The Sky is No Longer the Limit Celebrating 75 Years of Air Force Technology
The National Security Act of 1947 became law on July 26, 1947, creating the United States Air Force. On September 18, 1947, W. Stuart Symington became the first Secretary of the Air Force. Since its inception, the mission of the United States Air Force has been to fly, fight, and win — delivering airpower anytime, anywhere in defense of our nation. On September 18, 2022, the Air Force will celebrate its 75th anniversary, continuing this mission.
The early years of the new independent Air Force brought technological breakthroughs, resulting in new capabilities and even new missions. From the earliest days of flight, airmen strived to set or exceed new altitude, speed, and distance records. The early years of the Air Force brought new technologies that resulted in exponential improvements in these and other areas.
In October 1951, the Air Force Office of Scientific Research (AFOSR) was created to manage basic research for the Air Force. AFOSR partners with government agencies, the academic research community, and industry, investing in long-term, broad-based research in aerospace-related science and engineering and exploits revolutionary scientific breakthroughs to address the needs of the Air Force. As part of the Air Force Research Laboratory (AFRL) — which was officially launched in 1997 — AFOSR does not conduct its own research and has no research facilities. Rather, AFOSR’s scientists and engineers closely watch developments in their respective disciplines to identify far-term technologies for the Air Force of the future.
An Early Milestone
One of the most famous barriers broken by the new Air Force was the sound barrier. That breakthrough established the importance of significantly higher velocities than had been achieved previously, ensuring that airframes and humans could operate effectively at high speeds. On October 14, 1947, Capt. Charles E. “Chuck” Yeager broke the sound barrier at Muroc Air Base, CA in a rocket-powered Air Force research plane – the Bell XS–1.
On December 10, 1954, in a rocket-propelled sled run, Col. John P. Stapp attained a speed of 632 miles per hour and sustained greater G forces than humans had ever endured in recorded deceleration tests — the equivalent of Mach 1.7 at 35,000 feet. The test determined that humans could survive ejection from aircraft at supersonic speeds. Then, on February 26, 1955, test pilot George Smith ejected from an F-100 Super Sabre traveling at Mach 1.05, becoming the first person to survive ejection from an aircraft flying at supersonic speed.
Laser research was a field addressed early on by the Air Force when it partially supported the research of Dr. Charles Townes, J. P. Gordon, and H. J. Zeiger at Columbia University in 1953. The research led to the development of the Microwave Amplification by Stimulated Emission of Radiation (MASER) in 1954. A laser is a MASER that works with higher frequency photons in the ultraviolet or visible light spectrum. The result was the first amplifier using energy changes in the electrons of a gas to amplify signals in the microwave region. Dr. Townes’ effort led to an explosion of laser-related breakthroughs by numerous researchers who were supported by the Air Force.
The first time lasers accompanied US military forces into combat was in the Vietnam War, where they designated targets for laser-guided bombs. Since then, such devices have been used to determine distance to a target, to signal and communicate, and to disrupt optical devices of hostile forces.
The Jet Age
Speed was one of the primary considerations as the Air Force transitioned to an increasing reliance on jet propulsion. The Korean War was a major milestone in this transition.
The battle for air superiority reflected the end of propeller-driven fighters and the increased use of jet aircraft. As the war began, the swept-wing F–86 Sabre set a speed record of 670.981 mph — the aircraft entered combat on December 16, 1950.
Within the next decade, other aircraft types began to transition to jet propulsion. One of the most well-known is the B–52 Stratofortress strategic bomber. Although the program had its origins from the late 1940s, the first B–52 flew in December 1954. Capable of reaching a speed of 628 mph (546 knots) and carrying 43,000 pounds, the aircraft exceeded the original requirements.
On June 29, 1955, the Boeing Aircraft Company delivered the first B–52 Stratofortress to enter Air Force operational service. The eight-engine bomber was designed to drop nuclear weapons from high altitude. The B-52 became — and continues to be — an important part of the Air Force’s strategic bomber inventory.
The application of jet technology to the aerial refueling mission also occurred during this period. On June 28, 1957, the KC-135 Stratotanker was delivered to the Air Force. Able to take off at gross weights of up to 322,500 pounds, the jet tanker could cruise at the same speed as jet bombers while refueling, drastically reducing the time for in-flight refueling missions.
The transition to jet propulsion transformed the strategic reconnaissance mission during the Cold War even more dramatically. Working in secrecy in the early 1950s, Lockheed began the design of what would become the U-2 high-altitude, long-range reconnaissance aircraft.
The first test flight was in July 1955. The aircraft could fly 10-hour missions at top speeds of 600 mph to unprecedented high altitudes.
The origins of GPS can be traced back to the US Navy’s Transit navigation system in the 1950s to track latitude and longitude. At the same time, the Air Force was working on what was known as 621B, and the Army had a satellite navigation project. The Department of Defense joined the efforts in a single program that could track location in three dimensions: latitude, longitude, and altitude.
On December 18, 1958, the Air Force placed the first artificial communications satellite, a Project SCORE (Signal Communication by Orbiting Relay) vehicle, into low-earth orbit. The launch demonstrated the peacetime application of missile technology. The following day, the satellite broadcast a taped recording of President Eisenhower’s Christmas message — the first time a human voice had been heard from space. The projected duration of the orbit was 20 days and the orbit actually lasted for 35 days.
On February 22, 1978, an Atlas booster launched the first Global Positioning System (GPS) satellite. Operated today by the U.S. Space Force, GPS is freely accessible by anyone with a GPS receiver and has irreversibly changed the face of military operations and civilian navigation. Its first use in military operations was during the Persian Gulf War in 1991 before it was even fully developed, and it has remained an essential resource ever since.
Fly-by-Wire Flight Control
For 20 years, the Air Force Flight Dynamics Laboratory conducted a step-by-step research program in concert with industrial partners to make fly-by-wire possible. Beginning in 1956, engineers sponsored and participated in a graduated series of basic and applied research projects that culminated in the adoption of active flight control on the F-16 in the mid-1970s. The F-16 was the first operational fly-by-wire aircraft designed as such. The total direct investment in Air Force fly-by-wire research prior to its design in then-year dollars is slightly under $20 million, inexpensive considering the pervasive results.
Since fly-by-wire technology enables active control of aircraft, they can be unstable in one or more axes. There are resultant advantages in maneuverability and reduction of the weight of control surfaces — advantages for both military and civilian aircraft. There are additional advantages for military aircraft in terms of survivability and weapons delivery. At the simplest level, the mechanical cables leading from control devices such as stick and rudder pedals are eliminated and replaced with sensors at the base of a control column and other sensors to keep track of aircraft attitude and acceleration. Inputs from the sensors are sent to a computer that calculates the appropriate commands to actuators that will accomplish the pilot’s desires. Since all control signals are carried by wires rather than steel cables, the technology came to be called “fly-by-wire.”
The same technology that gave the F-16 its unprecedented maneuverability has improved the reliability, performance, and safety of commercial airliners and “drive by wire” automobiles.
Remotely Piloted Aircraft (RPA)
The first operationally significant unmanned aerial vehicle (UAV) from the Air Force was the Lightning Bug, which was based on a target drone. The Lightning Bug was used for tactical reconnaissance and flew nearly 3,500 sorties during the Vietnam War. The RQ-1 Predator was developed as a joint program managed by the Navy and operationally run by the Army. The Air Force took operational control of the program in 1996. Between 1996 and 2004, the RQ-1 Predator system evolved into a formidable combat support asset and was involved in every major military operation. It logged nearly 100,000 flight hours, with 68% of those hours flown in operational environments.
The MQ-1B Predator is an armed, multi-mission, medium-altitude, long-endurance remotely piloted aircraft that is employed primarily as an intelligence-collection asset. With its weapons, it provides a unique capability to perform strike, coordination, and reconnaissance (SCAR) against high-value, fleeting, and time-sensitive targets. Predators can also perform intelligence, surveillance, reconnaissance, close air support, combat search and rescue, precision strike, route clearance, target development, and terminal air guidance.
The MQ-1 Predator continues to be one of the military’s most requested systems, assisting in the execution of the global war on terror by finding, fixing, tracking, targeting, engaging, and assessing suspected terrorist locations.
The F-16 emerged from the Air Force’s Lightweight Fighter Program (LWF), an experimental prototyping effort that took place between 1972 and 1975. The LWF program was noteworthy for its rapid execution, innovative management strategies, and successful approach to technology transition.
The purpose of the prototype program was to determine the feasibility of developing a small, lightweight, low-cost fighter and determine what such an aircraft could do. The demonstration, if successful, would give the Air Force the option of complementing the F-15 with a lightweight, lower-cost day fighter.
The first YF-16 was rolled out December 13, 1973, and its first scheduled flight was made on February 2, 1974. The first supersonic flight was three days later, and the top speed of Mach 2 was reached on the 20th flight on March 11.
Also in 1974, a competition was announced to design a stealth fighter. By April 1976, Lockheed had won both phases of the design competition and was given the go-ahead to build two prototype aircraft of roughly 10,000 to 12,000 pounds. The purpose of the prototypes was to show that Lockheed could achieve in flight what it had achieved in scale-model tests on a radar cross-section measurement facility. The aircraft was a key demonstrator for what became the operational F-117 stealth fighter in 1983. The first flight occurred on December 1, 1977, a little more than 19 months from go-ahead in the program.
Lightweight aircraft technologies also have been developed to enable a wing to morph its shape to flight conditions. Conventional aircraft are generally designed and optimized for a single mission. The Variable Camber Compliant Wing (VCCW) demonstrates enhanced maneuverability that can increase wingspan without structural weight penalty, reduce drag, reduce noise, and maximize mission range by more than 10%. This technology may also control a tailless aircraft in roll, pitch, and yaw using continuous lift and drag distributions, which would reduce antenna signature by removing the vertical tail.
In 2016, the Air Force invented and patented a weapons-grade steel alloy (AF9628) that reduces cost and improves the performance of many air-delivered weapons. The formulation removed an expensive ingredient that had been believed to be necessary for the alloy’s strength. Now produced entirely in the United States, this steel has helped the Air Force realize a 50% cost savings on materials for many of its current weapons systems. The additively manufactured steel has already proven stronger than the traditionally produced AF9628. The Army is using this steel as armor for personnel and vehicles.
During WWII, designers and manufacturers produced aircraft engines far more powerful than could have been imagined during WWI. With the addition of turbo superchargers, the liquid and air-cooled engines reached higher power and altitudes and jet engines appearing at the end of the war took aerospace propulsion to a new level. Propeller-driven combat aircraft gave way to more-powerful jet engines after WWII. As a result, the Korean War became known as the first “jet war.”
Boeing’s B-47 bomber, first flown in 1947, was a six-engine, swept-wing aircraft flown by the Air Force. This gave Boeing the engineering and financial basis to create the Model 367-80, a prototype for the 707 passenger plane.
A Bomber for Generations
The B-1 bomber was first envisioned in the 1960s to combine the Mach 2 speed of the B-58 Hustler with the range and payload of the B-52 — eventually replacing both bombers.
Rockwell International won the design contest for what emerged as the B-1A and initial plans called for 240 of them to be built; however, the combination of high cost and early work on the stealth bomber significantly affected the need for the B-1 and the program was canceled in 1977.
The program was restarted in 1981 by President Ronald Reagan, largely as an interim measure while the stealth bomber entered service. In January 1982, the Air Force awarded two contracts to Rockwell worth a combined $2.2 billion for the development and production of 100 new B-1 bombers. This led to a redesign as the B-1B, which had lower top speed at high altitude of Mach 1.25 but improved low-altitude performance of Mach 0.96.
The electronics were also extensively improved during the redesign and the airframe was improved to allow takeoff with the maximum possible fuel and weapons load. The B-1B began deliveries in 1986 and formally entered service as a nuclear bomber in 1986. By 1988, all 100 aircraft had been delivered. The B-1B is expected to continue to serve into the 2030s, with the Northrop Grumman B-21 Raider to begin replacing the B-1B after 2025.
Precision Guided Munitions
Operation Desert Storm demonstrated that dust, smoke, and cloud cover could hinder the effectiveness of precision guided munitions. The Joint Direct Attack Munition (JDAM) guidance system was designed to eliminate that hindrance.
The JDAM is a tail kit that fits on a normal “dumb” bomb and contains an Inertial Navigation System that utilizes GPS technology and can update its trajectory all the way to impact. It can be launched from more than 15 miles from the target. Operation Allied Force in 1999 saw the combat debut of the JDAM. Thanks to the combination of this new munition and the combat debut of the B-2 that carried them, Operation Allied Force was a revolution in warfare, featuring the combined accuracy, low cost, and all-weather capability of the JDAM.
On September 18, 2000, the Air Force accepted the first production CV–22 Osprey, a tiltrotor aircraft that combines the vertical takeoff, hover, and vertical landing qualities of a helicopter with the long range, fuel efficiency, and speed characteristics of a turboprop aircraft. The self-deployable aircraft offers increased speed and range over other rotary-wing aircraft, enabling Air Force aircrews to execute long-range special operations missions. The CV-22 can perform missions that normally would require both fixed wing and rotary-wing aircraft
A New Force in Space
The U.S. Space Force was established December 20, 2019, when the National Defense Authorization Act was signed into law, creating the first new branch of the armed services in 73 years. The establishment of the Space Force resulted from widespread recognition that Space was a national security imperative.
The Air and Space Forces unite under the Department of the Air Force and are inextricably linked in defense of U.S. investments and freedom of operation in space. Space missions, billets, and monetary resources from 23 Air Force units have been transferred to the Space Force. Operations, acquisition, and sustainment for some space systems currently distributed across the Army, Navy, and the Office of the Secretary of Defense will be merged.
National Security Space Launch (NSSL) provides assured access to space for the nation’s most critical warfighting and intelligence capabilities. The Space Force, National Reconnaissance Office (NRO), and NASA have a coordinated strategy to certify new entrants to launch payloads and continue to work with different launch providers to reliably meet national requirements.
Space capabilities are woven into the fabric of daily life. Satellites connect people in every corner of the globe, monitor weather patterns, carry television broadcasts, and the timing and navigation services of the GPS constellation power global financial networks, enable international commerce, synchronize cell phone networks, and optimize critical infrastructure.
According to General John W. Raymond, Space Force Chief of Space Operations, “Space has moved from a benign environment to a recognized warfighting domain. That change has occurred at the same time that space’s importance to military operations with global positioning, communications, and virtually every other aspect of joint operations has emerged as well. Our adversaries now have the advantages [in space] we’ve always enjoyed. It’s a different domain that required a different approach,” Raymond said.
Secretary of the Air Force Frank Kendall noted the critical role space plays in the nation’s security, the essential functions space enables in everyday life, and why access must be assured as space becomes more congested and contested. “It is impossible to overstate the importance of space-based systems to national security.”
This article was written by Linda Bell, Former Editorial Director, SAE Media Group (New York, NY).