When drones fall from the sky

MQ-9 Reaper

The bigger, faster and more reliable successor to the Predator. It can fly as high as 50,000 feet and carry four Hellfire missiles, twice as many as the Predator. The Air Force expects to replace all its Predators with Reapers by 2018. The civilian version of the MQ-9 is called the Predator B. (Alberto Cuadra)

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The Air Force acknowledged that Predators crash more frequently than regular military aircraft, but officials said the drone’s safety record has improved markedly.

During its first dozen years of existence, the Predator crashed at an extraordinarily high rate — for every 100,000 hours flown, it was involved in 13.7 Class A accidents.

Since 2009, as the Air Force has become more experienced at flying drones, the mishap rate for Predators has fallen to 4.79 Class A accidents for every 100,000 flight hours.

Army crash rates

The Reaper has fared better than the Predator, incurring 3.17 Class A mishaps per 100,000 hours over the past five years.

Air Force officials pointed out that the crash rate for Reapers now approaches the standard set by two fighter jets, the F-16 and F-15, which over the past five years have posted Class A mishap rates of 1.96 and 1.47 respectively, according to statistics from the Air Force Safety Center at Kirtland Air Force Base in New Mexico.

“We’ve learned a lot about flying [drones] because we had to,” said Air Force Col. James Marshall, the safety director for the Air Combat Command. “War is a great motivator when lives are on the line.”

The Reaper has not been immune to deficiencies.

After one crashed during a training mission in California on March 20, 2009, Air Force investigators blamed a faulty temperature control valve in the oil system. A similar incident had occurred one month before.

Further investigation revealed that sliders in the valves had been installed upside-down. Air Force inspectors were even more surprised to learn from General Atomics that the firm had bought the valves from a Houston company that did not design its products for use in airplanes.

The valve “is not of aerospace grade. In other words, the thermostatic valve was designed specifically for industrial applications ONLY,” an Air Force investigator wrote in the accident report. “This thermostatic valve was not intended for aircraft.”

A faulty temperature control valve caused a Reaper to crash during a training mission in California in March 2009. (U.S. Air Force photo)

Unlike the Air Force, the Army does not make the argument that its drones are nearly as safe as regular planes.

In June 2013, Army safety officials posted a bulletin noting that their drones had crashed at 10 times the rate of manned Army aircraft over the previous nine months.

As bad as that number sounded, the officials said it actually understated the problem. Commanders were not reporting many drone mishaps, as required, to the Army Combat Readiness/Safety Center at Fort Rucker, Ala.

About 55 percent of the Army’s MQ-5 Hunter drones, which can carry weapons, have been “lost for various reasons” in accidents during training and combat operations, according to Col. Tim Baxter, the Army’s project manager for unmanned aircraft systems.

The RQ-7 Shadow, the smaller reconnaissance model that crashed into the Hercules cargo plane, has also been accident-prone. At least 38 percent of the Army’s fleet has been involved in a major accident, according to a Post analysis of Army safety statistics.