Northrop Being Screwed by the US Government

[vikingBerserker]

I believe the problems with the vibration was done away with when the duel props were eliminated and switched to the 4 bladed single ones (after having tried the single 3 blade). The reason why it was halted was due to the AF being more interested in the YB-49 version so the YB-35 order was amended to include the YB-49.

http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2583

I also know that the B-35s were equipped with guns and gun turrets, I believe the B-49 was the one not armed.

 

[davparlr]

[

]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.

 

[davparlr]

continuing

In summing up my opinion
1. From the beginning the AAF/AF favored and prioritized the B-36 over the B-35, which I think it considered a technological dalliance, probably because the B-36 was conventional and the B-35 represented a risk and possibly due to politics/corruption. Consolidated was a huge company with plenty of influence and Northrop was a little start-up. Because of this, tons of money were dumped on Consolidated that allowed them to solve significant problems, money that was not provided to Northrop to solve their problems.
2. The airframe itself was of sound design but had some design issues of stability, mainly in yaw but also a bit in pitch. The one-third size N-9M has been flown for many years and I do not think there is much concern about its flying qualities. GregP could address this.
3. The primary problem which caused major delay and prevent the obtaining of critical aerodynamic data was the gearbox and propeller, both of which was AAF/AF responsibility, not Northrop's. Had this problem occurred on the B-36, it would have been fixed.
4. Yaw stability could have been fixed (and probably was by the time the program was cancelled) with yaw damper/autopilot, so too, any pitch oscillations. Possible lack of trust in the newly evolving science of artificial controls may have caused the AF to ignore this.
5. Range of the B-36 and B-35 was initially predicted to be insufficient and both had been recommended to be cancelled. The B-36 was allowed to continue to develop to acceptable levels whereas, mainly because of government failure to perform in fixing the gearbox/propeller issue, the B-35 was unable to continue to develop.
6. Improvements to the bomb bay of the B-35 to allow for the atomic bombs would also have increased bomb carrying capacity, which was already 51,000 lbs of bombs. However, it is doubtful that the B-35 could ever carry the bomb load of the B-36. Then again, the B-36 never dropped iron bombs on anything but a target range.
7. Had the B-35 been supported by the AAF/AF to level of the B-36, it would have had a great aircraft with long range at a much cheaper cost than the B-36, by the time the B-36 was introduced.
8. The YB-49 was an anachronism and should have only been procured as a research aircraft as Northrop had expected. It would have been great as a vehicle to explore large jet powered aircraft and possibly open up advance RCS thought.
9. It would have been nice for Northrop to have reviewed German aerodynamic data post war and begin a ground up design of a jet powered flying wing. Hiring one of the Horton brothers wouldn't have hurt (he actually tried but the State Department would not approve). This plane could possibly challenge the B-52.

 

[davparlr]

I believe the problems with the vibration was done away with when the duel props were eliminated and switched to the 4 bladed single ones (after having tried the single 3 blade).

The single four bladed prop did not allow full use of the power of the engine.

The reason why it was halted was due to the AF being more interested in the YB-49 version so the YB-35 order was amended to include the YB-49.

The reason why it was cancelled was because the gearbox/propeller problem prevented it from performing as required. The YB-49 should have been an experimental buy. It was based on the propeller driven B-35, not a ground up jet like the B-47. It had no hope.

 

[GregP]

I have had several conversations with Ron Hackworth, the primary pilot of the Northrop N9M-B owned by the PLanes of Fame. He says it flies fairly conventionally with one exception.

When you come out of a turn with any decent amount of bank, there is no vertical surface to help out, so the aircraft yaws back and forth 7 or 8 times before damping out and going straight with no yaw oscillation. Like most of the Northrop wings including the B-2, the outer wing surfaces can split with the top surface deflecting up and the bottom surface deflecting down, acting like a rudder in that it causes drag at the wingtip. If you push BOTH rudder pedals, it acts like an air brake. Unlike most other flying wings, the outer surfaces on the N9M-B can not only split, but can also move differentially like ailerons. This serves as roll trim.

Ron says if he dances on the wingtip rudders, he can drop the back and forth yaw to 3 - 4 oscillations but, if you simply know what to expect and go with it, it damps out and flies very predictably. He feels that if this function was operated by a yaw damper, you would have a hard time telling you were flying a tailless aircraft.

He flies it as often as he can and it has a pretty full air show schedule around Southern California. He flew it last weekend and the one before, too. The engines are flat 8-cylinder Franklins of some 350 - 400 HP each, and the props are driven through torque converters very similar to the ones used in automatic transmissions. They are there to eliminate the vibrations caused by long driveshafts turning at aircraft rpm levels. In this, they succeed quite well and the plane is quite vibration free for a propeller twin. The pitch axis is quite conventional in feel.

If the XB-35 and YB-49 flew like this aircraft, and there is no reason to suspect otherwise, it could easily have been a good bomber since bombers are not usually flying steeply banked turns while on a bomb run just before they release the bombs.

 

[vikingBerserker]

The reason why it was cancelled was because the gearbox/propeller problem prevented it from performing as required.

That is not what the USAF says.

 

[gjs238]

Hiring one of the Horton brothers wouldn't have hurt (he actually tried but the State Department would not approve). This plane could possibly challenge the B-52.

Wow, what a team that could have been!
The US had no problem bring over Wernher von Braun

Edit:
> https://en.wikipedia.org/wiki/Operation_Paperclip
> https://en.wikipedia.org/wiki/Operation_Lusty

 

[davparlr]

Wow, what a team that could have been!
The US had no problem bring over Wernher von Braun

Yeah, interesting.

 

[davparlr]

That is not what the USAF says.

In a round about way, it certainly was a major contributor. The gearbox/propeller problem affect the program in several ways. The continual problems with program delays certainly soured the AAF/AF on the program to start with. Another one of the major impacts was that the aircraft could not fly enough to obtain aero data with the proposed system. Also, maximum performance could not be obtained without the counter-rotating props thus design performance could not be measured or verified. Had the problems with the gearbox/propeller not occurred or was corrected quickly and performance verified, enthusiasm may have been maintained and the issue with platform stability could be addressed with the autopilot/damper development. Remember, the B-36 was also having problems and was threatened with cancellation. Had the XB-35 been successfully and reliably performing flight test it could have swayed some votes.

 

[davparlr]

double post

 

[GregP]

We have had Bob Cardenas speak at the planes of Fame on several occasions. He was a primary part of the Flying Wing bomber program and says both the XB-35 and the YB-49 dlew quite well. He said it had some yaw damping issues, just like we see with the N9M-B, but that it could have been a good bomber platform.

He says the B-47 was probably a better conventional bomber as both were flown at the time, but that there was nothing preventing the YB-49 from being a good, if a bit slower, bomber. He says he might have preferred the slightly slower YB-49 and the lower radar return to the slightly faster B-47 but more easily seen B-47, but that decision was made well above his pay grade.

He DID say the main issues with the XB-35 were the contra-props that were GFE (Government Furnished Equipment) to Northrop.

Like all technologies that push the envelope a bit from past normal levels, both the YB-49 and the B-47 had some issues that had to be worked out in early service use ... but he saw nothing that could not have been rather easily fixed and made ready for service use. He is convinced that the YB-49 died from politics rather than from being unworthy or unfixable.

 

[FLYBOYJ]

Something about "GFE." Although the government may supply a component, in the design stage the government AND manufacturer will negotiate the use of a component. If there are "design issues" in the use of that component, the prime manufacturer has to determine a fix, if the component is not built well or has quality problems, the government has the responsibility.

I saw a piece about the P-38 where a former Lockheed VP tried to blame issues with the Allisons on them being "GFE." I'll try to find the guy who said this.

 

[davparlr]

Something about "GFE." Although the government may supply a component, in the design stage the government AND manufacturer will negotiate the use of a component. If there are "design issues" in the use of that component, the prime manufacturer has to determine a fix, if the component is not built well or has quality problems, the government has the responsibility.

I saw a piece about the P-38 where a former Lockheed VP tried to blame issues with the Allisons on them being "GFE." I'll try to find the guy who said this.

I wasn't too familiar with GFE as almost nothing was GFE on the B-2, except, maybe the engines (although the control units would have had to have been hardened). What GFE I was involved with on Tacit Blue was strictly government responsibility but, again, there was no development of those items. I can't really imagine a prime getting involved in a GFE design unless it was under contract to develop an item which would then become GFE. Maybe that was the case here. In any event, I suspect Northrop never had the funding or power to adequately address the gearbox/propeller issue if it was their responsibility. The problem was not insurmountable as the Russians proved on the Tu-95.

 

[FLYBOYJ]

I can't really imagine a prime getting involved in a GFE design unless it was under contract to develop an item which would then become GFE. Maybe that was the case here.

Exactly! In the case of the XB-35, I don't see Northrop being directed by the government to a specific propulsion supplier during the design stage (I could be wrong, just my opinion), but once the government gets involved, well....

This is from Wiki on the XB-35.

"In June 1946, the XB-35 made her first flight, a 45-minute trip from Hawthorne, California, to Muroc Dry Lake, without incident. The XB-35's engines and propellers were Army Air Force property, and had not been tested for engine-propeller compatibility by either Pratt Whitney, Hamilton Standard, or by the AAF which bought them at Wright Field without testing them or assuring reliability, and then shipped them to Northrop. Microfilmed records of reports and correspondence of the XB-35 program relate that after three or four flights, power plant and propeller vibrations increased, and the very efficient contra-rotating propellers began failing with frustrating frequency. Meetings were called by Northrop, of the AAF, Pratt Whitney and Hamilton Standard where no one would take responsibility for correcting the AAF's engines and propellers. In addition, the AAF failed to supply the AC electrical alternator, insisting on Northrop using unit powered by an automotive engine which limited the high-altitude, high-speed XB-35 to test flights below 4,600 metres (15,000 ft). The AAF also refused to allow Northrop proposed modification of the bomb bays to carry the standard Mk. 3 atomic bomb, while at the same time declaring the AF would not buy the bomber unless it could carry the A-bomb. Northrop reluctantly agreed to try a single-rotation propeller, which slightly increased takeoff distance and a reduced rate-of-climb and maximum speed."

 

[Shortround6]

Things changed considerably from WW II and just after to the present day (or even the 1980s). In the late 50s or early 60s many more contracts were written with one company (for aircraft the airframe maker) being designated the "prime contractor"and responsible for much more of the integration of the systems and even to writing the training and maintenance manuals which had, in the 40s and 50s, been the responsibility of the using service. Granted these older manuals were written with much input from the manufacturer but the government ( Army , Navy or???) had been responsible for final drafts, arrangement and publishing (printing and numbers of copies) which now the "prime contractor" had to do. It was series of problems like the ones that affect the B-35 that prompted this as the B-35 was far from the last program in which a number of manufacturers/suppliers and government representatives all sat around tables and pointed fingers at each other.

 

[GregP]

I worked for Motorola in defense electronics for 10 years ... mostly 1980's.

The government was responsible for all GFE. If they wanted us to fix a GFE design, that was a separate contract that was cost plus or we weren't interested in it. Also, the "plus" percent was slightly higher since we were fixing their problem. On such contracts, we had weekly reports due and regular design review meetings with the customer.

Sometimes we'd get to a point where the government would say, Stop. It's good enough right now." .. if we agreed, good. If not, we'd only agree if they signed an agreement that if more problems developed as a result of not pursuing a proper fix, the profit percent would go up considerably on any subsequent fix, and the government would waive any implications from delays caused by the new issues.

 

[Jugman]

Sorry for the Very late reply. Was very busy with work last year. Pretty much if I was not working I was sleeping.

On comparing different models.

December 27, 1942 1st N-9M
June 25, 1946 1st XB-35
August 8, 1946 XB-36
June 26, 1947 2nd XB-35
August 28, 1947 YB-36A (the example used for static testing)
October 21, 1947 1st YB-49
November 23, 1947 XC-99
December 4, 1947 YB-36
January 13, 1948 2nd YB-49
May 15, 1948 1st YB-35
July 8, 1948 B-36B
6 March 1949 B-36D

The B-36B made its first flight just two months after the only YB-35 to fly. This was not some prototype but a fully combat capable production machine. How is comparing the B-36B to the YB-35 and YB-49 not an apples to apples comparison?

On range.

The Manual can be found on this site.

http://www.ww2aircraft.net/forum/ot...-wings-xb-35-yb-49-yrb-49a-manuals-22818.html

This is for the first XB-35 in its original configuration. The charts are technically estimates.

A word on estimated range. The B-36 was originally estimated to have a range of about 10,000 miles. Over time this fell to 6,500 miles Xb-36 actually acheeved. Production models did exceed this but did so with a much greater fuel load than originally anticipated. The B-35 originally was expected to have a range of 7,600 miles. Based of the manual it dropped about the same percentage as the B-36.

The the main fuel system of the flying wings was only 5000 gallons. The auxiliary fuel system of the YB-49 add an additional 7752 gallons. The auxiliary fuel system for the YB-35 looks to be less than this (6000-6500 gallons?) per the parts catalog but I don't know for sure how much less. The bomb bay tanks were 895 gallons. The first YB-35 and the two XB-35s did not have the auxiliary fuel system nor did any of the B-35s have bomb-bay tanks.

If we use the XB-49 fuel load With six bomb bay tanks (18122 gallons) with a 10% +500 gallons fuel reserve, practical combat radius for the B-35 would be ~3200 n.mi. Weight would be ~215klbs with a 10,000lb bomb load. If you replace the outer wing guns with additional fuel tanks (another 3146 gallons) radius could be increased to ~3750 n.mi. with a weight ~230klbs. This would require more power and contra propellers to take-off at this higher weight.

On power plant reliability.

Both the B-35 and B-36 had the same vibration problem. Just of significantly different magnitudes. The problem was wing-propeller interference. The B-36 team lessened this problem by beefing up the trailing edge. The position and orientation of the propellers in addition to the greater trailing edge sweep made the problem much worse for the B-35. The duel rotation gearbox used a spur gear to drive the inner shaft/aft propeller with a bevel gear train to reverse the rotation and drive the outer shaft/ forward propeller. It was most likely the spur gear that was causing the mechanical failures. If the spur gear was replaced by the planetary gear train of the normal nose case, reliability may be improved enough to allow contra-propellers again. This will do nothing for the propellers though or the pitch change system. Felt vibration with the single propellers was actually worse than the contra-propellers.

On Bombs loads.

I do not know exact dimensions of the bomb bays on the B-35, but they were sized to carry 10 500lb GP bombs each. Six forward and four aft. The bomb bays were to narrow to carry a nuclear weapon. The bomb bay partitions were major ribs so there would need to be a major redesign to accommodate a nuclear weapon. Northrop's proposal was to modify the bombs to be slung semi-submerged in the bomb bay. The Air Force was not keen on the idea.

The conventional bomb load was not particularly great as compared to the B-36. It looks like bomb bays four and five could not carry 4000lb bombs or fuel tanks. Nor does it appear they could carry any thing larger than the 500lb GP bomb on their inboard racks. This means the B-35 had a maximum bomb load of 28 1600lb AP bombs plus 10 500lb GP bombs.

On stealth.

The story goes that a YB-49 flew towards a radar station and went undetected until it was "over head". Detection range decreases with the 4th root of RCS. So a 90% reduction in RCS yield only a 44% reduction in detection range. A 99.9% reduction yields an 82% reduction. The idea that the YB-49 achieved such a reduction with out RAM or purpose shaping of any kind is just ludicrous. The much smaller Ho 229 could not achieve this level of reduction and it was made of less reflective wood with primitive RAM in its glue. There is certainly a grain of truth to the story but the idea that Northrop managed to make a stealth aircraft by pure luck is just absurd. Radar of the time was to some extent open to operator interpretation. They likely mistook the YB-49 for something else.

On Van Zandt's "information".

It says right there on that very page that Van Zandt's "information" was fabricated By one Cedric R. Worth. Furthermore Sorenson points out that no one on the House Armed Services Committee, including Van Zandt, offered any evidence to contradict the testimony of Air Force personnel. Nor did any manufacturer, including Martin and Northrop, provide any evidence of any wrong doing. It's tempting to say that Symington was coercing others, but was he really in a position to do that? He was not anybody important in aviation or military circles before his appointment to Secretary. And he was only in office a little over a year when the decision was made. What kind of threats could Symington really carry out? None of the Secretaries had unilateral control over their service. Nor was the selection process opaque. Any kind of influence would be noticed. Does anyone really think the likes of Kenny or LeMay would simply kowtow to Symington?

On C/G and stability.

Let me correct myself. In oder for a flying wing -or any tailless aircraft for that matter- to really capitalize on their theoretical drag advantage their c/g must be rather far aft for the type. This is actually pretty far forward compared to a conventionally configured aircraft. I am not going into any more detail on this subject as there is plenty of information out there on both tailless aircraft and advanced flight control systems and the considerable difficulty encountered with them. I will say that from my understanding that the XB-49 probably needed a proactive system to completely eliminate its problems.

 

[Jugman]

part 2

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!

He did not quote the Time magazine artical he quoted Bill Gunston's book on the Northrop flying wings which quotes the Time article. I don't see anything wrong with the quote. As far as the "mysterious" handling characteristics I don't think he is referring to the control reversal problem but the generally poor stall and spin characteristics of the Northrop flying wings. The fact that there is an N-9M flying does not prove much at all. There are Sopwith Camel replicas flying as are examples of other aircraft with poor handling characteristics in flying collections.

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.

Actually he does mention the delays. He also points out that the decision to build more than the original contracted number of B-36s did not occur untill after the much improved B-36D was proposed. It is true that he does not go in to detail but such detail is not germane to the issue. The simple fact is the B-36 saw a dramatic improvement in performance in a little over two years.

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 distance record was set by the B-29. The fact that Northrop wanted to brake this record doesn't prove anything.

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.

To my knowledge the Air Force and Northrop never really had an official position on the crash. Northrop's position in their official history seems more like a dismissal rather than an explanation. It is by no means uncommon for a company to gloss over their failures. The circumstantial evidence supports the stall hypothesis. According to Cardenas he tumbled the first YB-49 after stalling it. Near the end of WWII the NACA free fall wind tunnel tested a scale model of the N-9M with the same results.

The taxi accident has photographs that support the USAF's position. That being said the two positions are not mutually exclusive. It may be that there was some damage to the nose gear at some point earlier that could have contributed to the accident.

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 don't have any details on program cost for the two aircraft, but what I have seen is not out of line considering the different scales of the two programs. The two contracts that cover the B-35s and the YB-49s ended up at just over 66 million dollars by the end of FY1948. This was just enough money complete the remaining 10 aircraft "as is". The first two B-36 contracts -which covered the two prototypes and the first 95 production machines and the cost to modify them into Ds and Es- had a value about ten times that of the B-35/B-49 contracts. Most of the money for both aircraft was spent on actually building aircraft. For the money spent Northrop had five incomplete flying examples and ten incomplete non flying examples and the four N-9Ms. Convair had 96 flying examples and the YB-36A that was used for static testing. 73 of these were fully armed and nuclear capable aircraft.


The B-35 was actually the preferred aircraft during WW2. It had less range but was expected to cost less to build and maintain than the B-36. Martin was brought on board to speed things up and to build the 200 production machines on order. By early 1944 it was clear that the B-35 -which was all ready behind schedule and over cost- would not make any contribution to the war effort. So the production contract was cancelled and Martin tooled up for B-29 production. This is when any chance of producing the B-35 died. The only way the B-35 would have been revived is if it demonstrated outstanding performance to justify the considerable cost necessary to cover the cancellation of the B-36 and the extensive modification needed to make the B-35 nuclear capable and fix the many problems that were never addressed.

The bottom line is the B-35 had more technical problems and of greater severity than the B-36, but no better range and could not practically carry bombs larger than 4000lbs. The only "evidence" of any wrong doing that has ever been presented is the falsified Worth paper and the claims of a very old Jack Northrop.

I am very leery of explanations that revolve around someone or group being corrupt, biased, incompetent, or what ever. These explanations are usually just a convenient way to dismiss contrary evidence. The whole Symington corruption explanation reeks of this.

 

[vikingBerserker]

very interesting!

 

[GregP]

Hi Jugman,

You said, "the XB-49 probably needed a proactive system to completely eliminate its problems."

A proactive system for what? Your sentence is unfinished ... do you mean a system for adjusting the C.G.?