31 March 2011

Operation Teaball: Network-Centric Real-Time Intelligence During Vietnam

In 1972, US fighters had an added resource in the fight against MiGs
In past blog posts I've discussed some of the measures taken by the military to reverse the decline in air combat proficiency in the skies over Vietnam. This past November I had blogged about the origins of Red Flag as well as the top secret USAF program to obtain and fly MiGs. Back in March I wrote about the US Navy's own efforts that began with the Ault Report. While these were all steps that would benefit fighter pilots in the skies over Vietnam, there was another effort that took place that has received scant attention in the history books and presaged today's military buzzword of "network-centric" warfare. Between the bombing halt of 1968 and the start of the North Vietnamese Easter Offensive in 1972, air combat over North Vietnam was nearly non-existent. With the start of the NVA offensive in 1972, though, President Nixon reversed the gradual drawdown of US forces in Southeast Asia with a massive buildup and bombing offensive under Operation Linebacker I and Linebacker II. With the ramp up of offensive air strikes on North Vietnam, US aircrews found themselves embroiled in multiplane dogfights that were resulting in growing US losses. In the three months following the start of Linebacker in May 1972, the US lost 48 aircraft, 21 to VNAF MiGs and 27 to improved ground defenses. In the same period, only 31 MiGs were shot down by US aircraft and things worsened in the summer with 13 US aircraft lost to MiGs and only 11 MiGs shot down. 

At the same time, the policy of rotation of air crews meant that experienced personnel were rotated out of combat and replaced with novice air crews on their first combat tour. In the days before Red Flag and dissimilar air combat training, the loss rate of first tour air crews was staggering enough the General John Vogt, commander of the Seventh Air Force which oversaw combat air operations in Southeast Asia, ordered the minutes of mission critique conferences to be disseminated to all units in theater, not just the units involved. But it wasn't enough for General Vogt. He reported to the USAF Chief of Staff, General John Ryan, that the US was losing the air war over Vietnam in 1972. As a result, General Ryan ordered his staff to create a plan to assist US pilots in the skies over Vietnam- no studies, no plans, but what General Ryan wanted was something in place that could offset the fact that the VNAF MiG pilots were battle-experienced and had excellent GCI controllers who could relay the MiG air crews detailed descriptions of the tactical situation. 

General John Vogt, commander USAF Seventh Air Force
Ryan tasked a three-man "action group" with setting something up- USAF officers Lt. Col. William Kirk and Maj. Ernie Short teamed up with Delmar Lang, an intelligence specialist with the National Security Agency. Lang was brought in as he had several times in the years prior repeated offered to set up an eavesdropping facility that could listen in on the communications between the VNAF MiG pilots and their GCI controllers to provide real time information to US pilots. Lang's idea had historical precedence- during the Korean War, the USAF had a listening post on the island of Cho-do off the coast of Korea that was staffed with linguists and air control specialists that would listen in on North Korean, Chinese, and Russian communications to give US pilots a real-time picture of what was going on in "MiG Alley". Since the Korean War, the pace of technological progress in electronic and signals intelligence (ELINT and SIGINT) improved by leaps and bounds, but national security and a variety of compartmentalized secret programs kept many of these new methods out of sight to those on the front line. Delmar Lang's NSA position, however, coupled with the access given Lt. Col. Kirk and Maj. Short, intended to cut through the institutional resistance to using those technological resources to win the war in the skies of over Vietnam. 

On 26 July 1972, literally in just one month, General Ryan's "action group" set up the Operation Teaball Weapons Control Center at the Thai air base of Nakhon Phanom (nicknamed "Naked Fanny" by US pilots). Working with the intelligence specialists of the USAF's 6908th Security Squadron, the Teaball control room had map displays where data from a variety of intelligence sources already in place was collected and synthesized to form a single tactical picture that could be disseminated to US pilots in real time by specialist ground controllers. Orbiting high over the Gulf of Tonkin and Laos, specialist ELINT/SIGINT RC-135s listened in on communications between MiG pilots and their GCI controllers- this data was then relayed to a Lockheed U-2 orbiting high overhead that then relayed the information direct to the Teaball control center at Nakhon Phanom. Ground and ship-based (like "Red Crown" in the Gulf of Tonkin) radar pictures were added to refine the tactical picture. Finally, radar and SIGINT data from specialist EC-121s- such as the famous radar early warning EC-121 that used the call sign "Disco"- was also relayed to the Teaball specialists as well. Also little known was a US capability to trigger the IFF systems of the MiGs so they could be easily tracked. The stream of data from all these sources made use of a top-secret NSA computer system called "Ironhorse" that was designed to analyze and synthesize all the data to create a cohesive tactical picture that was then displayed on the map screens for the Teaball controllers to relay via another radio relay RC-135 to US pilots over North Vietnam. Once the system was up and running, the delay was as little as 45 to 60 seconds before the Teaball controllers were issuing advisories to US pilots!

"Combat Lightning" was one many specialist KC-135 variants used
Each combat air crew, regardless of service branch, were notified of a discrete UHF channel to monitor that advisories from the Teaball control center were broadcast. Teaball controllers also knew the call signs of each and every combat mission for that day going into North Vietnam. Positions of VNAF MiGs were given in relation to a notional point called the "Bull's Eye" which was Hanoi. Distance and bearing from the Bull's Eye was given and air crews often programmed the Bull's Eye into their aircraft's own navigational equipment. "Blue Bandits" were MiG-21s, "White Bandits" were MiG-19s, and "Red Bandits" were MiG-17s. The code word "Green Bandit" indicated an exceptionally experienced VNAF MiG pilot was airborne. "Heads up" meant MiGs were nearby. Teaball controllers and analysts noted that certain combat flights were targeted especially heavily by the MiGs at times, and these US air crews were designated "Queen for a Day". A Teaball controller might inform a flight of F-4s about "Red Bandits, 25 miles SE of Bull's Eye, heading NE 300 knots" over a designated UHF channel. In effect, the Teaball controller acted as a GCI controller for the US pilots, constantly feeding them information on the position and action of any MiGs nearby to allow the US pilots to exploit the situation.

Lt. Col. Kirk briefed every unit that was flying combat missions over Vietnam and warned them explicitly "Pay attention when I call you on that channel!" Within the first month of Operation Teaball's operation, American fighters had moved from a 1:1 kill ratio to a 3:1 ratio and by the end of the Linebacker operations, the ratio had risen to 4:1 in favor of US air crews. The system saved many an air crew's life in the skies over North Vietnam, to the point that inbound flights often checked in with the Teaball control center once they had taken off to be sure they had their call signs!

Operation Teaball was one of the earliest and most successful uses of data fusion and what today we would call "network-centric" warfare- to use diverse data collection sources fused together to give situational awareness to our men and women in combat. It was the first time that such diverse sources of intelligence that were once the sole realm of distant analysts in the United States were used to deliver real-time actionable information to win battles. 

Sources: The Linebacker Raids: The Bombing of North Vietnam, 1972 by John T. Smith. Arms and Armour, 1998, p95-97. Air Force Magazine, July 2008, Volume 91, Number 7. "The Teaball Tactic" by Walter Boyne.

17 March 2011

The Bell 207 Sioux Scout- Grand Daddy of the Gunship

The Bell D-245 Warrior set the pattern for gunship designs
With the turbine-powered Bell UH-1 Iroquois "Huey" utility helicopter offering a quantum leap in capability for the US Army over previous, cumbersome, piston-driven rotorcraft, it was a natural progression that the UH-1s would be armed for aerial fires support for the growing conflict in Vietnam. But Bell's engineers in Fort Worth were steps ahead of the military with studies as early as 1958 for a tandem-seat purpose-built helicopter gunship that used the transmission and engine systems of what would become the UH-1. Bell's first offering had the in-house designation D-245 and was named "Warrior" which laid down the standard layout of gunships that followed- a slim fuselage with tandem seating for a pilot and gunner, stub wings for weapons, and nose-mounted gun turret. But despite its potential, the Army had yet to determine operational doctrines for the use of attack helicopters and the D-245 Warrior was quietly shelved. 

Despite official disinterest from the US Army, Bell decided to embark on internally-funded development to further refine the D-245 Warrior design. In June 1962 Bell unveiled the D-255 Iroquois Warrior to the Army at its Fort Worth facility. The D-255 was a bit larger than the earlier D-245 but retained the tandem seating for pilot and gunner in stepped layout with the pilot sitting behind and higher than the gunner in the forward seat. Again, the tail boom, rotor transmission and engines were adapted from the UH-1. While the mixed reaction from the US Army was an improvement over the official disinterest that the earlier D-245 design elicited, it still wasn't enough to get a production contract from the Army. Again the D-255 was quietly shelved, but this still wasn't going to discourage the Bell team from staying ahead of the game. In December 1962 a brainstorming session of the engineering team resulted in a decision to build a flying demonstrator to prove the US Army what Bell's gunship concept could accomplish. 

The Sioux Scout was quite small for a two-seat gunship
Designated the Model 207 and named the Sioux Scout, the demonstrator combined the engine, rotor, and drive systems of the proven Bell OH-13 Sioux (the bubble-cockpit helicopter made famous in the introduction to the TV series M*A*S*H) with its civilian counterpart, the Bell 47. The six-cylinder Lycoming 435 engine of the OH-13/Bell 47 was supercharged to deliver 220 horsepower driving the main rotor system from the OH-13 and the tail rotor/tail boom of the Bell 47. An all-new slim fuselage was created that used box beams to create a rigid structure to which were attached the stub wings that could carry external stores on six hardpoints on each side as well as house an additional 43 gallons of fuel which gave the Sioux Scout a range of 200 miles. At high speeds, the stub wings helped offload the main rotor as well. An Emerson Electric TAT-101 gun turret was installed under the nose (the rigid fuselage structure dampened recoil) housing twin 7.62mm machine guns that were adaptations of the M60 gun. With 1,100 rounds of ammunition, the gunner in the forward seat used a pioneering hand controller to operate the gun turret 100 degrees side to side, 15 degress upward, and 45 degrees downward. Under each stub wing were six round, 2.75 inch rocket launchers on each hardpoint. 

The gunner had an outstanding field of view from the front seat
The Sioux Scout made its first flight from Bell's Fort Worth facility in Hurst on 27 June 1963, in the process becoming the first pure gunship in the world to take flight. Since the demonstrator program was somewhat secret, the helicopter was painted red and white to not so blatantly give away its military purpose. After several weeks of testing with Bell that added up to 65 flight hours, the Sioux Scout was repainted in more Army-like olive drab and began a series of weapons tests at Fort Sill, Oklahoma, northwest of Fort Worth. In November of that year, the Sioux Scout was taken on the road, touring Army bases and being flown by both Army and even NASA test pilots with over 300 flight hours that included firing over 83,000 rounds of ammunition from the chin turret. Finally, in 1964, B Troop, 3rd Squadron, 17th Cavalry of the 11th Air Assault Division spent a month flying the Sioux Scout in operational conditions and in field exercises. At the time, the 11th Air Assault Division was tasked by the Army commanders with experimenting and creating operational doctrines in helicopter assault at Fort Benning, Georgia. 

The Model 209 prototype had retractable landing skids
Other than the Sioux Scout being underpowered and the reliability of the experimental gun turret being less than ideal, Army evaluators were overwhelmingly pleased with the outcome of the 11th Air Assault Division's operational evaluation of the demonstrator. The recommendation was issued that a turbine-powered, more capable version be developed as quickly as possible for operational use. In late 1964 the Secretary of the Army created the Advanced Aerial Fire Support System (AAFSS) with invitations to industry to submit designs. With the quick realization that the AAFSS design would take time to field, the Army decided that an interim design was needed that would field the gap until the AAFSS became operational. Bell dusted off its D-255 Iroquois Warrior design and with further refinements based on the Sioux Scout evaluation, designated it the D-262. However, in 1965 the Army rejected the D-262 design. But, as Bell had done before, they quietly went about refining the design further on company funds- within several months of the rejection of the D-262, the situation in Vietnam worsened and the US commander in Vietnam, General William Westmoreland, advised the Pentagon that either the AAFSS needed to fielded quickly or some interim design was needed as soon as possible. In March 1965 Bell just happened to finish the full-scale mockup of its refined gunship designated the Model 209 and "leaked" to Army commanders what it was up to. Before long, the Army issued a formal requirement for an interim design. Beating out submissions from Sikorsky, Kaman, Piasecki and Boeing Vertol, the Model 209 was selected on 11 March 1966 for production as the AH-1 Cobra.

And the AAFSS? That became the Lockheed AH-56 Cheyenne and was a classic case of wanting too much out of a design. It ended up getting cancelled in August 1972. That same month, the Army created the Advanced Attack Helicopter program (AAH) which became the AH-64 Apache. And what become of the Sioux Scout? The grand daddy of gunships can be seen today in the Army Aviation Museum in Fort Rucker, Alabama. And of course, Bell's interim design is still in production today for the US Marine Corps as the AH-1Z Viper.

Source: Helicopter Gunships: Deadly Combat Weapon Systems by Wayne Mutza. Specialty Press, 2010, p56-60. Images from aviatstar.org

12 March 2011

The "Wings of Russia" Sukhoi Super Jumbo

The Sukhoi KR-860 was conventional in its layout
At the 2001 Paris Air Show, the Russian delegation created quite a stir by unveiling a four-engine, double-deck, long-haul airliner christened "Kryl'ya Rossii", or "Wings of Russia". The ambitious project had the Sukhoi OKB designation "KR-860"- KR for "Kryl'ya Rossii" and 860 indicating the passenger load. Design work on the KR-860 began in 1997 under the General Designer, Mikhail P. Simonov who had headed the design bureau since 1983. Already under his direction the Su-27 Flanker family of fighter aircraft had been upgraded and new variants had taken flight. By the time that design work began on the KR-860 project, Sukhoi had already been making its first steps into the civil aviation market with the start of work on the Su-80 utility transport and the Su-38 agricultural aircraft. But an aircraft in the class of the KR-860 was nothing short of a bold leap by Sukhoi. The "Wings of Russia" would rival the Airbus A380 and would be larger than the Boeing 747. The design team had looked at advanced technologies and unconventional layouts such as a flying wing, but eventually settled on a blend of advanced technologies (fly-by-wire, composites) combined with a conventional layout with a double deck fuselage and four turbofans. At each step of the KR-860's design evolution, tradeoffs were made between high technology and innovation and low-risk approaches. 

Note the twin nose gear and unusual cockpit fairing
Although the layout of the KR-860 was conventional in appearance, the Sukhoi team succeeded in achieving a predicted lift/drag ratio of 19.5 (compared to the L/D ratio of the Boeing 747 of 17) via aerodynamic refinements. Large winglets were a part of the design and the smooth lines of the double deck fuselage were unusually broken by a blister-like fairing that housed the flight deck. One of the more unusual features of the KR-860 was its use of folding outer wings to reduced the footprint of the aircraft. Boeing had looked at a similar system during the design of the Boeing 777 and had even built a test article, but eventually dropped the idea as the gain in space at the gate wasn't enough to offset the increased weight and complexity. For the KR-860, though, the folding outer wings meant that the aircraft could use any gate position that could accommodate a Boeing 747. While the main landing gear was very similar to that of the 747 and A380 with two inward-retracting wing units and two fuselage mounted units, the nose landing gear was more like that of the Antonov An-124 Condor transport with twin units. The third unique feature of the KR-860 was its three integral airstairs that were on the centerline of the underfuselage- the forward airstair was ahead of the nose gears, the second one was mid-way down the fuselage where the wings were located, and the third and aft unit was under the tail. Like the integral airstairs on the Ilyushin Il-86, these were meant to reduce the ground support needs for the KR-860. 

Note the folding outer wings and the boarding airstairs under the nose
A variety of powerplant options were evaluated for the aircraft- the most serious contender was the General Electric CF6-80E1 used on the Airbus A330 family of aircraft- Sukhoi was reportedly in negotiations with GE at the time of the KR-860's unveiling at the 2001 Paris Air Show. License production of the engine in Russia was even discussed. In addition, consideration was also given to the Rolls-Royce Trent 800 used on the Boeing 777 and the Pratt & Whitney PW4168 used on the A330. In addition, Russian solutions were evaluated from the Kuznetsov NK-93 ducted fan to the unusual suggestion of using eight Soloviev PS-90 turbofan engines in paired nacelles. This would have been the cheapest solution, but the pair nacelles and eight engines would have been significantly heavier and cost more in fuel consumption. 

The aft boarding airstairs under the tail
The eight-engined variant was considered more appropriate for a cargo variant which had an upward-hinged nose visor like that of the An-124 Condor and the Boeing 747-400F. Sukhoi even pitched this version as a successor to the An-124s operated by the Russian Air Force. The cargo version was capable of carrying up to thirty of the 40-foot rail/road cargo containers. Using four turbofan engines, such a version was claimed to have a cost per mile only slightly higher than that of rail transit. In addition, combi versions were suggested and one of the more unusual variants was that of a flying liquified natural gas (LNG) tanker to connect outlying regions in Siberia planned for oil/gas exploration that lacked suitable infrastructure for conventional transport methods. 

Sukhoi estimated the costs for the development of the KR-860 would be more than offset with its use in cargo transport. Costs depending upon the authority consulted ranged from 3-4 billion US dollars to as high as 5.5 billion US dollars. As ambitious as the KR-860 was, there was simply not enough passenger traffic in Russia to justify an aircraft its size. Sukhoi turned to both India and China which had booming passenger markets to explore risk-sharing partnerships. At the end of the day, though, an aerospace project the size and scope of the KR-860 was simply more than both Sukhoi and the Russian government could handle and with more pressing financial needs, the Kremlin was reluctant to invest in the development of Sukhoi's super jumbo. Russian aviation authorities were highly skeptical of the need for the KR-860 given that most of what might get built would be exported to more robust and booming aviation markets. As a result, the KR-860 "Wings of Russia" program died quietly as Sukhoi shifted its resources to a much smaller aircraft that was needed in Russia to replace the aging fleets of Tupolev Tu-134 and Tu-154 fleets. Though development of the Sukhoi SuperJet 100 had started in 1999, the shift of OKB resources from the KR-860 to the SuperJet program which was formally launched in 2002. 

Source: OKB Sukhoi: A History of the Design Bureau and its Aircraft by Yefim Gordon and Dmitriy Komissarov. Midland Publishing, 2010, p501-503.