With the cost of Northrop Grumman’s RQ-4 Global Hawk having declined in recent years, the US Air Force has reversed course and says it is now ready to retire its manned Lockheed U-2s in fiscal year 2016.

The move, which would shift the USAF’s high-altitude intelligence, surveillance and reconnaissance (ISR) mission entirely on to the wings of the Global Hawk, still needs Congress’ blessing.

However, if approved, it would mark the first time a USAF mission that was formerly performed by a manned aircraft is assumed solely by an unmanned air vehicle (UAV).

Analysts say the plan is driven by politics, but suggest it shows commitment by the military to UAV technology.

They also note that the Global Hawk’s history of reliability issues and need for substantial upgrading raises questions about whether the platform is ready to assume a leading role.

“There will be some degradation of capabilities, because Global Hawk will need upgrades to improve all-weather capabilities and some sensors,” says Phil Finnegan, from consulting company Teal Group.

“This is the first time an unmanned aircraft has completely replaced a manned aircraft. This is a bit of a milestone,” Mark Gunzinger, analyst at the Center for Strategic and Budgetary Assessments, told Flightglobal earlier this year. “It’s a sign [the Department of Defense] is serious about development of an unmanned force in the future.”

Larry Dickerson, senior defense analyst at Forecast International, notes Global Hawks have historically been more expensive to operate than U-2s, and not as reliable.

He adds that the full capability of the Global Hawk’s sensors remain partly unknown, due to the secrecy of the programme, but calls the type a “very sophisticated” aircraft with notable benefits over manned aircraft.

For instance, Global Hawks can fly for around 30 hours, resulting in an “on-station” time that can’t be matched by U-2s, Dickerson says.

“It doesn’t help that Global Hawk is so expensive, but it does so much and carries so many sensors,” he adds. “You can’t put some poor guy up in an aircraft for 30 hours and fly a pattern.”

Global Hawk U-2 - USAF


The military has said its plan to ground the U-2s – revealed in its FY2015 budget request, released earlier this year – was driven by budget cuts and Global Hawk cost improvements.

“Over the last several years, [the Department of Defense] has been able to reduce the Global Hawk’s operating costs,” Defense Secretary Chuck Hagel said during a 24 February speech. “With its greater range and endurance, the Global Hawk makes a better high-altitude reconnaissance platform for the future.”

In March, USAF assistant deputy chief of staff for operations, plans and requirements Maj Gen James Jones told reporters all U-2s will be grounded in FY2016 under the plan.

He called the decision “a close call”, noting that military budget cuts preclude the service from operating both platforms.

“It’s not unusual for new systems to have challenges, but [Global Hawk] has matured,” he added.

Jones also praises the Global Hawk’s range and endurance, and added that the USAF plans to operate the aircraft for up to 40 years.

“We are going to keep this platform for decades. When we talk about the money we will save, it is across the projected lifespan of the platform,” he says.

But the Global Hawk needs upgrades – and they will not come cheap. The military projects spending about $1.8 billion in the next five years on Global Hawk modifications, research and development, according to budget documents.

Funds will go towards improving reliability and enhancing the aircraft’s ground station technology, enhanced integrated sensor suite (EISS), synthetic aperture radar (SAR), airborne data computer and mission planning system.

The USAF is also improving the aircraft’s ability to operate in icing and other adverse weather conditions, and has said it must spend $500 million on a “universal payload adapter” that would allow Global Hawks to carry the U-2’s sensors.

The US military has purchased roughly 50 Global Hawks since 2002 at a cost of more than $10 billion, including research and development, according to budget documents.

Those aircraft include derivatives like the US Navy’s MQ-4C Triton and NATO partner aircraft.

Global Hawk procurement chart

“Over time Global Hawk may prove up to the test, but right now the U-2 is still superior in certain mission sets,” Mackenzie Eaglen, from public policy group American Enterprise Institute, tells Flightglobal. “Any upgrades to get the Global Hawk to meet this standard are still years away.”

She notes that Gen Curtis Scaparrotti, head of US forces in South Korea, told lawmakers in March that U-2s have unique capabilities which make them better suited than the Global Hawk at detecting threats from North Korea.

U-2s carry the “senior year electro-optical reconnaissance system” (SYERS), which captures images in seven electromagnetic spectrum bands.

This allows U-2s to detect landscape, buildings and other objects that are invisible to the human eye, and to collect images through dust, haze and other atmospheric obstacles.

Global Hawks, by comparison, have EISS, which includes electro-optical and infrared sensors and SAR, and an airborne signals intelligence payload (ASIP), which can identify and locate radar and other signals.

Eaglen says the USAF’s plan remains “primarily about politics”, and predicts Congress will be supportive.

She adds it is possible Congress will appropriate funds to allow the Global Hawk to reach parity before the U-2s are retired – although she is doubtful that a compromise can survive next year’s budget battle.

Teal's Finnegan calls the service’s decision to keep its Global Hawks “quite a turnaround in the course of a year” – a nod to the USAF’s previous plan.

In its FY2013 budget request, the USAF said it would keep its U-2s and divest 18 Global Hawk Block 30s, which it said were more expensive to develop and sustain than the manned type.

According to the service’s total ownership cost database, Global Hawks cost $6,710 hourly to operate, compared to $2,380 for U-2s, as of July 2011.

Around that time, USAF officials cited reliability problems with the Global Hawk, and said its electronics were less capable than equipment on U-2s.

Although Congress blocked the retirement plan, a 2011 report from the Office of the Director of Operational Test and Evaluation (DOT&E) offered support to the USAF’s position, finding that Global Hawk Block 30s were “not operationally effective for conducting near-continuous, persistent [ISR]”.

The report said the aircraft’s ASIP “provided a limited operational utility” due to technical proficiencies, training shortcomings and other factors.

Global Hawks achieved an effective time-on-station rate during initial operational tests of just 27% – less than half the requirement – and the fleet could provide only 40% of requested ISR coverage under low operational tempos, the report stated. It did note, however, that Global Hawk’s Raytheon-made EISS met most operational requirements.

Northrop Grumman declined to comment, but in a 2011 statement said the Global Hawk reached a 90% “mission effectiveness” rate, and that the aircraft’s systems had been improved.

It also called comparisons between the U-2 and Global Hawk's costs flawed, saying internal company analysis determined the USAF shifted U-2 costs on to Global Hawks.

Forecast International's Dickerson says problems like those experienced by the Global Hawk are typical of other new systems.

He notes that the wars in Iraq and Afghanistan generated major demand for UAVs, which then drove the development of aircraft like the Global Hawk, General Atomics Aeronautical Systems Predator, AeroVironment’s RQ-11 Raven and AAI’s RQ-7 Shadow.

Those systems were still in their “infancy” during the last decade, and issues arose as they entered combat deployment, says Dickerson. “They were all having problems,” he adds.

Recent DOT&E reports indicate some of the Global Hawk’s issues have been addressed, however. A 2013 report says the USAF “has corrected most [Global Hawk] reliability and availability problemsm and implemented a limited number of previously-planned system improvements".

It adds, however, that improvements to the ASIP were delayed by the earlier plan to retire the fleet.

Lockheed Martin, which continues to fight for funding for its flagship F-35 programme, deferred questions about the U-2 to the air force.

However, earlier this year the company told Flightglobal that the U-2 remains the only high-altitude aircraft that can meet the USAF’s ISR mission requirements. Lockheed also noted that the 32 active U-2S and TU-2S trainers in the USAF fleet are relatively new, having been built between 1982 and 1989. Those platforms are 40% larger than the original 1950s-era U-2s, and feature improved General Electric F118-101 powerplants.

In addition, the company said the USAF has spent more than $1.7 billion on U-2S modifications since 1993, including a recent project that reduced the cabin pressure altitude from 27,000ft to 14,900ft.

And just last year, as many as 10 U-2s received a new communications payload that allows the aircraft to act as airborne network administrators, the company notes.

Although the USAF’s budget plan does not call for the service to order any more Global Hawks, the US Navy intends to buy 60 Tritons, beginning with four aircraft in FY2016.

Overseas demand for the Global Hawk and its derivatives also seems to be increasing.

In March, Australia announced its intention to acquire an undisclosed number of Tritons as part of its plan to replace its Lockheed AP-3C Orions.

One month earlier, Northrop Grumman said it was close to selling Global Hawks to South Korea, and confident in a sale of three aircraft to Japan.

Source: FlightGlobal.com