decrease the time that it takes for the door to open, the bomb to come off and the door to close so that that time is very, very small now.

Q: How is the B-2 holding up? Most of us were with you August a year and a half ago watched you give it a bath. And I know that you have improved the coating on it. What has this operation taught you? What has it shown you about the maintainability of the B-2?

A: The B-2 continues to improve in its maintainability. In fact, two of them landed the other day at Whiteman in the driving rain, and they had flown 30 hours. And the LO [low observable] maintenance was essentially routine. In other words, there were no major LO write-ups or no hits on the airplane that would have kept it from flying immediately thereafter. So we think we're turning the corner on low observable maintenance on the B-2. And I think it has great potential in the future. It's doing superbly over there now.

Q: Thank you.

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