Incident at Muc Wa

An interview with Robert Cardenas

[On July 21, 1996, I called Brigadier General Robert Cardenas (USAF retired) at his home and asked him about his experiences testing the Northrop YB-49 in 1947 and 1948. As a major, he was Glen Edwards's superior at Wright Field, and he was in charge of the YB-49 program before and after Glen Edwards. These are my notes of our conversation. In a few cases, when General Cardenas reviewed my manuscript for publication, he asked me to modify the phrasing, and I did so. Any errors in this transcription are mine; the ideas and phrasing are copyright 1996 by General Cardenas. Everything in brackets is my wording. I use asterisks (***) to show where I have softened an off-color word. -- Daniel Ford]

"I started the Military Phase II [test program] 13 Jan 1948. Max Stanley was the company pilot. I was the military Air Force test pilot. I did one stall and then wrote a report that as far as I was concerned the stall tests were finished and that the airplane should be placarded against any intentional stalls, period. And I never stalled the airplane again.

Part of the Phase II performance tests that the military runs is to determine the performance of the airplane. Then they do Stability and Control tests--Phase III--but first you gotta find out some of the very primitive beginnings: what's the takeoff speed, what's the nose wheel rotation speed, what's the stall characteristics, etc. So yes, deliberately I stalled the airplane, and I didn't like what the results were, and I said that the airplane should be placarded against any intentional stalls, period. Then on 20 May 1948 when I was oh, about 70 percent finished with Phase II, I had a chance to USC and finish my aeronautical engineering degree. My boss Col Boyd let me go, provided I could get someone to finish the tests. My co-pilot Maj [Danny] Forbes had not been through the Stability & Control ... school; he'd been only through Performance. So they had to get someone who was a graduate of the Stability & Control school, which of course Glen Edwards not only was a graduate of that but he helped Dr. [Courtland] Perkins of Princeton write the book on Stability & Control. So therefore he jumped at the chance to take the tests on from there, so I checked him out on the 20th of May, the 20th or 21st of May [1948]."

"Of course the internal configuration of the airplane was so lousy that the check pilot, to check somebody out, you couldn't really, all you had to do was to fly the thing because the co-pilot's seat was buried way down in front. I could tap the top of his helmet with my right foot.... The first time around [Glen Edwards] rode in the co-pilot's seat, just to get a feel for how the Wing felt--orientation, more. Then on the 21st of May he flew in the left seat and I went down in the hole... If you see the pictures, you see that the leading edge on the righthand side has some window panels, where the co-pilot sat. The pilot sat up in the bubble."

"So [Edwards] was checked out. He was a damned good pilot. I left to go to school [at the University of Southern California]. He made his first flight without me--he inherited my co-pilot--he made his first flight on 28 May. Then he flew with Danny [Forbes], I forget, five or six flights, about ten hours or so, and from what I knew they had started some stall approaches. I don't think they stalled the airplane, but they had started some stall approaches. That's all I know of what they did."

[Was it difficult to tell the attitude?] "I don't know who said that, but they're totally, they don't know what the hell they're talking about. I know where they got that from. You see, the pilot sits up in the bubble, way up in front, almost near the leading edge, so sure, if you change the attitude say one degree up, since you're right up on the leading edge, you feel like you've gone more than one degree. But it's not hard to tell, because you still have a horizon, and any pilot of any value can tell what the hell his attitude is, whether he's sitting up front or in the back. No, there was no problem with that."

"What happened to me 42 years ago, when I finished the tests ... I had someone from the Smithsonian, Air and Space Museum, come to interview me. Well, since he was coming from the Air and Space Museum, I figured the guy was highly technical in aviation and in aeronautical [engineering?], so I spoke to him in technical terms, and what I told him was that the airplane had demonstrated in flight marginal stability about all three axes, therefore resulting in a phugoid oscillation on recovery from maneuvers, which as far as a bomber was concerned, when you're turning onto your bomb run and you've banked the airplane and turned, and you recover and you get a little phugoid, it's not very nice for the bombardier squinting through a bomb sight. That's what I said. He put in that report that Major Cardenas said that the airplane was unstable. I never, never said that the damned thing was unstable. So from that time on, for forty years I refused to give an interview to anybody, media, nobody else. I just said to hell with it. I'm not going to be misquoted, mishad?, misinformed, I said nothing. It wasn't until about three years ago when I was asked to please allow Mr. John Honey to interview me and produce a television tape.... [Max Stanley also.] He produced a tape which I consider topnotch, and as far as I've got anything to say it is contained in that tape..."

"In 1946 I was sent out by my boss to fly the N-9M, the little two-engine pusher prop job, just to get a feel for the characteristics of a flying wing--which are different, because particularly coming in to land the C sub L is such that ... (illegible) that your have in other aircraft where your tail is back on a stick you might say. Landing the airplane is different because of the C sub L. In fact, one of the nice things about the Flying Wing, you don't have to worry too much; you stick your speed and fly it on down and touch, and if you look like you're going to be a bit long you shove the speed in on the rudders and you land."

"Anyhow, I flew the N-9M back in 46, August or September 46. So did Glen Edwards, and there were a couple other guys from Bomber Test Section, because at that time I was chief of the bomber section back at Wright Field."

A Vision So Noble

[General Craigie had written that the N-9M was so unstable in yaw that the company put a bit of yarn on the leading edge so the pilot would know if he was flying straight ahead] "I'm not trying to say that Craigie's stupid. Yes! We did have on the N-9M a string on the front end that would naturally, if you were yawing, it would bend over because it was in the airstream. Yes. Now! When are we talking about this? In today's world, 1996, saying that you had to put a string out there to tell which way you were going sounds primitive. But that was in 1946, 1944, that they had the string out there. That's before technology has given you everything else. So for its day that was as good as having the latest NASA boom out there. Again, you have to put in perspective. That's what destroyed me about this Smithsonian article that they wrote 42 years ago, back in 49."

[Recalling Wooldridge's book about all-wing aircraft] "I get so frustrated about talking about this particular issue. Ed, something like Ed Copeland [Ted Coleman] wrote a book. Wooldridge wrote a book. Now. Woodlridge and [Coleman], they had a pro-Northrop bias. The B-49 had gear problems, it had engine problems, it had fuel cell problems, it had all kinds of problems. In November of 48 I had to brief a board of general officers about the whole airplane from beginning to end, and Mr. Northrop was in the audience. He heard everything I said. After I got through saying, he stood up and he said, "Gentlemen, Northrop [has] a lot of work to do." But what was happening was that Northrop was trying to sell an airplane--the company, not Mr. Northrop. Mr. Northrop was a gentleman and a genius in design, and his concept was correct, as has now been proven with the B-2. But I told those general officers, I said, "All of these mechanical and design deficiencies in the airplane, they can be fixed. I have no doubt that Northrop can fix these deficiencies." I said, "There are several that I don't know how they're going to do it." Because you couldn't get out of the airplane. We didn't have seat ejection; that hadn't been invented yet. We didn't have computers, so there was no fly-by-wire. We didn't have any of those things. As a test pilot the only thing I had was a 2H pencil, a knee pad, and a stopwatch, period. But I told 'em: "Those things can be fixed, but gentlemen, the one thing that I can't even begin to tell ya how to fix is the fact that the airplane needs some form of stability augmentation. I am not saying that it is unstable; I'm just saying that it needs some stability augmentation. I cannot tell you how or with what. The airplane has basically exceeded the human sensory and response capabilities."

"Now, Northrop got Honeywell to build an autopilot for the airplane, for the bomb runs--which were miserable. Now, an autopilot is like a human; a human, you are reactive to any sensory input of any kind. The human body reacts. The autopilot is also reactive. It reacts possibly with more precision than the human, but it's still reactive. What you needed was something that was proactive, something that was faster, that could sense what you couldn't sense. The B-2 has it."

[Colonel Albert Boyd, head of Flight Test Division in 1948] "He was the father of flight testing, no question. Bullet Boyd! He was our favorite. He was tough, he was stern.

[Commenting on Gary Pape's book about the Northrop Flying Wings] "Now, Gary Pape's book is the only one--it's got one mistake in there. He has Glen Edwards still flying the airplane on 25 June when actually he got killed on the fifth of June... He did a real good research job on the Flying Wing program... All the rest of 'em was based on mythology, wive's tales, and a bunch of other stuff."

[On Ted Coleman's accusation that the Air Force pilots did not seek information from Northrop employees] "That is a bunch of bullshit! I used to spend weekends up to Big Bear Lake with Max Stanley, waterskiing, talking about the airplane. That again comes from [Coleman] and [Wooldridge] who were . . ." [I missed something here]

"Northrop wanted to sell this airplane and stick it up the military's ass without vaseline, pardon my vocabulary. But that's the sum and substance of it. They didn't give a *** what the airplane could do or couldn't do or anything else. They wanted to sell it. It was not an operational bird. The cockpit layout was miserable. The crew could not escape if anything happened in the airplane--you couldn't get out. I never wore a chute, because I couldn't have gotten out anyway. You got in from underneath, a hatch underneath the airplane; walked about 15 feet forward, put your rear end in the seat, pulled one handle and rotated the seat ninety degrees in the line of flight, with the other hand you pumped yourself up four feet into the bubble--a bubble which could not be opened, could not be blown off. The only way you could get out is rotate the seat, lower it four feet, get down on the walkway and walk back 15 feet. In the event of an emergency [here Cardenas laughed] you couldn't get out. The cockpit layout was horrible. The bomb bay doors--the first time I tried to open them they sucked off. They blew off the airplane. The landing gear were still from a propeller airplane. It was unacceptable."

[Landing gear?] "Okay. The rate of acceleration of a jet aircraft once it is in the air is much faster than that of a prop job. You pick up so much airspeed so rapidly ... You had two choices on takeoff. If you took off what you might say normal you'd blow the gear doors off, because they did not--you see, this was a conversion from a prop airplane, the XB-35. ... When they converted it they changed the engines but they didn't change much else. So the landing gear took too long to retract. So I had to pull up, fairly steep, not real steep. The only other thing I could do is pull back on the power, but no sane pilot wants to pull back the power on the takeoff. So I left the power on and pulled it up to keep the airspeed down till all the gear came up. Then when you leveled off you'd sit there rocking in your seat back and forth in unison with the slosh of the fuel going back and forth in the fuel cells--no fuel baffling." [When he reviewed my manuscript for publication, General Cardenas hedged this phrasing a bit]

[In the Discovery Channel TV program] "Mr. Honey kept asking me, "Wasn't it a crime the project had been canceled?" And I kept telling him no. It wasn't a crime it had been canceled... This airplane, its systems had to wait for technology to catch up. And I couldn't have said a truer statement, because the technology has caught up, and we have the finest airplane in the world flying around in the B-2. Technology caught up with it. Not just the Stealth [feature but] the engines, the seat ejection, the fuel cells, the operational layout of the cockpit. Everything that was wrong with the 49 has been fixed in the B-2. The real crime would be now that we've got such a bird that Congress doesn't allow them to build any more. It's the finest weapons system in the world right now."

"But anyhow, the B-49 was not an operational weapons system. And we as military pilots were testing the thing as a military operational system, not as something--the company pilots, they were testing it to sell the airplane. Max Stanley and I never had any differences. Woolford was all wet!" [I think he means Ted Coleman here]

Remains - A Story of the Flying Tigers

"Prior to the B-49, prior to 1947--well, let's take the B-17. Boeing built the B-17 and gave it to the military and said, here's what you wanted, and the military had to find out how to use what the contractor gave them.... The original B-17 that was over there in Hawaii that got blown up, was not very good. Same way with the P-51. The B-24 also. The C-47. [They were all honed into fine aircraft.] So there's nothing wrong with a contractor building something and giving it to us to use. But for every shining example that you can think of, I can give you twenty of real crummy airplanes--not crummy from a design standpoint, but crummy from the standpoint of military operations. So somewhere, in 46 or 47, they changed things, and from that day onward the contractor flew what was called Phase I. All they had to do was prove it was airworthy. Then they turned it over to the military to do Phase II, which was Performance.... So the first few airplanes in which the new system came in created a controversy because the contractor, his main thing was to build an airplane and sell it. The military were testing it as an operational airplane. And so the controversy that arose was not between the pilots [but] between the military program office and the Northrop sales staff, engineering staff, etc. But the B-49 and its configuration in 1948 was not a military operational airplane."

[Danny] "Forbes knew everything that I knew. In fact, he was with me in my first stall, which resulted in a gyration that was abnormal. [The sucker flipped over.] And I wouldn't stall the airplane again. Forbes knew that. The company as a matter of fact, I guess it was after my stall, I guess they had to prove that it could stall normally, they hired a guy by the name of Charlie Tucker to do a stall series on the airplane. I met him one day and I said, "I understand you stalled it." And he said, "Yeah--and you were right, Bob.""

[Gary] "Pape has written what I consider now to be the Bible, with one major mistake and a couple of minor ones."

[Ted Coleman's book] "Okay, there were a lot of coincidences there [with respect to the activities of Sgt William Cunningham]. But nobody in the military ever said, Destroy this airplane. It's ludicrous. It's just sheer lunacy to say something like that. [that Cunningham sabotaged the YB-49 on Cardenas's return flight from Washington DC] The fact that I said Go get him and bring him up, he's going with us, that didn't mean I mistrusted him. [His voice does not indicate great trust.] It's just that, I don't carry a rabbit's foot, but I still felt that he was part of the crew and he should go with us. I had no other intent in that."

"The Wing, once they developed stability augmentation systems, which you do have, you now got a wonderful system. And some day, some company is going to build a large flying-wing cargo airplane with the stability augmentation systems to haul not so much passengers as cargo--lots of cargo--because the load is distributed along the span of the wing... During that movie [Honey video] it says there that during the last days of John Northrop he received a letter from [NACA NASA advisory board?] saying they were taking a second look at the Wing... They didn't call it a Flying Wing, they called it a transverse loader. As a matter of fact, the government gave a $1 million contract to three companies--Boeing, McDonald Douglas, and Lockheed--for a concept on a Flying Wing cargo airplane. They called it a Transverse Loader. You can take a huge airplane carrying a million pounds of oil or any other commodity, and you can land it on 3,000 feet because of the C sub L. You don't have a high rotation. You have a low speed, high rotation, and get something that can go 500 miles per hour, probably about a Mach 0.8, somewhere in there, and get the cost of moving cargo down below three cents a mile."

"You take the other plane I flew in combat in Vietnam was the F-105. When you came in in the approach in the 105 you had 200 knots approach speed and when you got within 400 feet or so of the ground you started your rotation, pulling the nose up--the flare, as they called it. That was mainly to increase your C sub L because you had such a high wing loading. Well, in the Flying Wing, although you were carrying a huge load, you had a very low C sub L to begin with, so you don't have to rotate the airplane, and you can come in at a much lower speed. So it'd be a beautiful bird for something like that [cargo]."

[YB-49 difficult to land because of ground effect] "Again, whoever said that never flew the airplane. I have said, and maybe they misinterpreted that, I have said that the hardest part of flying the airplane--and I was taking a lot of things into consideration--was to land it. Now that doesn't mean it was hard to land. You just had to get used to landing it because yes, the ground effect would hold you up. You could come in power off and as you approached the ground effect would tend to keep you up. All you had to do was shove your rudders in, both of 'em, at the same time. [ie deploy the drag rudders on both sides] It was a drag device. In fact I've won a lot of money out there at Edwards on bets regarding on wheter I uld land on this line. They didn't believe. Well, I could wait, since you sat up in front you could see where that line was, so as soon as I saw it approaching the ... nose of the Wing, I just shoved both rudders in and touched down. I didn't slam it down, I greased it down. I was just trying to tell them [writers?] that there was something a little different in the ground effect with the C sub L that was the only really difficult part of flying the airplane. It took off by itself, it flew beautifully--I could outturn fighters as far as that goes. It's just that it needed, under certain conditions, stability augmentation."

[I ran out of memo pad at this point. He went on to say that a John Benjamin of LA helped fund the restoration of the N-9MB at Planes of Fame in Chino. It consisted of the metal parts of the wing; the wooden parts most gone. In a junkpile in a suburb. Started rebuilding in an industrial park. Northrop declined to help. Former Northrop employees donated their time to work on it. John Myers, company test pilot, and Max Stanley (and Cardenas) advised on it. Truck to Chino. Engines and props found. Bruce Hinds and Don Lyken participated. Installed Franklin engines. Said they were five (fifty?) years old. Cardenas advised the pilot, John Stackworth, to be restrained because of its flight characteristics and the danger they posed if one engine went out. "I did not use the word tumble." He flew it very conservatively the first time around then got more daring. Cardenas has a great photo of the ramp up to the B-2 hangar at Edwards South Base with the N-9M in front of it. It has flown to Edwards and to San Diego (currently). Passenger seat to be removed and extra gas tank installed.]

Question? Comment? Newsletter? Send me an email. Blue skies! -- Dan Ford

the Glen Edwards diaries

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