Point to Point

Mark Ayton visited the MQ-4C Triton Integrated Test Team at Naval Air Station Patuxent River, Maryland, to learn about this fascinating unmanned aerial system



Located in a purpose-built facility on board Naval Air Station Patuxent River, the Triton Integrated Test Team (ITT) is equipped with three air vehicles, a hangar wide enough to house three MQ-4Cs wingtip to wingtip (an MQ-4C packs a 130.9ft wingspan) and the different types of control station required for its ongoing flight test programme, including those to be used at forward operating sites.

There are many fascinating aspects to the MQ-4C Triton and its missions. Based on the Northrop Grumman RQ-4 Global Hawk, the MQ-4C looks very similar: but looks can deceive. Under the skin, the MQ-4C has strengthened wing structures and an anti-ice and de-icing system, and a suite of systems all of which make the Navy variant different from its Air Force brethren.

Throughout the second half 2015, the Triton ITT and Naval Air Systems Command’s PMA-262, the Persistent Maritime Unmanned Aircraft Systems Program Office, remained busy with the integration effort of the latest software load known as Integrated Functional Capability 2.2 (IFC 2.2) required for the Triton system’s first operational assessment (OA) between November 2015 through January 2016.

It’s worth noting the Triton ITT comprises personnel from both the developmental and operational test authorities based at Pax, Air Test and Evaluation Squadron 20 (VX-20) and Air Test and Evaluation Squadron1 (VX-1) ‘Pioneers’ respectively. Pax is the nickname for Patuxent River.

Operational Assessment

The OA involved six flights and about 60 hours of flight time testing Triton’s envelope performance and its sensor suite, comprising:

• A Multi-Function Active Sensor Active Electronically Steered Array (MFAS AESA) maritime surveillance radar to detect, identify and track surface targets and produce high-resolution imagery.

• An MTS-B electro-optical/infrared sensor, which provides full-motion video and still imagery of surface targets (the camera).

• A ZLQ-1 electronic support measures system, which detects, identifles and geolocates radar threat signals.

• An automatic identification system receiver, which permits the detection, identification, geolocation and tracking of cooperative maritime vessels equipped with AIS transponders.

The OA also provided an operationally representative environment for the Triton ITT to test the onboard line-of-sight and beyondline- of-sight datalink and transfer systems that provide air vehicle command and control and transmit sensor data from the air vehicle to the mission control stations (MCS) for dissemination to fleet tactical operation centres and intelligence exploitation sites.

All testing was conducted in an operational environment.

Over the course of the six flights, the crew were able to get Triton on station effectively and provide real-time updates to the Navy end user. Crews found ways to improve functionality for fleet operators using procedural changes and identifying tweaks to the software to build a better user interface – for example, reducing the number of command pushes required for a certain function – and deemed the performance of the sensors to be very good.

Explaining how an OA differs from operational test, Triton Deputy Government Flight Test Director Cdr Kevin Meinert said OA is an early look at the system in the operational environment that’s designed to provide the ITT and programme office with information to help guide the focus of continued testing leading up to the operational evaluation period.

Discussing the test activity during the six flights, Triton Integrated Program Team Lead Cdr Dan Papp said the flight test crews looked at: the stability of the sensors; the functional capability of the camera system; the full suite (radio, line-of-sight and satcom) of communication systems; sensors, communications and interoperability with a simulated surface combatant using the Surface Aviation Integration Laboratory (SAIL) at Pax; and the reliability of the aircraft – for example, any degradation of the mission systems.

Cdr Meinert said the SAIL was also used during the OA to simulate different types of US Navy aircraft – P-8 was one example – to simulate interoperability with Triton in the mission sets conducted during the six flights.

In terms of the camera’s capability, test crews evaluated their ability to detect a certain size of vessel and to detect and identify the type of ship from range using the radar. They also determined the range at which they could detect a small fishing boat or a patrol craft compared to the range at which they could detect and develop the position, course and speed of a larger, merchant combatant ship.

One objective of the OA was to operate Triton in a mission representative way, part of which involved changing altitude for differing conditions, especially the environmental conditions in the airspace and the sea state. Cdr Meinert said the OA was planned to determine capabilities of Triton so the system can be further developed and moved forward, so altitude changes were executed whether or not conditions precluded sensor prosecution of the target.

All six missions, the longest of which was over 12 hours, were flown in warning areas off the Maryland coast, extending to the southern Virginia Capes.


According to the FY2016 Annual Report by the Director, Operational Test and Evaluation (DOT&E) the Triton system demonstrated positive trends for sensor performance and reliability during the OA. The maximum detection and classification ranges for maritime targets exceeded capability development document requirements and the Triton crews were able to transmit video to the SAIL via common datalink. The system reliability is currently tracking the requirements set out in Triton’s system engineering plan and the test and evaluation master plan. The report also listed deficiencies in the Triton system revealed during the OA:

• Lack of due regard capability (capability to maintain independently prescribed minimum separation distances) for traffic de-confliction and collision avoidance. This is a critical mission capability for operation of the MQ-4C in civil and international airspace in support of global naval operations. Unsurprisingly, the DOT&E lists any limitation to this capability at the time of Triton’s initial operational test and evaluation (IOT&E) as an aspect that will reduce the effectiveness of the MQ-4C.

• Poor EO/IR sensor control.

• Poor electronic support measures interface.

• Difficulty managing the temperature of the radar.

PMA-262 intends to select a technical solution to provide traffic de-confliction and collision avoidance capability after Triton’s initial operating capability (IOC) declaration. Naval Air Systems Command is investigating alternative means of due regard compliance, including procedures and other cooperative avoidance systems already integrated in the MQ-4C in order to support Triton operations at IOC.

The engine exhaust and the empennage arrangement of the Triton make for an interesting photo. Mark Ayton

Working with Ships

In March 2016, the Triton ITT had the opportunity to work with a Carrier Strike Group led by the USS Dwight D Eisenhower (CVN 69) during Composite Training Unit Exercise (COMPTUEX), one of the standard pre-deployment training evolutions.

Cdr Papp said the ITT launched several missions during the Eisenhower COMPTUEX to provide the Carrier Strike Group commander with battle domain awareness. The Triton crew looked for a simulated enemy combatant, identifying it with the radar and camera, and streamed web-enabled fullmotion video of the combatant to the Carrier Strike Group commander in real time.

Cdr Papp said: “The streaming video was well received. Triton performed excellently and we were able to use all of the mission sensors – a great opportunity to interact with the fleet. A P-3 and a P-8 also participated, which gave a good foreshadowing of how Triton will integrate with the fleet in the coming years.”

On June 2, 2016, a Triton flew a test mission from Pax, during which the aircraft tracked a target with its MTS-B camera to build situational awareness of the battle space for a P-8 crew some distance away. Full-motion video of the target was successfully exchanged with a P-8 for the first time inflight via a common datalink.

MQ-4C BuNo 168457 on a parking spot prior to a mission. US Navy
This shot of MQ-4C BuNo 168457 shows the radome housing the Multi-Function Active Sensor Active Electronically Steered Array maritime surveillance radar. US Navy

Cdr Papp said: “In an operational environment, this would enable the P-8 crew to become familiar with a contact of interest and surrounding vessels well in advance of the aircraft’s arrival on station.”

According to Cdr Meinert, the VX-20 P-8 and the MQ-4 were both able to interoperate while conducting their respective test missions.

Last June was also significant for the MQ- 4C programme when the team undertook the first missions to expand Triton’s heavy weight envelope to a full fuel payload, a critical requirement if the MQ-4C is to attain a 24-hour flight duration. A noteworthy aspect of the Triton system is its objective capability to fly missions up to 24 hours in duration at altitudes above 52,000ft (15,850m) to enable its mission systems to monitor two million square miles (5.179 million square kilometres) of ocean and littoral areas at a time.

On the first mission a Triton, in heavyweight configuration, completed all test objectives while operating in a 20,000ft (6,100m) altitude band, followed by a second flight on June 14 operating in a 30,000ft (9,150m) altitude band.

Operating Triton

The fleet’s Triton concept of operations (CONOPS) is to have an air vehicle operating thousands of miles away from the control station, two of which are planned at two locations, Naval Air Station Jacksonville, Florida, and Naval Air Station Whidbey Island, Washington.

At Pax, things differ from the fleet’s CONOPS simply because the control stations are co-located with the aircraft, which means the Air Vehicle Operator (AVO) can operate as the local crew with the aircraft (UA) or as the remote crew. Once Triton is in fleet service there will be two disparate crews, one on detachment with the UA and an MCS at the forward operating base (FOB), and one back at the main operating base (MOB).

Like any other aircraft, a Triton mission starts with mission planning and preparation work between the crew, which comprises an AVO who is also the unmanned aircraft commander (UAC), a tactical coordinator (TACCO) and two mission payload operators (MPOs). The AVO has responsibility for the safe flight of the aircraft and its positioning for the tactical employment of the sensors; the TACCO is responsible for the coordinating the tactical picture; and the MPOs operate the sensors from their control stations. All members of the crew have pre-flight duties.

Cdr Meinert explained that before the aircraft is spotted (the colloquial term for parking the aircraft on a specific spot on the flight line), the crew start mission briefings covering the safety, specific items, tasks and goals of the day, as well as the particulars needed for the pre-flight.

Teams then start their respective duties whether at the aircraft or at their control station. At Pax River, the UAC goes down to the aircraft to conduct a walk around for pre-flight. That’s unique, because in the fleet the aircraft will be at the FOB. The difference between ops at Pax and the fleet’s CONOPS is the UAC will be at the MOB and will have to delegate the walk-around to the local AVO, someone who is qualifled to do that at the FOB. At, Pax the UAC is with the aircraft.

Cdr Meinert explained the paperwork involved: “As the UAC, once I’ve completed my walk around, I hand the aircraft over to the test controller, who is the person who ensures everything is buttoned up and secure on the aircraft. I then walk into maintenance control to sign the A sheet – the flight release – and take responsibility for the aircraft as released to me by maintenance control.

“Because a Triton aircraft can fly for much longer than a human being can safely operate, we use multiple crews for each of the multiple phases of the mission, so in the middle of the flight we turn over the crew. The Navy has had to change its operating procedures to allow for a change of aircraft operating commander in flight.

“As the signatory for the aircraft, I take another A sheet and release the aircraft to the next UAC who signs the second A sheet, which covers his phase. The handover process continues until the aircraft lands. I anticipate this will be the CONOP in the fleet.”

In fleet ops, the UAC will be at the MOB and the aircraft will be at the FOB, so who will sign for the aircraft?

“That’s a good question,” replied Cdr Meinhert, “and a concept the Triton fleet integration team must detail before we undertake detached ops.”

Mission Control Station

There are two Mission Control Stations (MCSs) used by the Pax-based ITT, a FOB MCS and a MOB MCS just like the fleet will use. The distance between the two at Pax is a matter of feet, not thousands of miles; otherwise they are the same as those destined for the fleet.

The intent for the AVO at the FOB, who is within line of sight of the aircraft, is to control the aircraft on the ground, perform the take-off and the initial climb-out. Control of the aircraft is then handed to the MOB. All control stations have the ability to control the aircraft and maintain command and control of the aircraft simultaneously. The intent of the CONOPS is for the FOB AVO to release command and control once it’s under the control of the MOB whose crews fly the mission. Upon return to base, the aircraft is handed back to the FOB AVO for the final decent, landing and ground taxi input.

MQ-4C BuNo 168458 features a straight wing.MQ-4C BuNo 168458 features a straight wing.

Autonomous Taxi

Control of a Triton aircraft is by keyboard, a mouse and a mission plan developed and built from the start spot to the shutdown spot, the so-called spot-to-spot. Commands given to the aircraft by the AVO are fairly straightforward: taxi execute, stop execute, take-off execute. Once taxi execute is given, the aircraft taxies to the runway autonomously in accordance with the mission planned route.

Explaining the system’s autonomy, Cdr Meinhert said: “If you command the aircraft to taxi, it will taxi. If it loses control from the control station, it will automatically stop; we can stop the taxi at any time. When it takes to the runway, it won’t take-off unless it’s given a direct command to do so, received from one of the two control stations.

“Automatic logic is built into the aircraft control system for an aborted take-off. There is also a manual abort command, which was used last year when an apparent runway incursion occurred as the aircraft was attempting to take off. The crew saw a likely threat to safety, made the call and selected the abort command. The aircraft stopped on the runway centreline.”

The visual cue on the incursion was given by officers in the ground chase vehicle that follows the aircraft as it taxies. “The crew in the vehicle keep eyes out for obstructions, and other aircraft or airfleld traffic in the way. They are in constant radio contact with the control stations. When the aircraft takes the runway, the car also takes the runway. When the aircraft releases the brakes, the car accelerates and, as best the driver can, keeps up with the aircraft, almost like a formation take-off. When the aircraft lifts off, the car exits the runway. The aircraft lifts off at just over 100kts [185km/h], depending on its weight, and can abort at take-off speeds between 90 and 100 kts [165 and 185km/h].

“For landing, we give the car crew warning. The driver sets up at the end of the runway holding short. As soon as the aircraft passes the car, the driver follows the aircraft in almost a formation landing.

“We run a take-off and landing data card just like any other aircraft. We know that we have enough speed and distance to attempt take-off or abort, and enough distance should we have to take off and make an immediate return to land.”


Once airborne, the aircraft follows its mission plan route. Local air traffic control (ATC) has details of the route, because it can be close to or different from the local departure and arrival patterns. What’s more interesting about ATC coordination is manual flying. Cdr Meinert said this takes extra coordination because there are no eyes in the aircraft: “We work with ATC just like any other aircraft to the point that we are in communication with them to ensure the aircraft remains in a safe position, especially in the event of any kind of malfunction.”

The mission plan is for autonomous control. The aircraft will follow the mission plan route autonomously and execute all instructions in the mission plan. However, the crew can manually control the aircraft at any time using different options, as Cdr Meinhert explained: “I can do something as simple as limit the altitude while it continues to follow the mission plan. If ATC instructs me to climb and maintain an altitude, I can manually enter a heading and the required altitude. Another manual control is the command for flying a left or right 360-degree orbit at a specific altitude.

“If I’m told to keep the aircraft within a certain sector of airspace, I can enter go-to waypoints that are different [from] those in the mission plan. These ensure the aircraft stays within the new area while continuing to fly on to the next mission plan way points, and if required by either ATC or command at a different altitude.

“If the control station loses the link, the aircraft has built in logic to autonomously recapture the mission plan and execute one of many different contingencies. These include flying itself home or in the event of an emergency flying to a diversion fleld if available, or to a ditch point where the aircraft will safely ditch away from areas of population. The contingencies are pre-programmed for emergency situations whether or not the aircraft is on the mission plan route.

“As AVO pilot, it’s my job to make sure the aircraft is tied to the correct logic point for the real-time situation. However, during the mission we can manually fly the aircraft using commanded airspeeds, altitudes, headings, tracks, 360-degree patterns in both directions to prosecute a target, or find, identify and follow the target of opportunity as needed.”

Once a target of opportunity is done with, the AVO can command the aircraft to return to its programmed route or, if the aircraft senses the AVO is no longer on the link, it autonomously returns to the mission plan and executes whatever contingency logic is appropriate for the situation.

Mission plan areas are wide because the Triton flies so high for so long, such that a request from the Carrier Strike Group commander to check a potential target of concern may already be covered by the mission plan area. That said, one future capability is to be able to upload a new mission plan in flight.


When an aircraft is at the end of its on station time and fuel load and must return to base, the Triton CONOPS is to replace it with another Triton, which should arrive on station to provide continuous coverage of the area of operation. Once close to its FOB, the aircraft descends into the terminal area and is handed over to the FOB AVO (although either control station can control the aircraft) and sets up for one of a number of approaches pre-programmed in the mission plan. Upon arrival at the initial approach fix, the landing gear is lowered and, if not done already, the sensors are switched off. At the final approach fix, the system switches to glide scope mode and lines up the aircraft with the centre of the runway. On approach, the aircraft uses radio altimeters and four different navigation controls, two of which are for air vehicle navigation (the aircraft and its logic know its geospatial location and its energy state), which control its approach flight with standard spoilers and engine throttle commands. When the system senses the runway, the aircraft flares, touches down, engages the brakes and stops on the runway centreline. If the system fails its own internal landing check, it waves itself off and climbs out and flies back in to the pattern to make another approach to land. A wave-off can also be manually selected by the AVO, who can also manually fly the aircraft around the pattern for another autonomous approach to land.

Maintainers assigned to the Triton ITT push aircraft 457 to the hangar. Mark Ayton
Aircraft 457 and 459 side by side on the Triton ITT flight line at Pax. Mark Ayton

Once the aircraft has stopped on the runway, the AVO selects the taxi command and the aircraft autonomously taxies to the shutdown spot as programmed.

Initial Deployment, Low Rate Production

The ITT will shift test activity to IFC 3.1 software (the build destined for Triton at the time it is first flelded) later this year in preparation for an early operational capability declaration with the first two aircraft in baseline configuration (without the multiple intelligence (multi-INT) capability) and a launch and recovery and maintenance team deployed to Andersen Air Force Base on Guam (the FOB) in early to mid-2018. The back-end mission crew will operate from their squadron facilities at Naval Air Station Jacksonville, Florida, home of Unmanned Patrol Squadron 19 (VUP-19) ‘Big Red’, the Navy’s first unmanned air vehicle squadron. Located in the 7th Fleet’s area of responsibility, Guam will be home to two MQ-4Cs in a baseline configuration for approximately two years. The ITT and PMA-262 expect the air vehicle will receive functionality improvements to the radar, electronic support measures and the automatic identification system during that timeframe, after which an early operational configuration is expected to be on the ramp.

In the fourth quarter of 2016 PMA-262 changed its acquisition strategy for the Triton system by moving its IOT&E from the fourth quarter of FY2017 to the fourth quarter of FY2020. The change was made to align with the development and flelding of the aircraft’s all-important multi-INT capability: Triton’s first operational configuration. The multi-INT system will provide Triton with electronic and signals intelligence capability, and includes sensors, supporting software and hardware, which permits processing of classifled, sensitive, compartmented information.

The multi-INT configuration will augment the maritime ISR capability currently provided by the P-8 Poseidon, and ultimately replace the EP-3 Aries II intelligence gathering aircraft for most missions, a main objective of Triton’s existence.

Following approval of the MQ-4C Test and Evaluation Master Plan given by the DOT&E in April 2016 to support the Milestone C decision, Under-Secretary of Defense for Acquisition, Technology and Logistics Frank Kendall approved Milestone C in August 2016. The Department of the Navy announced the decision on September 22. Milestone C approval is the green light for a US defence programme to enter into lowrate initial production.

On April 4, Northrop Grumman announced an MQ-4C assigned to the Pax-based ITT had completed a first flight loaded with an improved build of software. The new software load is designed to improve the aircraft’s Traffic Alert and Collision Avoidance System (TCAS), multi-aircraft control and additional operating modes of the MFAS AESA radar.

Maintainers walk with aircraft 457 as the tug-tractor driver edges the 130ft wide Triton into the purpose-built hangar at Pax. Mark Ayton