Grim “Reaper” News: US Drones Inexplicably Falling From Sky

Craig Whitlock has a long read in today’s Washington Post, digging into the issue of US drones suffering problems while in flight. These problems often result in the pilots having to steer the drones into remote locations to crash because they are unable to return to base:

A record number of Air Force drones crashed in major accidents last year, documents show, straining the U.S. military’s fleet of robotic aircraft when it is in more demand than ever for counterterrorism missions in an expanding array of war zones.

Driving the increase was a mysterious surge in mishaps involving the Air Force’s newest and most advanced “hunter-killer” drone, the Reaper, which has become the Pentagon’s favored weapon for conducting surveillance and airstrikes against the Islamic State, al-Qaeda and other militant groups.

The Reaper has been bedeviled by a rash of sudden electrical failures that have caused the 21/2-ton drone to lose power and drop from the sky, according to accident-investigation documents obtained under the Freedom of Information Act. Investigators have traced the problem to a faulty starter-generator, but have been unable to pinpoint why it goes haywire or devise a permanent fix.

Whitlock goes on to tell us that the Air Force alone saw 20 drones either destroyed or suffer major damage in 2015. Later he also tells us that the Army has its own smaller fleet of drones and it has suffered similar drone catastrophes, with four major crashes last year. Remarkably, if we go to the 20 year history of the Predator drone, Whitlock informs us that about half of the 269 Predators the Air Force purchased have crashed or suffered major damage.

As mentioned above, most of these crashes involve the starter-generator failing. The search for an underlying cause for the starter-generator failures has not been successful:

Working with engineers from General Atomics, investigators identified three parts of the starter-generator that were susceptible to breakdowns. But they couldn’t figure out why they were failing.

No pattern was apparent. Older units had failed, but so had brand-new ones. There was no correlation with operating locations or conditions. The Customs and Border Protection investigation blamed an “unknown factor” that was “likely external.

Oh my. What sort of “external” causes might be at work here? Surely it couldn’t be anything like what Iran experienced in its nuclear program, could it? In a remarkable coincidence, David Sanger has an interesting article today, speculating that US sabotage of Iran’s nuclear program may well have played a role in getting Iran to the P5+1 negotiating table. And, of course, no dirty hippies have ever suggested that US drones might be vulnerable to “external” shenanigans.

Meanwhile, the US is busily installing backup starter-generators on Reapers. Whitlock tells us 47 Reapers have gotten the retrofit and that the backup system so far has been credited with 17 “saves” where the backup kicked in to allow a drone to safely return to base when it otherwise would have been ditched.

21 replies
  1. haarmeyer says:

    “Identified three parts susceptible to breakdowns”, “numerous manufacturing quality issues” but we have absolutely no idea why a part which has a 100 year history in the automobile industry and is similar in concept to the main engine in a Tesla S-series or one of the hybrid engines in a Prius is experiencing a high failure rate? So they’re handing the problem back to the same company for redesign, while that company plainly blames the problem on not having a redundant part to kick in because that’s what happens when the parts fail on other craft?

    Why do I think this is probably more related to the C-suite at General Atomics having the same business philosophy as the governor of Michigan than it is to something more tantalizing and mysterious?

    Three parts which could fail? Oh, gee, it’s probably not the housing, and that kind of means there’s the windings, there’s the gearbox, there’s the brushes and there’s the power supply electronics. You could redesign all of them in probably a month using available information from other industries. Maybe you could just have those other industries examine the starter-generator with new eyes instead of hiding behind PR and redacting everything.

    Well, it’s nice to know my car is built to standards far beyond the new mil-spec.

      • haarmeyer says:

        The alternator in a car doesn’t. What these are is a re-use of the starter motor as a generator — or alternatively, using the generator as a motor when starting the craft. Generators have been around since the dawn of electrical time. Mil-spec generators that can withstand nuclear attack and cost tens of thousands of dollars have even been around for closing in on a hundred years now, too.

        They are really pretty simpleminded, having need for even less electronics than an alternator in a passenger car. Now maybe they need some more electronics to get a smooth computer used voltage source for the drone electronics. But there’ve been computers in passenger cars since the mid 80’s too. And transistor radios in cars since the 60’s, so that’s doubtful.

        Just don’t see the problem with creating a reliable generator aside from “numerous manufacturing quality issues”. Of course there’s a far higher possibility of boneheaded genius* due to the secretive monopoly practices of the defense industry than other industries.

        *boneheaded genius definition: For 21 years I drove my Chrysler manufactured car without ever allowing it to run out of gas as a matter of strict personal ritual. Why? It had a fuel delivery system developed by some over-eager geek at Chrysler in the 1980s where the fuel pump motor ran hot and was cooled by the gasoline in the gas tank, in which it was mounted semi-embedded. Run out of gas the motor burns out, causing tons of expense and waiting to get it fixed or a large gasoline ingestion risk if doing it in the driveway. Nobody else had ever figured out that the pump motor could be cooled by the gas tank. Wow, technological breakthrough! Boneheaded genius.

  2. orionATL says:

    starter-generator implies batterries does it not.

    batteries mean possibility of battery failure.

    as an aside, i wonder what those batteries weigh.

    • lefty665 says:

      Could be the generator/alternator provides most of the watts with a relatively small battery that acts as a buffer and reserve. Or maybe it’s a cut rate Chinese lion battery that burns like a cheap laptop or hoverboard. Curious that there are failures across drone models. That would seem to narrow the field of suspects.

      • OrionATL says:

        And burns like a hover board – and I’m not talking afterburner.

        Has there been any talk of charred remains :)

        • lefty665 says:

          You mean charred like in the lead jpg in the Wash Post article? “Burned beyond recognition” I believe is the term of art. But it’s usually applied to the crew, and in the case of drones they go home to dinner and live to crash and burn again another day. The poor Hellfire missile may not be so fortunate.

          • orionATL says:

            and the there’z the day we have drones over washington, just to protect the populace, mind.

            “look. mom. up in the sky. it’s a bird. ”

            ” no, billy, that’s a plane.”

            “oh. it’s a drone. ”

            ” it’s falling !”

            ” incoming !!! “

  3. orionATL says:

    so this defect might account for the sudden appearance of an american drone on a desert floor in iran some years back.

  4. lefty665 says:

    It’s clear that our DoD procurement squeezes the poor contractors so hard that they have to cut corners on the assembly line to avoid being forced into bankruptcy. Poor dears, what else could they do than to produce crap to show stockholders a better ROI?
    All in all it’s better they crash than continue to murder wedding parties, women, children and old people. I’d call it a policy upgrade.

  5. martin says:

    quote”And, of course, no dirty hippies have ever suggested that US drones might be vulnerable to “external” shenanigans.”unquote

    Dirty hippys? Good god your mean.

    quote”Oh my. What sort of “external” causes might be at work here? Surely it couldn’t be anything like what Iran experienced in its nuclear program, could it?”

    Hahaha. You’re really mean emptywheel.

    It looks like the same “starter/generator” thing was happening to Border Patrol drones as well, to the point they shut down the whole program.

    Maybe they can do what my dad did on his homebuilt experimental aircraft. He built an aluminum adapters to interface a Toyota 20R engine starter and generator to the Lycoming aircraft engine. Cost him all of $35. Of course..I submit the same thing would cost the USG $35k per…if not more.

    • P J Evans says:

      Cost him all of $35. Of course..I submit the same thing would cost the USG $35k per…if not more.

      Your father wasn’t doing it under contract to the government, with stockholders and a BoD wanting to see profits. Which is why government contracts are so detailed and why everything sold to government is marked up.

  6. Les says:

    There’s some speculation that the malfunction of the drones is also linked to the two boats captured by Iran.

    • Bob Close says:

      The starter gen is likely a RE/PM type with a PWM drive, that also serves as a regulator… If by chance there is an ultracapacitor on the bus, there is the possibility that some of them have been wired in the reverse polarity from what they were burned in. Ultracaps don’t have polarity but if they are wired in the reverse of what they were originally burned in at it can quickly bring their life down to hours and they can present a short to the generator which will collapse the field in the rotor stator gap leaving the power bus at zero…. this could be an intermittent problem with the ucap….

      • orionATL says:

        any guesses as to the function of this generator?

        why not use an alternator – lower weight, longer life?

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