The U.S. Navy has publicly announced that it took delivery of its first NC-37B missile range support aircraft earlier in 2018. It is now headed to Raytheon, which will integrate a host of specialized mission equipment into the plane so it can keep missile ranges clear of hazards during tests, gather important telemetry data from those launches, and serve as a communications relay platform. The Naval Air Systems Command officially received the NC-37B, a modified Gulfstream G550 business jet, on July 30, 2018. Scramble Magazine had been the first to catch a glimpse of the plane, which is already wearing the colors of the "Bloodhounds" of Air Test and Evaluation Squadron Three Zero (VX-30), which is headquartered at Naval Base Ventura County in Point Mugu, California, the month before.

“Just getting to this point has been a process,” U.S. Navy Captain Steven Nassau, the program manager for the NC-37B project, said at an official acceptance ceremony. “Delivering the aircraft under cost and on schedule is a major milestone for such a complicated project.” In June 2018, Scramble had reported that the aircraft had received the Bureau Number (BuNo) 166379/100 serial number, but an undated picture the Navy released in September 2018 showed the aircraft was still wearing the U.S. civil registration code N544GD. It is entirely possible that the photograph predates when it received its BuNo. Whatever the case, the new jet will eventually replace one of VX-30’s aging NP-3D “Billboard” range support aircraft when it comes back from Raytheon with its full suite of systems.

At its core, the NC-37B uses Gulfstream’s G550 Airborne Early Warning (AEW) airframe configuration, also known as the Conformal Airborne Early Warning (CAEW) variant, which features an enlarged nose, new fairings on the fuselage sides, and a modified tail, among other features. Israel Aerospace Industries (IAI) originally helped develop this version for, as its name implies, aerial early warning missions with the modified airframe housing large conformal radar arrays, additional communications gear, and various other systems. The CAEW configuration also has extra power generation and cooling capabilities to support all the added electronics. Italy and Singapore now also operate AEW Gulfstreams based on this modified fuselage design. The U.S. Air Force looks set to follow suit with what could turn out to be an “EC-37B” and IAI might pitch the CAEW configuration to the United Kingdom as an option to replace the Royal Air Force's E-3D Sentry Airborne Warning And Control System (AWACS)

Gulfstream A basic overview of the G550 CAEW configuration.

The Navy’s NC-37B’s role will, in part, also involve air and maritime surveillance around U.S. government missile test ranges facing both the Atlantic and Pacific Oceans, such as the Pacific Missile Range Facility in Hawaii, Vandenberg Air Force Base in California, and Cape Canaveral Air Force Station in Florida. The Navy's range support aircraft keep an eye out for planes and boats deliberately or accidentally entering into the test area, which could prove dangerous for them and U.S. military personnel. Those intruders also present a potential operational security risk, as the missile and missile defense-related tests VX-30 supports are often highly sensitive, if not outright classified. These research and development events may also involve other top-secret systems, as well. For example, on May 26, 2014, a pair of NP-3Ds from VX-30 provided range support during a secretive Navy “flight test event” called Polar Bear. The objective of this test, which involved firing a sounding rocket, was to help evaluate the Cobra King missile-tracking radar system on the USNS Howard O. Lorenzen spy ship, Naval Sea Systems Command told The War Zone in 2017.

USN The USNS Howard O. Lorenzen "missile range instrumentation ship" spy vessel. The Cobra King radar arrays are visible at the stern.

To support this surveillance mission, as of 2014, Gulfstream was working under the assumption that the Navy’s NC-37B would carry a version of Telephonics’ AN/APS-143 X-band “Ocean Eye” radar in its nose. Versions of this radar are also found on the U.S. Air Force’s E-9A Widget range support aircraft and the Indian Air Force’s P-8I Poseidon maritime patrol plane. The latest iterations of the APS-143 are multi-mode systems that can function in search and synthetic aperture modes, the latter of which gives it imaging and mapping capabilities. Its search capabilities are powerful and precise enough to spot a life raft size object at ranges up to 25 miles away depending on altitude. However, in 2015, Gulfstream only said it was configuring the nose to accommodate a “notional search radar.” With the APS-143 still in production, it remains a very likely option.

Gulfstream A 2014 Gulfstream briefing slide showing the planned NC-37B nose configuration with the AN/APS-143C(V)3 radar.

The side fairings appear to be set aside for the telemetry arrays that will be able to monitor missiles in flight and help gauge their performance during tests. VX-30's existing NP-3Ds have various S- and L-band radars to perform this function and are able to track multiple, geographically separated targets at once. It is likely that NC-37B will also have still and video cameras to collect imagery of the launches. The NP-3Ds have Cast Glance still picture camera system and Cluster Ranger electro-optical full motion video camera systems. The pod on top of the plane's tail will house a satellite communications antenna and the fuselage will be covered in various other aerials associated with high-frequency and very-high-frequency radios, data links, ultrahigh-frequency navigational equipment, GPS, air traffic control and collision avoidance systems, and more. The communications and data-transfer systems will enable the aircraft to send surveillance and telemetry data back to personnel on the ground, as well as serve as a relay between those individuals and other air and sea assets present during a launch. We don't know what, if anything, might go in the fairing at the rear of the jet.

Gulfstream A Gulfstream briefing slide showing the NC-37B's antenna layout as of 2015.

The Navy also says that the CAEW configuration will provide room add in new and improved systems in the future, which will help the service readily upgrade and expand the NC-37B’s capabilities as necessary, which could help save money in the long run. Just replacing the old NP-3Ds with a G550-based aircraft will help trim costs given the improved fuel efficiency and lower overall operating costs of the newer aircraft. At the same time, since the NC-37B does not appear to share many, if any, missions systems with the standard G550 CAEW configuration, so Raytheon will still face a major integration task getting the various radars and other equipment that are unique to the aircraft into the airframe within the space available. The Navy has not disclosed how long it expects this work to take, but has said that it expects the plane to reach initial operational capability by 2021. We will hopefully get to see more of this interesting and important aircraft as it moves closer to entering operational service. Contact the author: jtrevithickpr@gmail.com