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. -- Dan 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."

[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 wrote a book. Wooldridge wrote a book. Now. Woodlridge and Copeland, 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 Copeland and [Wooldridge] who were . . ." [I missed something here]

continued in part 2