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Electrical Malfunction Caused Global Hawk Crash

In addition to providing new details about the doomed flight, the records show that Navy investigators concluded that a mechanical failure caused the aircraft to spiral out of control.

The flight was scheduled for a total air time of four hours. But unbeknownst to civilian contractors operating the unmanned aerial vehicle from the ground or their uniformed overseers at Patuxent River Naval Air Station, it would end 15 minutes later across the Chesapeake Bay in a plume of smoke.

More than 1,000 pages of records obtained by The Daily Times via a federal Freedom of Information Act request shed new light on the June 11, 2012, drone crash near Bloodsworth Island in southern Dorchester County.

In addition to providing new details about the doomed flight, the records show that Navy investigators concluded that a mechanical failure — and not the crew’s actions — caused the aircraft to spiral out of control.

The crew managed to steer the ailing aircraft to one of the remotest parts of Delmarva before the crash, leading to no injuries on the ground. But the crew didn’t escape criticism altogether.

A high-ranking reviewer, Capt. Christopher Ramsden, faulted the flight’s civilian commander, whose name is redacted in the reports, for “failure to adhere to emergency protocols.”

That failure “did not produce disastrous results,” the Hawaii-based Ramsden wrote nearly two months after the crash. Still, he recommended that the Navy thoroughly review the pilot’s contract and take “appropriate remediation.”

Back at Patuxent, officials don’t appear to have implemented that recommendation.

“Capt. Ramsden’s comments did not say the pilot’s actions were causal to the mishap,” the Naval Air Force’s public affairs department said in written response to the Daily Times’ questions. “His comments stressed the importance of adhering to procedures and that in a different circumstance, not following procedures could lead to a different outcome.”

Ultimately, the crew was “not culpable in this event,” the statement read.

A spokeswoman for Northrop Grumman, the aerospace and defense contractor that supplied the crew and manufactured the Global Hawk RQ-4A drone, said the company doesn’t comment on Naval operations. But she forwarded a recent company press release heralding the drone model’s designation as having the cleanest safety record in the Air Force in 2013.

The 2012 crash still stands as one of the Global Hawk’s biggest black eyes.

The only crash

The southern Maryland station at the mouth of the Patuxent River is home to the Navy’s test pilot school, drone operations and principal research center for aircraft and support systems.

It remains the only crash to occur under the program in which the drone was operating. Since 2006, the Broad Area Maritime Surveillance Demonstrator experiment has been laying the technical groundwork for wider drone use by the Navy.

The Global Hawk is designed for high flying — up to 11 miles above ground, or 60,000 feet, according to the Navy. On-board cameras and sensors relay flight information via satellite to a flight crew on the ground.

The mission on June 11 was a top-to-bottom sensor check and training for the crew. The drone’s previous flight, on June 5, comprised four hours of routine flying.

Under sunny skies, the Global Hawk took off from Patuxent’s runway 6 at 11:51 a.m.

Trouble began early. Barely two minutes into the flight, the aircraft sent an alert that the right inboard ruddervator — a blade that steers the craft both left and right and up and down — was more than 6 degrees off from its proper position.

In the highly regimented world of the Navy’s air program, a contingency plan exists for virtually every event. In this case, the pilot working the controls is supposed to override the system to prevent right-hand turns and make the aircraft climb to above 40,000 feet, where smoother flying conditions can be found.

At first, the pilot followed protocol.

“We have a flight control malfunction,” the pilot radioed to the air traffic control tower at Patuxent. “Aircraft appears to be stable and controllable, but we are going to climb up and check it out.”

The pilot steered the drone to the left from its south heading to the east, taking it away from populated areas in St. Mary’s County.

But as the aircraft reached about 25,000 feet, more alarms went off. Here, reviewers would conclude later, the pilot went against the script — dropping the altitude instead of going higher — and directing the drone back to Patuxent.

The post-crash investigation found that, to descend as quickly as possible, the pilot threw the spoilers to a 40-degree angle, 5 degrees shy of their maximum position for a descent. Doing so could make the flight unstable when a ruddervator has failed, investigators noted.

“The aircraft is going to crash”

With the ruddervator and spoilers in conflict with each other, physics took over.

At 12:05 p.m., the 12-ton drone began spiraling to the right.

“We have lost control of the aircraft. The aircraft is going to crash. Mark our location,” the pilot said, according to a transcript.

It took a minute and a half for the now-useless drone to plummet 18,000 feet. It slammed into the marsh at 140 mph, its nose 55 degrees to the ground.

The investigation concluded that an electrical problem inside the ruddervator’s control mechanism was to blame.

The report faults the pilots for not climbing to 40,000 feet, as prescribed, to check the aircraft’s controls under stabler conditions. Instead, they skipped to the next step — landing as soon as possible — with disastrous results.

That failure to follow protocol “cannot be overlooked,” Ramsden wrote.

In response to the crash, the Navy temporarily suspended the program as it “modified and updated” its computer software to prevent similar problems from happening in the future, the Navy said in its statement. No changes were made in flight patterns since they are already conducted in restricted areas and monitored by radar, it said.

The Navy handlers emphasized that the drone program makes every effort to avoid flying over residential areas, among other efforts to minimize harm to people on the ground.

“”Mission operators continuously monitor the flight and have the ability to redirect the aircraft if necessary,” the Navy said.

TIMELINE OF DOOMED FLIGHT June 11, 2012

11:51 AM

Global Hawk takes off from runway 6 at the Patuxent River naval air base in southern Maryland.

11:53 AM

Two alarms go off, warning that the right rudder mechanism is out of position.

11:54 AM

Pilot tells the tower: “We have a flight control malfunction. Aircraft appears

to be stable and controllable,

but we are going to climb up and check it out.”

11:55 AM

The pilot puts the craft into a climb to 25,000 feet.

11:57 AM

The pilot steers the craft to the left, away from populated areas in St. Mary’s County.

12:02 PM

As more alarms sound, the pilot puts the craft into a descent on a heading back to Patuxent.

12:05 PM

The pilot tells the tower: “We have lost control of the aircraft. The aircraft is going to crash. Mark our location.”

12:06 PM

The craft crashes into a marsh in southern Dorchester County.