How a large U.S. Navy UAV crashed in Maryland, from 18,000 feet

How a large U.S. Navy UAV crashed in Maryland, from 18,000 feet

On June 11, a massive Navy surveillance drone plummeted into swampland on an island in the Chesapeake Bay on Maryland’s eastern shore. The unmanned aircraft had a 45-foot fuselage — as long as a luxury motor coach — and a wingspan of more than 100 feet.

The closest populated area to the crash site is several miles away and no one was injured, though the disaster attracted news helicopters from local TV stations that videotaped the burning wreckage.

The Navy investigation into the catastrophic failure was completed this summer, according to records obtained by C4ISR Journal through a Freedom of Information Act request. The probe showed that the unmanned plane was filled with almost 6 tons of fuel shortly before takeoff and had only been briefly airborne. After intermittent trouble, it lost control at about 18,000 feet and pilots at computer terminals at Naval Air Station Patuxent River, Md., could no longer direct the aircraft as it plunged toward the ground.

Though the aircraft — a Broad Area Maritime Surveillance-Demonstrator, or BAMS-D — was the property of the Navy, it was operated by civilian contractors working for Northrop Grumman, the UAV’s manufacturer. The BAMS-D is a maritime version of the Air Force’s RQ-4A Global Hawk.

The cause of the accident was found to be mechanical — a faulty actuator for the UAV’s ruddervator, a combination rudder and elevator, common in V-shaped tails.

But the actions of the Northrop Grumman pilot in command violated emergency procedures, according to the Navy commander overseeing the probe. Failure to follow procedures could have produced “disastrous results,” the commander wrote. Though it was controlled by civilian contractors in Virginia, the aircraft was technically under the command of the Navy’s Patrol and Reconnaissance Wing 2 based in Hawaii.

This crash came as the Federal Aviation Administration is under increasing pressure to integrate UAVs into civilian aviation by September 2015, as required by Congress. While drones are a new world for the FAA, the Bloodsworth Island crash is a reminder that the armed forces have extensive experience with unmanned aircraft. In addition to the BAMS-D, there have been several other large UAV crashes in the U.S. — Reapers and Predators — and experts say it would be wise of the FAA to use lessons from those crashes as the agency looks to make rules for civilian drones.

Interview delayed

In the BAMS-D accident, the prominent civilian role in a military operation made for an unusual investigation into the crash. In fact, no military personnel were even interviewed.

“The unique makeup of the BAMS-D program made for some minor difficulties in conducting the investigation,” according to the report.

“In the case of the mishap all of the personnel directly involved were civilian contractors,” the report explains. “This caused delays in conducting interviews while Northrop Grumman determined if they desired to have lawyers present for the interviews. The final [determination] was that it wasn’t necessary as the investigating officer was not a JAG officer.”

The investigation shows that the BAMS-D took off from Patuxent River on what was supposed to be a four-hour mission. The mission brief said it was primarily a “confidence flight,” with a secondary purpose of “crew proficiency.” The co-pilot told the Navy investigators in a statement after the crash that the reason for the flight was “to exercise the equipment and the plane.”

Workers filled the aircraft with almost 12,000 pounds of fuel in the morning.

The aircraft took off at 11:51 a.m., and things soon soured. The pilots, at computers at the naval air station, received notice of a fault in the ruddervator actuator. The actuator is the motor that moves the ruddervator back and forth.

First, the pilots commanded the flight to climb to 60,000 feet. This type of aircraft is “autonomous” and the pilots control it at computer keyboards, rather then with joysticks that simulate cockpit control. Soon, instead of 60,000 feet, the pilots instructed the UAV to get to 25,000 feet altitude.

Then they turned the flight to the east “to avoid overlying populated areas.” They decided to return the flight to the airfield because of the problems.

At 12:02 p.m. the pilot instructed the plane to descend from 25,000 feet to 18,000 feet. The pilots received a “Guidance Control 8 Fault,” from the aircraft, and apparently that’s when the plane went out of control and began “a right-hand spiraling turn.”

A chart in the investigation records shows that at this point, the plane had a pitch of 74 degrees, which means its nose was heading almost directly to the ground.

The co-pilot told the investigating officer that he lost the transmission link to the plane.

“At this point, MCE [mission control element] was not able to effect control on the aircraft,” he said. Meanwhile, he said, the pilot was on a headset “conveying that he had link but no longer could affect control and the plane was in an out-of-control flight regime.”

A field technician told investigators that “I heard the pilot inform ATC [air traffic control] that he had lost control of the aircraft and the aircraft was not responding to his commands.”

At 12:06 p.m., about 15 minutes after takeoff, the BAMS-D sent its last transmission to the ground station just as it was about to impact the wetlands on Bloodsworth Island, at a 55-degree angle.

The cause was found to be mechanical. Northrop Grumman said the problem was an “anomaly” in the power card for the ruddervator actuator, which caused “intermittent failure.”

But the Northrop pilots, according to the report, didn’t completely follow proper procedure.

The investigation found that “the pilots followed the published emergency procedures with the exception of climbing above 40,000” feet. That procedure “allows the pilot the plots to conduct controllability checks.”

The commander of Patrol and Reconnaissance Wing 2 wrote that “failure to adhere to emergency protocols did not produce disastrous results in this particular event; however, future breaches of established procedures could produce a different outcome.”

The civilian pilot’s name is redacted in the papers, but the commander recommends that his “contract be thoroughly reviewed and the appropriate remediation be instituted.”

It is unclear how thoroughly the FAA looks at the military’s experience with UAVs as it prepares to integrate unmanned systems into the national airspace.

Sean Cassidy, vice president of the Airline Pilots Association, which is heavily engaged in the issue, said the FAA should be actively reviewing incidents like this one.

“It doesn’t take a genius to surmise what would happen,” he said, “if this was to happen over a densely populated area.”

Cassidy said that in general, DoD has been cooperating with the FAA as it gets ready for its rulemaking. He said UAVs should be certified in the same way manned aircraft are and that pilots should receive equivalent training.

The National Transportation Safety Board has no authority to investigate military aircraft crashes, but an NTSB spokesman said the Navy had shared “safety information that is privileged” about the incident.

“They shared information that we can use for safety purposes,” the spokesman said, “but not release.”

Lt. Aaron Kakiel of Naval Air Forces command said that on top of this investigation, a separate safety investigation was completed. He says the fleet was inspected after the accident, “to make sure this doesn’t happen again.”

In an email, a Northrop Grumman spokesman said the company “fully supported the U.S. Navy’s investigation into the BAMS-D incident and we’ve helped implement corrective actions identified in the report.”