Since it replaced the Bureau of Naval Weapons in 1966, Naval Air Systems Command (NAVAIR) has ordered, tested, and developed an impressive variety of aircraft and weapons. Many made aviation history, others were steps toward long-sought capabilities. From the biggest to the fastest, the strangest to the slowest, every system represented an opportunity to learn.

NAVAIR went a step further when the X-47B conducted the first-ever autonomous aerial refueling of an unmanned aircraft in April 2015, completing the final test objective under UCAS-D.

The number of aircraft and weapons programs undertaken by NAVAIR in the last five decades is so large that we can only highlight a handful here. They represent just a slice of the superlatives and successes made every day across NAVAIR.

 

X-47B

Though it seems to have happened only yesterday, the testing and development of the Northrop Grumman X-47 is a watershed in naval aviation. A series of firsts, beginning with the first-ever full-size unmanned aircraft carrier-based catapult launch from USS George H. W. Bush (CVN 77) in May 2013, were accomplished during NAVAIR’s management of the Unmanned Combat Air System Demonstrator  (UCAS-D) program from 2011 to 2015.

The UCAS-D program had its origins in the early 2000s, but NAVAIR expanded its initial scope to demonstrate carrier launches and recoveries, as well as autonomous inflight refueling. A test program that began at Naval Air Station (NAS) Patuxent River in 2012 saw autonomous precision approaches and runway arrested landings moved to sea trials in 2013. The first carrier-based arrested landing, also aboard the Bush, was made in July of that year.

NAVAIR went a step further when the X-47B conducted the first-ever autonomous aerial refueling of an unmanned aircraft in April 2015, completing the final test objective under UCAS-D.

NAVAIR UCAS Program Manager Capt. Jaime Engdahl observed that, “We have been using the same [carrier] landing technology for more than 50 years now, and the idea that we can take a large UAV [unmanned aerial vehicle] and operate in that environment is fascinating.”

 

E-6B Mercury

What’s the biggest aircraft tested and developed by NAVAIR? The Boeing E-6B Mercury has that distinction.

Based on the Boeing 707-320 (and subsequent E-3A), the E-6B is a communications relay and strategic airborne command post aircraft. Initially conceived as the E-6A to replace the EC-130Q in relaying National Command Authority (NCA) instructions to fleet ballistic missile submarines, a mission known as TACAMO (“Take Charge and Move Out”), it has since taken on a dual mission. The E-6B also provides broader airborne command, control, and communications between the NCA and U.S. strategic and non-strategic forces.

The first Mercury rolled out in December 1986 and made its first flight in February 1987. After initial flights with Boeing in Seattle, it was ferried to the Naval Air Test Center at Patuxent River for systems development testing. Operational test and evaluation was undertaken by VX-1 and initial deliveries to VQ-3 took place in August 1989. All 16 E-6As acquired were modified to E-6B configuration beginning in the late 1990s. Among other modifications, the E-6B is equipped with an airborne launch control system, capable of launching U.S. land-based intercontinental ballistic missiles.

 

V-22 Osprey

As mainstream as it now seems, the Bell Boeing V-22 Osprey tilt-rotor was among the stranger large aircraft programs at NAVAIR.

The V-22’s roots stretch back to tiltrotor designs of the 1950s and 1960s and specifically to the Joint-service Vertical take-off/landing EXperimental (JVX) aircraft program for which the Navy/Marine Corps took the lead in 1983. The first V-22 rolled out in May 1988, though the Army left the program that year. Despite funding and political challenges, prototype development continued through the early 1990s. Flight testing of four full-scale development V-22s began in early 1997 at NAS Patuxent River but fell behind schedule.

Sea trials were completed in 1999, but a pair of accidents in 2000 resulted in the loss of 19 Marines and the grounding of the Osprey. NAVAIR made numerous hardware, software, and procedures changes to the aircraft, however, and the V-22 survived to be fielded by the USMC in 2007. Software upgrades increased the maximum speed from 250 knots to 270 knots, increased the helicopter-mode altitude limit from 10,000 feet to 14,000 feet, and increased lift performance.

In 2015, NAVAIR tested rolling landings and takeoffs on a carrier in preparation for the Osprey’s role as a carrier onboard delivery aircraft.

 

AIM-54 Phoenix

If ever a missile was identified with the Navy, it was the AIM-54 Phoenix. Like the F-14 Tomcat that carried it, the air-to-air missile became famous.

The Phoenix’s long range (more than 100 miles) gave the F-14 the greatest standoff engagement capability of any fighter in the world for decades. Teamed with the Tomcat’s AWG-9 fire control system, it was the first operational radar-guided air-to-air missile that could be launched in multiple numbers against several different targets from an aircraft. In 1973, the AIM-54 set a benchmark with the first full-scale testing on an F-14 on NAVAIR’s Point Mugu Sea Range. Within 38 seconds, the Tomcat launched and simultaneously guided six Phoenix missiles to six separate targets 50 miles away, scoring four direct hits.

The Hughes Aircraft Company began development of the Phoenix in 1962, intending it for the F-111B. In 1966, an A-3A Skywarrior performed the first full-scale test over the Pacific Missile Range near San Nicholas Island, California. When the F-111 was abandoned by the Navy, the F-14 got the AIM-54, which debuted operationally in 1974. NAVAIR worked through the late ’70s to develop the improved AIM-54C, which joined the fleet in 1981. Though it never shot down enemy aircraft in U.S. hands, the Iranian air force, which had received F-14s and AIM-54s in the mid-1970s, claimed several Phoenix kills during the Iran-Iraq War. The AIM-54 retired in 2004, two years prior to the Tomcat.

 

F-14 Tomcat

NAVAIR has tested and developed many high-performance airplanes in 50 years, but none was as fast as the F-14 Tomcat. In relatively clean configuration and maximum afterburner, the Tomcat could achieve Mach 2.34 (1,544 mph @ 49,000 feet).

After the Navy determined the F-111B wouldn’t meet its fleet defense fighter needs, NAVAIR issued a request for proposals for the Naval Fighter Experimental (VFX) program in 1968. VFX called for a tandem two-seat, twin-engined air-to-air fighter with a maximum speed of Mach 2.2. Grumman was awarded the VFX contract in 1969, and the Tomcat first flew on Dec. 21, 1970, just 22 months after Grumman was awarded the contract.

The original design airframe life for the F-14 was 6,000 hours, but was later extended to 7,200 hours. Until its 2006 retirement, it continued to be the Navy’s “Harley,” fast and furious.

It reached IOC in 1973 after a challenging test program at Grumman’s Calverton, Long Island facility that saw numerous compressor stalls of its TF30 engines and ejections. Further testing at Patuxent River and China Lake featured broad evaluation, dissimilar air combat maneuvering, and weapons tests. Upon its introduction, the F-14 was the largest and heaviest American fighter to fly from an aircraft carrier.

More than 700 F-14s would ultimately be produced, with approximately 79 delivered to Iran prior to the 1979 Iranian Revolution. NAVAIR oversaw development of the F-14 A-Plus (later F-14B) and F-14D Super Tomcat in the 1980s. Late in its career, the F-14 took on the strike role after NAVAIR adapted the Low-Altitude Navigation and Targeting Infrared for Night (LANTIRN) targeting system to allow the Tomcat to deliver laser-guided bombs. It was subsequently nicknamed the “Bombcat.”

The original design airframe life for the F-14 was 6,000 hours, but was later extended to 7,200 hours. Until its 2006 retirement, it continued to be the Navy’s “Harley,” fast and furious.

 

X-35/X-32

“X-planes” have always been a high-profile part of NAVAIR activity. Some have been highly successful, others have yielded lessons from failure, and still others have led to aircraft whose value has yet to be determined. Each of these themes spun out of the Joint Strike Fighter competition for which NAVAIR provided a crucial stage.

The Joint Strike Fighter (JSF) program began in 1996, arising out of the early 1990s Common Affordable Lightweight Fighter and Joint Advanced Strike Technology projects. JSF called for the Navy, Marines, and Air Force to use a single, stealthy airframe capable of conventional, STOVL, and carrier-borne operations.

A JSF competition in 2001 pitted Boeing’s X-32 and Lockheed Martin’s X-35 demonstrator aircraft against each other in a fly-off at several facilities including NAS Patuxent River, Maryland.

Boeing designed the X-32 around a large one-piece carbon fiber composite delta wing and a direct-lift thrust vectoring system (similar to the AV-8B) for the Marines’ STOVL requirement. Due to the heavy delta wing design of its prototypes, Boeing demonstrated STOVL and supersonic flight in separate configurations. Lockheed’s X-35B used a more complex alternative, incorporating a remote shaft-driven lift fan powered by the main engine. The design generated more lift thrust than possible with only direct exhaust gases, greater payload, and greater range.

The X-35 prevailed in large part thanks to its performance flexibility in a single configuration (converted from the X-35A) – able to take off in a short distance, go supersonic, and land vertically in one flight. Though costlier, the X-35 was judged to have better mission potential across three variants.

Fifteen years later, NAVAIR is still at work refining the F-35B/C, the latter having accomplished its first arrested landing on an aircraft carrier on Oct. 2, 2015.

A footnote is that two of the JSF demonstration aircraft, Boeing’s X-32B and Lockheed’s X-35C, now reside at the Patuxent River Naval Air Museum.

 

CH-53E Super Stallion

“Biggest” is a relative term, but when you’re talking helicopters, there’s nothing larger in the American military than the CH-53E. The Super Stallion grew out of an early 1960s Marine requirement for a heavy-lift helicopter. The Sikorsky CH-53A Sea Stallion met that requirement, but the need for even heavier lift in a variety of environmental conditions led to the development of the CH-53E Super Stallion, the largest helicopter NAVAIR has yet tested and developed.

NAVAIR ultimately developed the MH-53E Sea Dragon for the airborne mine countermeasures role, modifying the aircraft’s digital flight control system and increasing its fuel capacity and endurance. MH-53Es became operational in 1986.

In October 1967, the Marine Corps issued a requirement for a helicopter with a lifting capacity 1.8 times that of the CH-53D that would fit on amphibious warfare ships. Sikorsky had been at work on a heavier capacity version of the CH-53D, which added a third turboshaft engine and a more powerful rotor system with an additional (seventh) rotor blade. The Marines funded development of a prototype in 1968, and by 1970 the Navy joined the program.

The first YCH-53E flew in 1974. It featured a fuselage stretched 6 feet, 2 inches over the Sea Stallion. New rotor blades, a stronger transmission, a larger, canted vertical tail-rotor assembly, and a third engine yielded a helicopter that could lift 17.8 tons and reach 170 knots. In August 1976, two CH-53E prototypes arrived at the Naval Air Test Center at Patuxent River for flight test. The first production CH-53E flew in 1980, and fleet introduction began a year later.

NAVAIR ultimately developed the MH-53E Sea Dragon for the airborne mine countermeasures role, modifying the aircraft’s digital flight control system and increasing its fuel capacity and endurance. MH-53Es became operational in 1986.

The CH-53K King Stallion, which first flew in October 2015, will soon join NAVAIR’s inventory of test aircraft. With new engines, avionics, software, and structures, the King Stallion will be a huge helicopter but its footprint will actually be narrower than the CH-53E’s, though it will lift more than twice the load of the Super Stallion.

 

X-31

Not all test and development work leads to operational systems. Sometimes NAVAIR undertakes broader applied research. Such was the case with the Rockwell-Messerschmitt-Bölkow-Blohm X-31.

Two X-31s were built for the early 1990s Enhanced Fighter Maneuverability program, which was conceived to test fighter thrust vectoring technology. A cranked, canard delta-wing aircraft without horizontal tail surfaces, the X-31 relied on three paddles directing the exhaust to control pitch and yaw. In 1992-93, the X-31 achieved controlled flight at a 70-degree angle of attack and successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver.

Its success led to a second program in the late 1990s called VECTOR, a joint venture between NAVAIR, Germany’s defense procurement agency BWB, Boeing’s Phantom Works, and DASA. NAS Patuxent River was the flight test site from 2002 to 2003, where the X-31 flew extremely short takeoff and landing approaches first on a virtual runway at 5,000 feet in the sky to ensure that an inertial navigation/GPS system combo could accurately guide the aircraft with the centimeter accuracy.

VECTOR culminated with the first ever autonomous landing of a manned aircraft with high angle of attack (24 degrees) and short landing – a precursor for what the X-37B would achieve with no pilot over a decade later.

This article was first published in NAVAIR: 50 Years of Naval Air Systems Command, 1966-2016 magazine.