Pentagon testers found a new version of the RQ-4B Global Hawk unmanned aerial vehicle cannot effectively conduct the type of persistent spying for which it was designed.

The Block 30 version of the Northrop Grumman [NOC] drone “is not operationally effective for conducting near-continuous, persistent (intelligence, surveillance, and reconnaissance) ISR as specified in the Air Force Concept of Employment,” according to the RQ-4B Global Hawk Block 30 Operational Test and Evaluation Report. The 70-page report, dated May 2011 and signed by Pentagon Director of Operational Test and Evaluation J. Michael Gilmore, was recently released by the Project on Government Oversight, a government-watchdog group in Washington.

“A RQ-4B Global Hawk Block 30 Combat Air Patrol (CAP) of three air vehicles and supporting ground stations cannot consistently generate or sustain long endurance missions to support persistent ISR operations,” Air Force and Pentagon testers concluded. “When operating at near-continuous operational tempos, the system provides less than half the required 55 percent Effective-Time-On-Station (ETOS) coverage over a 30-day period.”

The report further states that during a shorter, seven-day “mission surge” demonstration, the Global Hawk delivered 39 percent of requested ISR, when low operational tempos of up to three sorties a week with three aircraft were used.

The findings, from Air Force testers approved by Pentagon-level brass, offer other mixed testing results. The Block 30 Global Hawk’s Enhanced Imagery Sensor Suite (EISS) creates imagery “that meets or exceeds most operational requirements and provides actionable imagery intelligence (IMINT) products to operational users,” it says. Meanwhile, the Airborne Signals Intelligence Payload “provides a limited operational utility to detect, identify, and locate some threat radars and to detect some communication signals, but does not consistently deliver actionable signal intelligence (SIGINT) products to operational users due to technical performance deficiencies and immature training, tactics, techniques, and procedures,” the testers found.

“The RQ-4B Global Hawk Block 30 is not operationally suitable,” the Operational Test and Evaluation document concludes. “Global Hawk long endurance flights do not routinely provide persistent ISR coverage due to low air vehicle reliability.”

The report is based on assessments of operational testing conducted last October through December.

Northrop Grumman is “working closely with Air Force to ensure Global Hawk meets its cost and capability requirements,” company spokesman Randy Belote said yesterday. “Global Hawks have been deployed since November 2001, flying missions in five theaters today supporting military and disaster relief operations around the globe. These airframes have consistently performed as designed and continue to provide valuable information for the nation’s commanders in the field.”

Belote said the company will not comment “on specific government reports.”

The Air Force is part way through buying its 42 planned Block 30 Global Hawks. The aircraft program breached costs earlier this year, triggering a so-called Nunn-McCurdy review required by Congress (Defense Daily, April 14, 2011).