The Boeing B-47 In Service

The B-47 was the first line of America's strategic defense in the late 1950s and early 1960s, standing guard with nuclear weapons against the Soviet Union. Its nuclear strike role was highly visible, but while bomber variants of the B-47 never fired a shot in anger, the reconnaissance versions played a dangerous and secret game of probing Soviet airspace, occasionally taking fire and suffering losses. These secret B-47 spy missions remained classified for decades.

The B-47 was also modified for a wide range of special roles, particularly late in its career when it was being phased out of first line service. This chapter surveys the B-47's operational career, and its special variants and modifications.

The Boeing B-47 in SAC service

When B-47s began to be delivered to the Air Force, most crews were excited about getting their hands on the hot new bomber. The thing was so fast that in the early days the B-47 set records everywhere it flew without even trying. The aircraft handled well and comfortably in flight, with a fighter-like light touch to the controls. The big bubble canopy also enhanced the fighter-like feel of the big aircraft, though it could make the cockpit a "hotbox" on sunny days, while the navigator in the nose froze.

However, it took the Air Force until 1953 to turn the B-47 into an operational aircraft. The big aircraft was sluggish on takeoff and too fast on landings -- a very unpleasant combination of flight characteristics. Furthermore, if the pilot put the machine down at the wrong angle on the bicycle landing gear, the aircraft would "porpoise", bouncing fore-and-aft. If he didn't lift off for another go-round, the instability would quickly cause the bomber to skid onto one wing and cartwheel to its destruction.

Improved training led to a good safety record and few crews felt the aircraft was inherently unsafe or too demanding, but apparently there were aircrews who had little affection for or were even afraid of the B-47. Crew workload was also high, with only three crew members to keep the B-47 flying right. The B-52, in contrast, generally had six crewmembers, with roomier accommodations.

The B-47's reliability and serviceability were also regarded as good in general, the exception being the electronic systems, but that was true for all aircraft with complicated electronic systems in that era: something was always broken. Much work was done to improve the reliability of the electronics systems, but they remained something of a maintenance headache all through the B-47's operational life.

By 1956 the US Air Force had 28 wings consisting of a total 1,306 B-47 bombers and five wings consisting of a total of 254 RB-47 reconnaissance aircraft, for a sum of 1,560 machines. This was the peak strength of the Stratojet, though the number of bombers would increase into 1958 to 1,367, while the number of reconnaissance machines decreased to 176. The B-47s were armed with Mk 28, Mk 36, Mk 42, Mk 53, and B43 free-fall nuclear weapons. Stratojets were given a coat of white paint on the bottom to help reflect the flash of a nuclear explosion, though the top of the aircraft remained in natural metal finish.

The bombers were the first line of America's strategic nuclear deterrent, many operating at forward bases in the UK, Morocco, Spain, Alaska, and Guam. Overseas deployments of entire wings began in 1953 and involved 90-day rotations. B-47 bombers were often set up on "one-third" alert, with a third of the operational aircraft available sitting on the runway, loaded with fuel and nuclear weapons, crews on standby, ready to take off on an all-out attack against the USSR at short notice.

Crews were also trained to perform "minimum interval take-offs (MITO)", with one bomber following the other into the air at intervals of as little as 15 seconds, to get all the bombers on the way as fast as possible. MITO could be very hazardous since the bombers left turbulence and, with water-methanol injection, dense black smoke that blinded pilots in the following aircraft.

In 1956, when the Stratojet force was at its peak, SAC conducted two exercises, OPERATION POWER HOUSE and OPERATION ROAD BLOCK that put more than 1,000 B-47s and KC-97s into the air to intimidate the USSR. Apparently B-47 bombers even performed training missions in which they penetrated Soviet airspace in numbers. The facts behind these missions remain controversial, with some sources claiming that SAC commander General Curtiss LeMay ordered them without presidential knowledge or approval.

In the late 1950s, operational practice for B-47 bomber operations went from high altitude bombing to low altitude strike, which was judged more likely to penetrate Soviet defenses. Bomber crews were trained in "pop-up" attacks, coming in at low level and then climbing abruptly on nearing the target before releasing a nuclear weapon, and the similar "toss bombing" procedure, in which the aircraft released the weapon while climbing and then rolled away to depart the target area before the bomb fell back down and detonated.

It was a spectacular maneuver and a thrill to watch. Unfortunately, stresses due to low altitude operations led to a number of crashes, and an extensive refit program was initiated in 1958 to strengthen the wing mountings. The program was known as "Milk Bottle", named after the big connecting pins in the wing roots that had to be replaced.

The B-47 would be the backbone of SAC into 1959, when the B-52 began to take over and the B-47 wings started to be cut back. Actual B-47 production had ceased in 1957, though modifications and rebuilds continued after that. Final phaseout of B-47 bomber wings began in 1963, and the last bombers were out of service by 1965.

The Boeing RB-47’s and the cold war

The only B-47s to see anything that resembled combat were the reconnaissance variants. They operated from almost every airfield that gave them access to the USSR, and they often probed Soviet airspace. Sometimes they stirred up more trouble than they could handle. The stories were kept secret for a long time, with the families of aircrew killed simply told that there had been an unspecified accident. The facts only started to come out in earnest in the 1990s.

The first overflight of Soviet territory with an RB-47 took place on 15 October 1952, when an RB-47B -- a standard B-47B that had been converted to a daylight reconnaissance configuration on a fast-track basis -- flying out of Alaska overflew Soviet airfields in Eastern Siberia. The Soviets scrambled MiG-15s to intercept, but the fast RB-47B got away unharmed. The Soviets apparently sacked the local commander of air defenses in the region.

On 8 May 1954, an RB-47E flying out of RAF Fairford was paralleling the Soviet border over Norwegian airspace, and then abruptly turned into Soviet airspace to overfly airfields around Murmansk. The RB-47E was flying at high altitude, out of reach of MiG-15s, but unknown to USAF intelligence some MiG-17s had been stationed in the area and they were able to intercept the intruder. The RB-47E's tail turret malfunctioned, as it often did, and the crew couldn't shoot back, while the big aircraft took some hits and was damaged. It managed to get back out of Soviet airspace over Finland and finally performed an emergency landing at RAF Brize Norton after a last-minute cliff-hanger topping off from a KC-97. Finnish news reports indicated an air battle, but the USAF denied that any US aircraft had been in the area.

The pilot, Hal Austin, was reprimanded by the commander at Brize Norton for defying control-tower instructions. Back on the runway, the aircraft's crew chief looked over one of the cannon holes in the fuselage and asked the pilot: "What the hell did you hit?" The whole thing was completely secret and so Austin only replied: "It wasn't a seagull." The reprimand was quietly removed from Austin's record under LeMay's orders, and Austin was even more quietly awarded a medal for the risky mission.

One RB-47 flying out of Alaska was scouting out the Kamchatka Peninsula on 17 April 1955, when it was bounced by Soviet MiG-15s in international airspace. The RB-47 and its crew disappeared. They were probably lost in the shoot-down, but there is a remote possibility that some or all were captured, run through the mill by Soviet interrogators, and then shot in the head.

The loss did not deter the USAF. Between 21 March and 10 May 1956, 16 RB-47Es and 5 RB-47Hs operating from Thule, Greenland, performed overflights the length of Siberia 156 times under PROJECT HOME RUN, with six RB-47Es flying in during the final flight of the series. The Soviets never got a clear shot at the intruders. They filed an angry complaint with the US government, which blandly attributed the overflights to "navigational difficulties".

MiGs did bounce RB-47s on three separate occasions in the fall of 1958, with one incident over the Black Sea on 31 October, the second over the Baltic on 7 November, and the third over the Sea of Japan on 17 November. In all three cases, the RB-47s got away without serious injury.

In one of the few incidents that made headlines, an RB-47H flying out of RAF Brize Norton was jumped and shot down over the Barents Sea on 1 July 1960. The Soviets claimed it had violated their airspace, while the Americans insisted that it was well out over international waters and, of course, not on a surveillance mission. It appears that it actually was well out in international airspace, but the Soviets were annoyed over recent overflights. They wanted to send the Americans a message that such provocations would have consequences, and that hiding behind the rules wasn't going to be any protection.

The aircraft's pilot was Major Willard G. "Bill" Palm, his copilot was Captain Freeman "Bruce" Olmstead, and his navigator was Captain John R. McKone. Olmstead and McKone managed to eject safely and were captured. Palm and the three crew in the bombbay reconnaissance pod -- Major Eugene Posa, Captain Oscar Goforth, and Captain Dean Phillips -- were all killed. Palm's body was recovered and sent back to the US. Olmstead and McKone were convicted as spies and loudly played up as propaganda pawns, but both were swapped back to the US on 25 January 1961 after they had basically outlived their usefulness.

The last known confrontation between MiGs and RB-47s took place on 27 April 1965, when an ERB-47H was jumped by North Korean MiG-17s over the Sea of Japan. The MiGs gave the ERB-47H a working over, but it managed to make it back to Yokota Air Base in Japan with two engines out.

Unusual B-47 variants and modifications

Aside from production aircraft, there were quite a number of conversions and oddball special modifications in the B-47 line. B-47B conversions and special modifications included:

The Air Force had considered building a specialized "RB-47B" reconnaissance variant to complement the B-47B bomber version, but as it turned out schedule slips and the like ensured that the RB-47E was the first production reconnaissance variant. As as interim measure before the RB-47E went into service, 24 B-47B bombers were fitted with a heated pod with eight cameras that was stowed in the forward bombbay, and these aircraft were designated RB-47Bs. They were capable of daylight reconnaissance only, and as mentioned earlier, were the first RB-47s to overfly Soviet airspace.

A total of 66 B-47Bs were also converted into "TB-47B" trainers, through the simple measures of adding a fourth seat for an instructor and removing the tail turret. These aircraft provided valuable crew training for the demanding B-47 through most of the 1950s.

With the introduction of the hydrogen bomb, the USAF contemplated the conversion of a few B-47Bs into "MB-47B" drones, which would essentially be huge cruise missiles carrying H-bombs. The program was known as "Brass Ring". Closer examination of the scheme showed that it was impractical, and Brass Ring was cancelled on the appropriate date of 1 April 1953.

There were various flight tests through the 1950s for using the B-47B as a launcher for the big (9.5 meter / 31 foot) liquid-fueled "GAM-63 Rascal" missile, and one B-47B was modified to become a "YDB-47B" Rascal launcher. However, the Rascal program was politically and technically "snakebitten", and never became operational, though a total of 74 B-47Bs were modified into "DB-47B" Rascal launchers before the program got the axe.

In 1956, a single B-47B was obtained by the Airways "amp; Air Communication Service (AACS), part of the Military Air Transport Service (MATS), making it one of the handful of B-47s that wasn't operated by SAC. MATS was on the way towards acquiring jet transports that could fly higher and faster, and so the AACS used their B-47B, nicknamed "Sweet Marie", to perform high speed and high altitude checks of aircraft navigation networks, landing systems, and control tower procedures. This B-47B featured a colorful paint scheme, with orange-red lightning bolts on a white overall finish. It was returned to bomber duty in 1962.

MATS would go on to acquire more B-47s. In November 1957, the Air Weather Service of MATS also obtained a single B-47B, which was converted into a "WB-47B" weather reconnaissance aircraft and also sported a snazzy orange-red-on-white color scheme. It was originally used as a "hurricane hunter", and then used in the early 1960s to take high-altitude pictures of cloud cover to provide calibration checks for the new Tiros series of weather satellites. It was retired in 1963 and used as a ground instructional airframe.

In 1953, two B-47Bs were modified for testing the probe-and-drogue refueling system. The tanker was given the designation "KB-47G" and was known as "Maw" by flightcrews, and was fitted with a British-built tanker kit. The refueling test aircraft was given the designation "YB-47F" and was known as "Paw", though other aircraft were also used as refueling targets.

The program was cancelled in 1954, since it turned out the KB-47G simply could not carry enough fuel to make it a useful tanker. The idea of fielding B-47 tanker conversions came up again a few years later, but the economics didn't make sense, and the notion was finally put to rest for good in 1957.

One of the oddest B-47B conversions was the "CL-52", which was a B-47B loaned in 1956 to the Royal Canadian Air Force to test the big Orenda Iroquois turbojet for the Avro Canada CF-105 Arrow interceptor. Canadair attached the Iroquois engine to the right side of the rear fuselage near the tail, of all places, simply because there was no other place to put it.

Flying the CL-52 was reportedly a nightmare. After about 35 hours of engine flight tests, the Arrow project was cancelled in early 1959, and the B-47B / CL-52 was returned to the US. Some sources claimed it was bent out of shape by the tests, but in any case it was then scrapped. The CL-52 was the only B-47, or for that matter the only US heavy strategic jet bomber, to ever be used by any foreign service. However, in 1963, the USAF did demonstrate three B-47Es to Australian crews, as a possible stopgap before Australia acquired the FB-111. Nothing came of this exercise.

The "YB-47C" (originally the "YB-56") was proposed by Boeing in 1950. It was to be a major variant, with four big Allison J71-A-5 turbojet engines, providing 44.88 kN (4,575 kgp / 10,090 lbf) thrust each, in place of the six GEs J47s.

A B-47B was set aside to be converted to the prototype. The J71 engine program suffered setbacks, and so the Air Force decided to use the Pratt & Whitney J57 turbojet instead. However, the USAF then had second thoughts about the entire program, since by that time the future was clearly the B-52 and the B-47 was essentially an interim type, and gave up on the idea in December 1952.

Beginning in 1951, two "XB-47Ds" were modified from B-47Bs as purely experimental platforms, with a big Wright YT49-W-1 turboprop engine spinning a huge four-paddle prop, replacing each of the inboard two-jet pods. Difficulties with engine development delayed first flight of the XB-47D until 26 August 1955. The aircraft's performance was comparable to that of a conventional B-47, and its reversible propellers shortened the landing roll, but the USAF did not follow up the idea. One might suspect the thing was really noisy.

Boeing B-47E conversions and special modifications

In 1955, a number of B-47E-Is were fitted with external pods, one mounted on either side of the bombbay, with each pod containing four AN/ALT-6B jammers. The pods were known as "Tee Town pods" and so these aircraft were known as "Tee Town B-47s". They retained their normal bombing capability.

The Tee Town B-47s then led to a specialized ECM conversion of the B-47E, which was given the designation "EB-47E". The initial EB-47 conversion featured a set of 16 jammers in a removable cradle stored in the bombbay, plus radar warning receivers and chaff dispensers. These were known as "Phase IV" or "Blue Cradle" EB-47Es.

The more advanced "Phase V" EB-47E featured a pressurized module that was stowed in the bombbay, with 13 jammers under control of two crows. While the Phase IV jammer system was "broadband", blanketing a wide range of frequencies in hopes of jamming radars operating somewhere within that range, the Phase V jammer system could be selectively tuned to specific radar frequencies by the crows, permitting much higher jammer power on the frequencies that did the most good.

A radar jammer tends to announce its presence and location by the radio signals it emits, and EB-47E crews were perfectly aware that they were unlikely to return from an operational mission into the USSR. If they could cover for B-47 bombers, however, the sacrifice would be worth it. About 40 B-47Es were converted to B-47Es. Of course they couldn't carry bombs, but they did retain the tail turret.

Two more B-47Es were converted to EB-47Es in the mid-1960s for US Navy service, on indefinite loan from the USAF. They were very much unlike the USAF EB-47Es, with some of their ECM gear fitted into pods carried on the external fuel tank pylons. They were used for tests of naval ECM systems and as "electronic aggressors" in naval exercises. These two aircraft were the last B-47s in service, and one performed the very last operational flight of a B-47 on 20 December 1977.

Three B-47Es were converted to the highly specialized "EB-47E(TT)" configuration to be used for "telemetry intelligence", picking up radio signals from Soviet missile tests and space launches. The EB-47E(TT)s featured a "crow capsule" in the bombbay loaded with the appropriate gear and two crows, and also featured odd and distinctive "armrest" antennas just below each side of the cockpit.

All three of these aircraft were operated out of Turkey, and stayed in service until 1967. The armrest antennas attracted a good deal of attention from nosy personnel, and crews made up imaginative stories about them, for example claiming they were part of a "return to fighter (RTF)" defensive system that would cause Soviet air-to-air missiles to loop back and shoot down their own launch aircraft.

As with the B-47B, a few B-47Es were converted to trainers, with a fourth seat for an instructor, and given the designation "ETB-47E". These aircraft were used to replace TB-47Bs that had got too long in the tooth, and served into the early 1960s.

Similarly, two B-47Es were converted to "YDB-47Es" to support the Rascal stand-off missile program, and two more B-47Es were converted to "DB-47Es" in preparation for the operational introduction of the missile before the program was killed. These two DB-47Es were later used as drone controller aircraft.

Following the single WB-47B weather reconnaissance conversion, in 1963 34 B-47Es were converted by Lockheed into "WB-47Es" for weather reconnaissance, and operated by the Air Weather Service of MATS. These aircraft were stripped of combat gear, including the tail turret. They were fitted with cameras in the nose to take pictures of cloud formations, and carried a special meteorological instrument pod in the bombbay. The last WB-47E was retired on 31 October 1969, and was the last B-47 in operational USAF service.

In 1963, the Air Force modified 35 B-47Es to carry a communications relay system. These aircraft were given the new designation of "EB-47L", and were used to support US flying command post aircraft in case of a nuclear attack on the US. The EB-47Ls only remained in service for a few years, since improved communications technologies quickly made them redundant.

A total of 14 B-47Es were converted to "QB-47E" target drones in 1959 and 1960. These aircraft were radio-controlled, and included such interesting features as self-destruct charges and arresting gear to assist in landings. They also carried pods mounted on the external tank pylons to help in scoring weapons tests. Apparently most of the missiles fired on them were directed for a near-miss, but the QB-47Es were still eventually whittled down to two survivors that were retired in the early 1970s.

A single B-47E was modified to test the MA-2 BNS for the B-52, and given the designation "YB-47J". Other B-47Es were also apparently used in the MA-2 tests, but not given a special designation.

Several B-47Es were assigned to other specialized test duties and given the blanket designation of "JB-47E". One was used in the late 1960s to test "fly by wire" control system concepts.

Two B-47Es were also used for secret flight experiments in the early 1960s and given the designation "JTB-47E", and a third, even more mysterious modified B-47E was given the designation "JRB-47E". They seem to have been test platforms for ECM systems.

The final RB-47H to be retired from service was later pulled out of the "boneyard" and used for tests of avionics for the General Dynamics F/B-111. This RB-47H was fitted with an F-111-style nose and flew into the early 1970s. It was not given any special designation.

Finally, a B-47E was loaned to the US Navy to help test the GE TF-34-2 turbofan for the Lockheed S-3 Viking carrier-based antisubmarine warfare aircraft. This B-47E was given the designation "NB-47E" and performed test flights from 1969 through 1975.

The final recorded flight of a B-47 was on 17 June 1986, when a B-47E was flown from the Naval Weapons Center at China Lake, California, to Castle AFB, California, to be put in the air museum there. There are at least 15 B-47s that survive on static display, including a spectacular exhibit at the USAF Museum in Dayton, Ohio, but none are still flying.

Boeing B-47 bomber total build quantities

The B-47 was undeniably successful on its own terms. Just as importantly, it led directly to the Boeing B-52 , which still survives as an important US military asset, and provided much inspiration for the design of Boeing's KC-135, which survives prominently in Air Force service to this day, and the Boeing 707, the basis for the modern commercial jetliner.

The B-47 still looks pleasing today, but considering what most of its contemporaries looked like, it must have appeared revolutionary when it was introduced. The white antiflash paint scheme helped give the aircraft a clean, elegant appearance.

Author: Greg Goebel