No one dared to ask his business no one dared to make a slip
For the stranger there among them had a big iron on his hip
Marty Robbins (Big Iron)
In the early 1950s our big iron was the Convair B-36 "Peacemaker", which bore the same name as Colt's legendary revolver.
(Plus I've had that Marty Robbins song stuck in my head since I started playing Fallout New Vegas)
Convair's B-36 has always fascinated me . It's one of those weird designs that has one foot squarely in the days of props and another in the jet age. It was both ahead of its time and hopelessly obsolete.
It definitely looks like something from another era. To me it looks like something Jules Verne or H.G. Wells might have imagined.
Expensive, complex and controversial it lasted a mere ten years in service.
Later model B-36 with the addition of jet power.
I actually built a model of this thing years ago, much to my mother's displeasure since it took up so much space in my room. The last I saw it I had left it to my AFROTC detachment at the University of Illinois. For all I know it's still on display there.
The origins of the B-36 go back to the early days of World War II. In 1941 it looked distinctly possible that England might not hold out against the Germans. The Army Air Corps needed an aircraft that could bomb Germany from the United States.
This would have been an awesome aircraft in WWII but it was arguably outdated by the time it saw production.
This required an unheard of range of 10,000 miles. But that's not all. They wanted it to fly at 40,000 feet, above the range of most German anti-aircraft guns. It had to carry a 10,000 pound bomb load, and as long as we're dreaming here let's make it cruise at 300 mph. The original specs were even more ambitious but were scaled back from "impossible with 1940s technology" to just "incredibly difficult".
This was pie-in-the-sky in 1941. To put it in perspective, the B-29 had a combat range of about 3,200 miles and a service ceiling somewhere around 32,000 feet. Mind you the B-29 hadn't even flown yet in 1941.
The prototype lacked the distinctive bubble canopy of the production models.
Still, Consolidated (before they were Convair) thought they could pull it off. They came pretty close. The first B-36 flew in August of 1946. Too late for WWII but still an impressive feat for such a ground-breaking aircraft. No, really, it
broke the ground. Its original landing gear used two gargantuan single main wheels that literally tore up runways. These were quickly replaced by more modern looking 4-wheeled main bogeys, the first use on a production aircraft.
There were only three or four runways in the world that could handle concentrated weight on this single main gear.
The B-36 was a massive aircraft for its time and still quite large even by today's standards. At 230 feet, it's wingspan is longer than that of a 747-8. With a max takeoff weight of 410,000 pounds it dwarfed any existing aircraft. A B-29 was considered a big airplane at the time and it maxed out at a mere 120,000 pounds.
The XB-36 prototype showing the huge main gear.
It was also pretty advanced for the time. The fuselage made extensive use of magnesium to save weight. It was originally powered by six Pratt & Whitney "Wasp Major" 28-cylinder radial engines. These six engines put out a combined 22,800 horsepower! Each engine drove a 19-foot propeller in a "pusher" configuration. This kept the airflow over the wing undisturbed (and more efficient) but caused some problems, which we'll discuss later.
The Flight Engineer's station was directly behind the pilots. The two Engineers (I assume they swapped out) must have kept pretty busy.
Top speed was a leisurely 286 mph (248 knots) indicated, or .66 mach at altitude. Pretty good for a propeller driven aircraft but even in the late 1940s it was obvious that it wasn't going to be good enough.
One of the powerful R-4360 engines. Each one had 28 cylinders and put out a whopping 3,800 horsepower.
In an effort to improve performance, later models had four turbojet engines in addition to the six props. The jets interestingly burned the same aviation gasoline as the piston engines and were used for takeoff or whenever extra performance was needed.
The jet pods with the intake louvers closed. Note the 4-wheeled main gear on the B-36 in the background.
This let to various quips about "six turning and four burning" or "two turning, two burning, two choking, two smoking and two unaccounted for".
Offensive armament consisted of four bomb bays capable of holding up to 86,000 pounds of bombs. That's actually a good bit more than a B-52, except for some of the B-52D's that had the "big belly" modification. Later modifications joined two of the bomb bays together so that it could carry the first generation hydrogen bombs, which were rather huge.
Defensive armament was six remotely controlled gun turrets each with a pair of 20mm cannons. The nose and tail turrets also mounted twin cannons. While impressive sounding, the vibration from firing the cannons played havoc with the vacuum tube electronics. By the mid 1950s all but the tail guns had been removed to save weight.
The gun turrets were normally retracted. Here two of the top turrets are extended. The plexiglass bubble is where one of the gunners would have sat.
The best defense for the B-36 lay in flying higher than most fighters of the day. It could operate well above 40,000 feet and the lightened "featherweight" models easily topped 50,000 feet. At those altitudes the huge wing gave it a decent chance of out turning some of the early jet fighters.
According to my B-36 flight manual, the flight controls were standard cables and pulleys operating servo tabs. The flaps were operated electrically and the landing gear by hydraulics. This has to have been one of the largest aircraft ever to use manual flight controls. I can only imagine a 400 ton aircraft with a 230 foot wingspan and manual flight controls.
B-36 Pilot's station. Looks roomy enough but not sure I'd want to spend 20+ hours there.
One pilot's description was "a horrible, lazy beast to fly". He apparently disliked it so much that he vowed to "join the infantry before he'd fly another one".
It was a terribly complex aircraft, really pushing the limits of piston engine technology. Each of its six engines had 56 spark plugs, all 336 of which required frequent changing because the leaded fuel of the day fouled them. The wings were large enough to allow crew members to work on the engines in flight, although only below 10,000 feet (that area was unpressurized).
Flight manual illustration of the Engineer's station.
It took a crew of 15 to operate the B-36. The reconnaissance models had up to 22. That many people were cramped even in such a large plane. Note that the B-36 wasn't weren't nearly as roomy inside as the movies would lead you to believe. That's pretty common in Hollywood, and probably due to the requirements of shooting a movie.
Forward crew compartment.
The forward and aft pressurized compartments were connected by an 85-foot long tunnel. Moving through the tunnel required lying face-up on a wheeled dolly and pulling oneself along by a rope. This was apparently enough of a chore that it wasn't done all that often.
B-36 missions could best be described as "grueling". A "short" training mission was 14 hours long and 20 hours was common. Some reconnaissance missions, with extra fuel bladders in the aft bomb bay, may have been up to 40 hours long!
Pilot's manual diagram of the forward crew compartment.
The B-36 features prominently in the movie
Strategic Air Command, starring who else but Jimmy Stewart. You'll also recognize Harry Morgan (Dragnet, M*A*S*H) as the flight engineer. The B-36 takeoff roll takes so long you probably have time to get up and make a sandwich.
The B-36 had some flaws. Not surprising in an aircraft that so pushed the edge of the envelope for its day. Keeping the engines cool was a problem. You can see that the engines are very sleekly blended into the wing. This made for low drag but getting sufficient airflow to cool the engines was a problem, especially in the thin air at higher altitudes.
It was not uncommon for one of the piston engines to fail. Here the #3 propeller is feathered. Don't worry. We've got plenty more engines where that came from.
More problematic was carburetor icing. In a normal aircraft, with the propellers in front, the carburetor was placed at the rear of the engine and kept warm by the hot exhaust manifold. On a "pusher" setup like the B-36, the carburetor, by necessity, was at the front of the engine and hard to keep warm. If the carburetor iced up, this restricted the flow of air into it. This made the critical mixture of fuel and air go "rich" or "too much gas not enough air". Excess fuel would get spit out of the engine and collect in the hot exhaust manifold. Engine fires, never a good thing, were all too common. Especially bad on a plane constructed largely of (flammable) magnesium. Three B-36s were lost due to in-flight fires. One of them just happened to be carrying an atomic bomb at the time (oops).
Much controversy surrounded the B-36 program. They were very expensive, both to purchase and to maintain. A B-36 cost roughly $40 million in today's dollars. Even the Air Force was split on whether it was a good idea. Curtis LeMay of course wanted it because it could strike the Soviet Union from bases in the US. Other SAC generals felt that the all-jet B-47 was a better choice, even though it needed to be based overseas to be in striking range of Soviet targets.
An adviser to President Eisenhower once interviewed LeMay about the possibility of a Russian surprise attack on the United States. LeMay was not worried.
"If I see the Russians are massing their planes for an attack, I'm going to knock the shit out of them before they take off."
"But General, that's not national policy!"
"I don't care. It's my policy."
Inter-service rivalries were nothing new but the creation of an independent US Air Force in 1947 spooked the US Navy. The Navy argued that the B-36 could be intercepted by newer jet fighters like their own F2H-2 Banshee and that the money would be better spent on aircraft carriers. The Air Force declined the offer of a match-up between the B-36 and the F2H-2 but in the end we purchased both carriers and strategic bombers. This is the DOD we're talking about here. They're not used to hearing the word "no".
Rare picture of low level fly-by over Manchester England.
It's not well known that a full third of the B-36 fleet were RB-36 reconnaissance models. These had fourteen cameras where the forward bomb bay would have been and even had a dark room to develop the film in flight. The other bomb bays carried ECM equipment, "photo flash" bombs, and extra fuel tanks. The RB-36 had an endurance of up to 50 hours and carried a crew of 22 to operate all the cameras. So it was even more crowded
and they were stuck in there twice as long. Nice.
Photo Navigator's station on an RB-36
The recce version may have been the real reason that LeMay so wanted the B-36. Prior to the development of the U-2, it gave us the ability to overfly Communist airspace without being intercepted. RB-36s definitely overflew Chinese airspace in the 1950s and may very well have overflown the Soviet Union. LeMay was never shy about violating Soviet airspace. He once massed B-47s over Vladivostok. Because he
could.
Curtis LeMay probably warrants his own diary, but JFK summed him up pretty well:
If you have to go, you want Curtis LeMay in the lead airplane, but you don't want Curtis deciding whether or not you have to go.
The B-36 didn't stick around all that long but during its brief service life it spawned a few interesting variations. Some of these must have seemed like a good idea at the time.
The XF-85 looking more than a bit like an egg with wings.
No fighter aircraft of the day had anywhere near the range of the B-36. With air refueling still in its infancy, how then, could they provide it with a fighter escort? The answer was the diminutive XF-85 "Goblin". A tiny jet fighter that the B-36 could carry in one of its bomb bays. The XF-85 pilot certainly would have had incentive to defend the "mother ship" because that was his ticket home! During tests with a B-29, "docking" the XF-85 proved extremely difficult even for a highly experienced test pilot.
In addition, the Goblin never really performed as well as hoped for. The idea was scrapped. It ranks very high on the "awesome" scale, however.
XF-85 docking with a B-29 during testing. This proved to be extremely difficult even for a test pilot.
The idea of using a B-36 as an airborne aircraft-carrier lived on however, with project FICON. A small number of RB-36s were modified to carry an RF-84
Thunderflash reconnaissance fighter semi-recessed under the belly. This was a complicated arrangement. While the B-36 could takeoff and land with the fighter attached, the "trapeze" had to be lowered briefly to allow the bomber's main gear room to retract or extend. More often than not the two aircraft would launch separately and join up in flight.
RF-84 hooking up to the "trapeze". You can tell this is an RB-36 by the extra radomes under the tail.
RF-84 pilot standing in the B-36 bomb bay.
If carrying
one F-84 was good, why not two? Experiments were conducted with an F-84 attached to each wingtip of a B-36. Knowing what we know today about wingtip vortices I'm amazed this was even attempted. A similar experiment using a B-29 as the mother-ship resulted in an F-84 flipping over on its back and killing everyone in both aircraft. The wingtip hookups proved exceedingly difficult and fatiguing for the F-84 pilot. "Project Tom-Tom" was fortunately scrapped before anyone else got killed. I think the lead designer might have been a certain "W. E. Coyote".
Must have seemed like a good idea at the time. F-84 hooked up wingtip to wingtip with a B-36.
Another "seemed like a good idea at the time" experiment was the nuclear-powered NB-36. Well it wasn't really nuclear powered but it did carry a nuclear reactor. There were hopes that it would indeed pave the way for a nuclear powered aircraft with unlimited range. One drawback was the massive shielding required to protect the crew from radiation. The whole idea of having nuclear reactors flying around seems unthinkable today but the Russians also tested something like this.
The NB-36 housed a nuclear reactor in the rear compartment. The cockpit featured lead shielding and extra thick glass on the windows.
Then there was the giant XC-99 cargo plane which was derived from the B-36. To this day the largest land-based piston engine aircraft ever flown. It actually worked quite well but the Air Force didn't see the need for it at the time. An order from Pan Am for an airliner version also fell through. Ultimately only one was built. It hauled cargo for the Air Force up until 1957 when it was parked at Kelly AFB in San Antonio. I can recall seeing it there back in the 1980s.
The XC-99 dwarfed the already huge B-36. It was economical when fully loaded, but there was rarely enough cargo for a full load.
The YB-60 prototype was an attempt to create a fully jet powered version of the B-36.
Basically a B-36 fuselage with a swept wing and tail surfaces, it shared about 72% of its parts with the B-36. It was about 100 mph slower than Boeing's YB-52 prototype and it had handling issues as well. It had an impressive bomb load of 72,000 pounds, however.
The YB-60 was an attempt to build a jet powered B-36.
Could the B-36 have accomplished its mission if called upon to do so? It's hard to say. During the Korean War B-29s fared poorly against Russian-built MiG jets. The B-36, however, flew quite a bit higher than the B-29. Some of the later RB-36s could reach 58,000 feet. Crew members on reconnaissance flights over Manchuria claimed to have seen Chinese MiGs trying, and failing, to reach their altitude.
Rare picture of a B-36 in formation with a B-52 and a B-58. The B-36 served as a stopgap between the days of props and the jet age.
I would guess that it was viable in the early 1950s but by 1955 its days were clearly numbered. The Air Force started retiring them in 1956 and the last ones were parked in 1959. This gave the type a mere 10 years of operational service. For as much as was spent on the B-36 program, we really didn't get a lot of mileage out of it.
Ultimately what Strategic Air Command wanted was a plane that combined the range of the B-36 with the speed of the B-47. The result was, well you know.
B-36 in formation with its replacement, which needs no introduction.
I believe only four or five of these still exist. One sat out at Chanute AFB in Illinois for many years. It has since moved out to the former Castle AFB in California. One is at the Air Force Museum in Dayton and has the XF-85 parked under its wing. One is at the Pima Air & Space Museum in Tucson and one is at the SAC museum in Nebraska.
Finally one is in pieces at some guy's farm in Newbury Ohio. It was at the original USAF Museum but it was cheaper to just fly another B-36 to the new museum than to move the one they had. They scrapped the original display model and sold the pieces. I have no idea what the owner plans to do with it.
If you get a chance to go see one I would highly recommend it. The pictures don't do justice to the sheer size of this thing.