Aircraft

Northrop Grumman set to develop tail-down UAV for DARPA's Tern program

Northrop Grumman set to develo...
Unlike this DARPA artist's concept, Northrop Grumman Tern would be a flying wing design
Unlike this DARPA artist's concept, Northrop Grumman Tern would be a flying wing design
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The Northrop Grumman Tern would take off from a tail-down position similar to this Lockheed XFV experimental VTOL aircraft from the 1950s
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The Northrop Grumman Tern would take off from a tail-down position similar to this Lockheed XFV experimental VTOL aircraft from the 1950s
Unlike this DARPA artist's concept, Northrop Grumman Tern would be a flying wing design
2/2
Unlike this DARPA artist's concept, Northrop Grumman Tern would be a flying wing design

The competition to fulfil DARPA's plan to turn US Navy destroyers and frigates into drone-launching aircraft carriers seems to be over as Northrop Grumman has unveiled its version of the Tactically Exploited Reconnaissance Node (Tern) Unmanned Aerial Vehicle (UAV). Based on the flying wing design, the Tern UAV lifts off vertically in a tail-down configuration and is designed to operate from the decks of smaller surface ships in the US Navy without the need for aircraft carrier-type runways.

At present, Northrop is keeping details about the Tern to itself. No image has been released, though a model was unveiled by Northrop to reporters at a press conference in Los Angeles on December 11. However, it is the latest step in the decades-long pursuit of opening up fleet aviation beyond traditional aircraft carriers.

One of the greatest unsung revolutions in naval operations during the Cold War was the installation of flight decks on the sterns of frigates, destroyers, and other ships that allowed them to operate helicopters. By giving these ships air power without relying on carriers or shore bases, their ability to see and fight stretched from the horizon to the limits of the helicopter's range and payload capacity.

In the past 15 years, this has been further augmented by the introduction of UAVs, but these have tended to be small, short-range aircraft of limited capacity compared to their manned counterparts. DARPA's Tern program is looking at how to achieve the same success with UAVs that are larger and longer range than something based on a helicopter and that will allow the persistent forward deployment of fixed-wing drones from small Navy ships anywhere in the world.

Named after the family of long-distance migrating seabirds,Tern is a joint program between DARPA and the US Navy Office of Naval Research (ONR). Its goal is to develop launch and recover systems for UAVs that can be installed inexpensively, but not irreversibly on standard warships as well as medium-altitude, long-endurance, unmanned aircraft comparable in size to a Reaper drone and capable of operating from a small flight deck in heavy seas up to Sea State 5.

Though few details have been released, such launch and recovery systems may involve catapults or a crane-mounted grapple system similar to one that the Royal Navy experimented with to see if Harrier jump jets could operate from frigates. As for the aircraft, they would be designed for long-range intelligence, surveillance, and reconnaissance. The UAVs would be capable of carrying a 272 kg (600 lb) payload and have a range of up to 900 nm (1,670 km).

Until recently, the competition to develop Tern was a two-horse race, but AeroVironment dropped out in September, leaving Northrop Grumman as the only entrant. Though the formal winner for Phase 3 of the program to build a working demonstrator won't be announced until early January, the odds now heavily favor Northrop.

The Northrop Grumman Tern would take off from a tail-down position similar to this Lockheed XFV experimental VTOL aircraft from the 1950s
The Northrop Grumman Tern would take off from a tail-down position similar to this Lockheed XFV experimental VTOL aircraft from the 1950s

According to Flight Global, the Northrop Grumman version of Tern is a flying wing with a wingspan of about 9.14 m (30 ft). Using contra-rotating blades for flight, it sits on its tail during take off like the experimental Lockheed XFV, which flew in the early 1950s. Under the terms of the DARPA contract, it's capable of not only launching from a confined space, but also transitioning to sustained horizontal cruising.

In a recent report, Chris Hernandez, Northrop's VP for research, technology, and advanced design spoke to Breaking Defense and said that if Northrop is tapped for the next phase of development, the next step will be to carry out powered wind tunnel tests to deal with the design's complex aerodynamics. This will be followed by the development of a full-scale prototype for demonstration sea trials in the Pacific Ocean using a barge or a decommissioned warship using a flight deck of similar dimensions to that of a destroyer.

Source: DARPA

5 comments
Bruce H. Anderson
There are a couple of small drones with VTOL that transition into fixed wing flight. This may be a matter of scaling up what is already out there.
Paul Gracey
The original purpose of flight decks on destroyer class vessels was an anti submarine drone helicopter. Those WWII vintage 'tin cans' did not have the room for a full sized helicopter hanger, and the drone had control problems back in that analog age, so newly built destroyers were built larger to hold actual manned helicopters. In the case of the tail sitting prototype fighters, which I saw in San Diego during my service years, I have since learned that those airplanes also had the need of extremely gifted pilots to operate as designed. The Lockheed version shown never did do a vertical landing If I recall correctly. All good ideas, in some ways way ahead of their time.
Stephen N Russell
Ideal for DD, CGs, Frigates, carriers alone. Lisc for NATO use. Equip with arms & for Recon role
CaptD
Look for electro-rail launched aircraft of all types to be the preferred method of launching aircraft since it will provide maximum initial airspeed with minimum deck space. As far as recovery goes, many current helicopters now have the ability to hover over a pitching deck while they are winched aboard saving their pilots from actually landing them, since they are continuing to "fly" them until their landing gear makes contact with the deck. This "winch aboard" would also make it easy to retrieve drones since they can be flown remotely while being recovered, instead of having to hover, which is is a far more difficult maneuver for pilots, since it depends upon far more engine power and fuel expended. I imagine future drone pilots hitting their HOME button and having coffee while monitoring their drone as it returns to its base and is winched aboard, being monitored via computer all the time for operational anomalies.
Nostromo47
Paul Gracey, you are right, the Lockheed XFV never did a vertical takeoff or landing. It did fly, however, taking off and landing using an outlandish strap-on conventional landing gear rig incorporating main landing gear legs that were as long as the wings. A competitive design built by Convair of similar configuration (tail sitter with a gigantic turboprop sporting contra-rotating props) was able to make vertical takeoffs and landings. Vertical landings in the Convair were apparently very hairy affairs since the pilot was essentially performing this critical maneuver while glancing over his shoulder, dangerously limiting his view. It was tough enough to do on a nice day at a naval air station. Imagine how this was to be done routinely on the pitching deck of a destroyer at sea in stormy weather. Both VTOL fighters were cancelled in the mid-1950's when the Navy was adopting supersonic jets.