UV - Unmanned Vehicles

Defying the years: Global Hawk goes from strength-to-strength (Studio)

27th November 2019 - 10:00 GMT | by Studio

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This article is brought to you in partnership with Northrop Grumman

The Northrop Grumman RQ-4 Global Hawk has evolved greatly over the years, driven by technological developments and operational demands. Yet despite all these changes, it’s still recognisably the same platform that Alfredo Ramirez sketched on a piece of paper 25 years ago. 

At that time, Ramirez was a designer at Teledyne Ryan Aeronautical, which in 1995 was selected by the Defense Advanced Research Projects Agency (DARPA) to develop the platform that would eventually become the Global Hawk. 

Northrop Grumman acquired Teledyne Ryan in 1999, but Ramirez stayed with the company, and has been involved with the UAV ever since, serving today as Northrop Grumman’s Vice President, Engineering, Autonomous Design Center of Excellence. 

The platform went through an intense design phase, Ramirez explains, with designers considering flying winged variants to straight wing, propeller driven configurations, before settling on today’s aircraft.

ABOVE: Original Global Hawk sketch by Alfredo Ramirez.

‘It was pretty much everything under the sun,’ he says.

There are a number of obvious differences between the finished platform and the original ideas, Ramirez says; for example, the tail configuration has evolved from a conventional horizontal design to a V-tail.

However, there is a clear lineage between Ramirez’s first sketch and the platform that is flying today, from the radar antenna in the belly to the electro-optical/infrared camera.

‘There’s a strong resemblance to the final product,’ he says. 

ABOVE: The first Global Hawk in production at Ryan Aircraft.

The Global Hawk involved new thinking in many aspects, so the initial development brought a number of natural challenges. It required a great deal of composite design work – the wing, for example, is formed of bonded composites, with very few mechanical fasteners. 

Likewise, the systems engineering that went into the design ‘was kind of unique’, Ramirez explains, and had to take into account operations at high altitude, of the kind that had typically been seen with the Lockheed U-2 or the SR-71 Blackbird. 

This had to be balanced with cost. Beyond broad objectives, the only strict requirement the US government had was a unit flyaway price (UFP) of $10 million. 

Today’s aircraft are similar to the systems first produced about 20 years ago, at least from an external perspective.

Alfredo Ramirez

All other specifications could be adapted to meet this goal, Ramirez says, something that made the systems engineering ‘a little unique’. 

The designers had to evaluate changes and trade-offs against this financial target, ‘everything from the ground control station to the communication systems to the payloads that we needed to install and operate’. 

One of the ways that the company met this UFP was by installing synthetic aperture radar on all aircraft, while only some had an EO/IR camera. 

‘That was possible because in certain areas of the world cloud coverage limits your ability to take EO/IR images,’ he says. 

Today’s aircraft are similar to the systems first produced about 20 years ago, Ramirez adds, at least from an external perspective

ABOVE: First flight in 1998 at Edwards AFB, California, United States.

However, the newer platforms are larger – with a wingspan of 132 feet versus 116 feet – and heavier, going from 25,000 to 32,000 lbs, ‘because it has much more capability’. Additionally, there have been significant improvements in processing and payload integration. 

The September 11 attacks forced a rapid acceleration in Global Hawk’s deployment, with the systems available for use in Afghanistan just two months after the terrorist attacks. 

Avis Anderson, who was air vehicle assembly manager and now works on the Triton programme as Director of Sustainment, was involved with the development of Global Hawk from the beginning, setting up the factory floor that initially built the system in the late 1990s. 

Even before 9/11, Anderson remembers an intense working environment, with 12-hour days and weekends the norm.

ABOVE: The first international flight in 2001 to Australia.

‘Once I went in on Thanksgiving morning to swap out a nose landing gear and the only other guys on the factory floor were other engineers associated with that programme,’ he recalls. ‘We had a real commitment among the crew to build that first aircraft.’ 

This workload increased dramatically after 9/11. On 10 September 2001, the company had two aircraft in flight tests at Edwards Air Force Base, still painted white. But right after the attacks, the US Air Force immediately determined it wished to deploy the UAVs into the war effort. 

‘So, we pulled together a small cadre, government and civilian, most of whom had been maintaining the aircraft at Edwards, and we pushed it forward,’ he says. 

This acceleration involved a good deal of analysis, Andersen explains, from the impact of painting the radome on sensor ability to the logistics of getting the aircraft to the area of responsibility in the Middle East (eventually the deployment went via Australia, where the system had already flown). Andersen was himself part of the original deployment to Afghanistan. 

‘The group that went out there – air force and contractor – were among the most committed I’ve ever seen,’ he says. ‘That deployment was very, very rapid – you only have to look today at what it takes to prepare the deployment of a weapon system.’ 

Part of the success of Global Hawk is its flexibility, says Ramirez, a key element of the design from the beginning. This explains its success internationally, he said, and its deployment into new roles, such as the naval Triton variant. 

‘We’re just scratching the surface – there’s a bunch of other missions we’re looking at.’

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