[
]For some issues yes. Others no. Stable Flying wings have naturally high trim drag. This negates most of their theoretical drag advantage. They must be flown with a fairly aft c/g. Too far aft for anything but a computer controlled FBW system to handle.
I am not sure about this. I have no data on cg but the cg must have been ahead of the main gear, which was about halfway down the length of the fuselage (what there is of it) and the wing sweep could certainly be, and probably was, made to have an appropriate center of lift to provide a stable pitch axis. Porpoising is not an uncommon issue with stable aircraft. Yaw stability is a different issue and probably needed a yaw damper, which came available after the war. As for flying wing drag, I am not sure about this either since wing twist is also common to many aircraft. I am pretty sure that that wing modification drag would not be more than that humongous empennage on the B-36! I have seen this and believe me it is stunningly huge. See pix courtesy of wikipedia.
Just today I found Dr. Francis J. "Bud" Baker's Dissertation:
I did read this and while well researched, seemed not to address the entire story only emphasizing the negative aspects of the flying wing such as quoting a Time magazine article saying of the N-1M "it looked like a ruptured, weather-racked duck, too fatigued to tuck in its wings". While the author does go on and says the plane had a highly successful flight test program, what was the purpose of quoting a news magazine? Another quoted report on a crashed N-9M stated "subsequent investigation pointed toward dangerous and mysterious handling characteristics at low speeds". Which is okay but the author failed to mention that Northrop examined the aircraft and applied a simple modification to the others and no other "mysterious handling characteristics" occurred. In fact, the sole remaining N-9M is in flyable condition and is flown regularly at the Planes of Fame Museum in Chino, Ca. and has been doing so for many years!
Comments were made on the excessive delays that affected first flight while the author makes no mention that similar delays were occurring on the competing B-36.
Also, comments about disappointing range base on the 1944 memo seemed offset somewhat by the later notes stating Northrop wanted to break world records for speed and distance, but was turned down by the AF because of immaturity of the B-35, which was, undoubtedly, wise. But, apparently Northrop had faith in the XB-35.
The most critical and persistent problem as stated by the author was related to the gearbox and propeller but fails to mention that these belonged to the AF and they were under the obligation to provide satisfactory performance and they seemed unwilling to adequately address the problem. I suspect had the B-36 run into this type of problem, it would have been fixed with highest priority. Northrop was trying his best to get the AF, Pratt and Whitney (gearbox), and Hamilton Standard (propeller) to work at solving the problem but to no avail. Without this dual propeller set up, the full power of the engines could not be used.
As for as the YB-49 is concerned, I did not have a lot of disagreement with the authors position. Early jet engines were fuel guzzlers and suffered limited thrust. Also, the YB-49, based on the propeller powered XB-35, was not designed for the speeds that could have been achieved with jet engines. Sweeping the wing angle more, using a low drag airfoil, and using better engines, in other words, designed as a jet to start, the B-49 might have exceeded the performance of the B-47 in speed and range. As it was, it was only 80 mph slower in its obsolete propeller based design form. This and its inherent low RCS form may have begun an entirely new direction in bomber design and low RCS research.
As was, the B-47 was clearly the better design even with its shorter range.
The author quotes a comment saying "Therefore, it is felt that unless the B-49 can modified to carry the atom bomb, further procurement is unwarranted." But he failed to mention that the AF refused to allow Northrop to do this.
The author always seems to accept the Government position, especially on the accidents. While the crash of the B-49 was tragic the cause was and is, unknown. AF nor the contractor will accept responsibility for an unknown crash. So too is the taxiing accident. Test pilots are not prone to admitting mistakes and neither is the contractor. He said, she said.
Loss of an aircraft during test was not particularly unusual during this period including the B-29.
A lot was said about late testimonies from Jack Northrop and Tom Jones denying any problems with politics. However, I think that you would find that people whose companies are on the line tend not to be critical of the people in control of their contracts. Northrop himself said he lied during the testimony and stated why. I do not think this is surprising. Tom Jones himself was not above stretching the truth, or law, in making a profit for his company. He was convicted in Federal court for bribery with the South Koreans. People like Symington had life or death power over defense contractors and there were (and is?) a great deal of incestuous relationships.
The author makes no comparisons between the B-36 and the XB-35/49 in regards to the amount of funding each program had received. I suspect the B-36 was a massive development program that absorbed almost all development money (even from the Navy).
I have read the shorter article but not the Dissertation. The Dissertation is very well sourced though.
Of course this kind of repeats the issue above. I do have an additional problem with his comparison to the B-2. I was on the B-2 proposal team and was the Avionics Controls and Displays manager through the entire development effort. I didn't see many of the problems pop up that affected the flying wing program. From the beginning, the program was well financed to alleviate problems. Facilities were costed and paid and/or provided to do the development and manufacturing. Issues on stability and performance seemed non-existent because of flight control computers and wonderful engines. We certainly did have issues on RCS, avionics development and integration, hardness, unique environmental requirements and programmatics. But, except for programmatics, these where pushing the state of the art, which is always time consuming and costly. The B-2 development was not out of scope of other modern aircraft. The stealth ground breaking and highly complex B-2 took 19 years from go-ahead to introduction; the much simpler F-22 took 14 years, the F-35, 14+years, and the V-22 24 years! The problems with the B-2 were overcome by commitment of the supplier and the government. In the B-35 case I do not detect a real commitment by the government in effort or money to correct the issues.
As for the honesty of Government/supplier relationship, President Eisenhower stated,
"In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the militaryindustrial complex. The potential for the disastrous rise of misplaced power exists and will persist."
There was a reason he said that.