Single Part Breaking Lost a $72 Million Drone

On August 11, 2011 Air Force ground controllers lost contact with one of the military’s most advanced — and expensive — drones, an EQ-4B Global Hawk as the jet flew high over Eastern Afghanistan.

Nine hours into an otherwise smooth communications relay mission using the Battlefield Airborne Communications Node (BACN), the plane was cruising at 51,000-feet above sea level 105 nautical miles northwest of Kandahar, Afghanistan — close to the border with Pakistan, in fact, the few news reports that emerged of the crash claim the jet actually went down inside Pakistan —   when a pilot from the 12th Reconnaissance Squadron out of Beale Air Force Base in California “lost all links with the payload,” according to a copy of the Air Force’s report on the incident that the service sent to DT. The pilot did everything he could to reestablish communications with the mammoth drone, but 25 seconds after losing communications, the plane began a high-speed fall to Earth. If plummeted so fast that “both wings and at least one of the lower aft fuselage fairings” were ripped off the jet as it fell. Three minutes later, the Global Hawk crashed into “remote, desert terrain approximately 4 nm from its last reported position and was destroyed,” reads the Air Force’s report. “the estimated loss is valued at 72.8 million.”

So, what caused this?

A single part — or Line Replaceable Unit, as the report calls it — came undone, interrupting the flow of electricity to the plane’s aileron and spoiler actuators — the tiny motors that control the movements of an aircraft’s flight control surfaces you know, the moving parts of the wings that control whether the plane climbs, dives, banks, rolls, etc. As expected, this disconnection rendered “the aircraft uncontrollable.”

(Critical parts that lose it like this one are called single points of failure, meaning that if these sometimes tiny and seemingly insignificant parts fail, the entire weapon system fails. Naturally, military equipment makers try o identify these and do all they can to ensure they won’t fail.)

Why did this single part become disconnected? “The board president also found, by a preponderance of the evidence, that the LRU [the critical part] installation methods were a contributing factor in the mishap,” reads the a summary of the report. Apparently, the screws holding the part in place weren’t tight enough and probably shook loose due to typical flight vibrations.

One other thing to note, the jet’s “avionics were not recovered from the crash site.” Let’s hope they were destroyed in the crash and the subsequent bombing of the wreckage by Air Force bombers and not scooped up by someone who could sell them to the Russians or Chinese.

Click through the jump to read a copy of the accident report.

EQ-4 Crash Final Report for Distribution

  • TMB

    105 miles northwest of Kandahar? That’s still inside Afghanistan, but headed in the direction of Iran.

    • I believe he meant Northeast, but that is what the report says, too. Maybe he meant that it crossed into Iran? That makes a lot more sense.

  • LtKitty

    Poor drone… it just goes to show how delicate complex technology can be. I fully acknowledge accidents are bound to happen, especially given how much more often these things are flown. However, the loss of a $72.8 million drone due to a few loose screws is an unacceptable mistake. Get ‘er done Air Force.

    • blight_

      It’s kind of shocking, especially when you’re used to good design producing results like an F-15 that can fly after an entire wing gets ripped off.

      • LtKitty

        Or the A-10. I am by no means an expert, though, but I think there’s certain tradeoffs and other variables that make the Global Hawk less resilient to disaster. I certainly would like to understand the design considerations because I hope to be working on super cool projects like the Global Hawk. I’m starting to learn that 20-20 hindsight is a blessing and a curse…

      • brianckramer

        @ 50,000 ft for 14,000nm and 42 hours?

        They each have a purpose, one isn’t better than the other. Plenty of 15’s have crashed as well.

        • blight_

          Fair enough, but many of those F-15 failures happen because the aircraft is old. The Global Hawk can’t possibly be that old…though I suppose being young means all the small things that can cause issues like this haven’t been found yet.

      • tiger

        Uh, want to re think that one? No, wing equals no fly.

        • blight_

          Though technically it was more like he landed with a wing totally shorn off, but that’s a pretty amazing “point of failure”.

          • 4FingerOfBourbon

            That is crazy….

          • blight_

            Indeed. To clarify, there was still a stub of the wing (perhaps two feet wide?) and it might have been enough to save the aircraft. Without it, perhaps not.

            But yeah. Comparing the failure of one doodad in a global hawk to getting a wing ripped off and still being able to land? Then again, if you have a UAV you have some built-in latency that prevents you from acting in real time in a responsive manner to keep your aircraft going.

          • tiger

            The Lord watches over crazy pilots with some handy flight computers. That guy had the “Right Stuff” in full effect that day. I’m ejecting…

        • ChuckL

          Sorry Tiger, but one F-15 did in fact suffer a mid-air collision with an accompanying escort and have a wing completely torn off. It occurred at high speed and the pilot recovered control. He found that at speeds above 250 knots he had adequate control and elected to try to land the plane as he felt that the information to be gained would be invaluable.

          The inspector who arrived insisted that this had to be a ramp strike until shown the chase plane films.
          The capability was attributed to the wide flat bottom of the F-15.

      • Splitpi

        The problem is the design, since it was never classified for manned flight the design and redundancy systems are less stringent. Thus allowing for more single point of failure items that lead to catastrophic failure.

        That is not to say that UAV’s cannot be robust, rather I think this was a case where design cost and maintenance trumped robustness. Perhaps the long term operational cost savings is greater than a catastrophic failure?

        Here’s a fun video of a Remote Controlled Semi-autonomous plane loosing 80% and still being controlled due to the avionics..

        • Splitpi

          If anyone cares… the Global Hawk gets 3.88 mpg. That really is not that bad of performance.

    • TMB

      When the F-16 was first fielded, there were crashes due to electrical failure because some of the wiring was rubbing against a protruding screw.

    • ChuckL

      Perhaps they should use spring loaded connectors as have been common on 75 ohm communication cables. I believe that the one I am thinking about is a TNC connector.

  • Yourfriend

    Or this is just a cover up for the Chinese testing out sat-com link jamming and such. Especially since they are viewing UAVs as a next gen threat.

  • Lance

    Its not the Federal Government w/o multimillion dollar mistakes. How ever a self destruct device may be needed more than anything else in drone improvements to prevent a Iran 2.0

  • Jazz ism

    It served its purpose and no pilots are lost. Expensive but that’s what drones are for. Easier to replace. Now we are receiving the actual benefit of the drone.

  • tiger

    Tip to the USAF: Go to a hardware store. Spend $2.50 for a tube of Loc-tite thread locker. Save $72. million…..

    • F-15 maintainer

      A spool of MS20995CY20 (0.020″) lock wire is even cheaper and doesn’t have a shelf-life like a thread locking compound does.

    • Darrel

      What happened to safety wire for electrical connetions? Guess I am OLD SCHOOL (1952, USAF.

  • itfunk

    Post should be entitled shoddy contractor maintenance costs another 74 million. No single part failed the contractors simply didn’t know how to install their own companies equipment properly.

  • Morty

    Where so far ahead tech wise, so do we really need another billion dollar project

    • tom mccoy

      We’re not that far ahead of China……we leave a model to reverse engineer behind every time one of these things crash.

  • Morty

    like the F-35 wasn’t enough to break the bank.

  • Skyepapa

    This accident is completely absorbed in a normal distribution. Move on.

  • TGR

    Accidents happen, especially to RPAs. There has been over $2B worth of RPAs lost in the last decade, and they are only going to get more expensive and still rain out of the sky

  • stephen russell

    Bad Parts QA? Fake part used??

    • blight_

      God knows.

      • joe

        Not connecting the damn thing in right. Note the use of the phrase “came undone”. It’s easy enough to do, given the amount of plumbing and wiring required to ready a combat aircraft after a service (I don’t know – but it’s not unreasonable to assume – that drones are as bad).

        More than enough combat aircraft have been lost over the years because a clamp has not been tightened enough, or been overtightened, or whatever. Nothing is necessarily wrong with the bits.

        • blight_

          I guess, but can they assess this from a smoking hole in the ground? Unless Global Hawks have armored black boxes…

  • passingby

    72 million? chump change.

    a broken Congress plus a broken White House have been costing the US and the world billions of times more.

  • Anom deplume

    Suggested followup questions for the members of the press to ask.
    1. What, if any, part of the component failure leading to this incident would have been prevented or mitigated if the GH had been truly ‘weaponized’ after it had been drafted into the operational inventory as a DARPA project?
    2. Has anyone in the GH program advocated increasing the redundancy of the control systems? If yes, who (govt, contractor)? Were the systems made more robust? If not, why not?

    • blight_

      1 and 2 would probably have led to increased costs; and even then might not have saved the Global Hawk from an accident tomorrow or next year. I think we’re building UAVs to lesser standards, anticipating that we can replace them quicker and with more turnover if they are cheaper, and if they destroy themselves in sufficient quantity via attrition.

  • The whole point of drones is to avoid human casualties in the risky everyday theatre of war, which includes minor part failures. Nothing is perfect but as far as weapons go the Global Hawk comes pretty close.

  • guest

    What does loss of electricity to an actuator have to do with the initial loss of all comm. links between controller and drone before it started its downward fall?

    • tiger

      Well Actuator is fancy name for a Servo motor like RC planes use. Without power, the control surfaces don’t move. I guess a open circut developed. So power was lost to the comunication links as well?

    • RunningBear

      The loss of the control surfaces would lead to the immediate loss (misalignment) of the satellite link. Similar to the function of ripping the wings off while falling 10 miles in three minutes, Sadly, also a BACN.

  • Dfens

    Sounds like pilot error to me. What, there’s no pilot to blame? It can’t possibly be the contractor’s fault. They hire lobbyists. They buy US Senators. It’s funny, manned airplane crashes are always the pilot’s fault, but manned aircraft crash at 1/100th the rate of unmanned vehicles. They never get credit for all the times they saved the US taxpayer millions of dollars, or rode an airplane into a smoking hole in a field instead of living through an accident that caused many ground casualties.


    You can have the highest tech product, but if your quality controls were lacking then it doesn’t mean crap. The THAAD missile from Lockheed Martin had these problems during the testing phase. The govt almost cancelled the program because of quality issues.

  • tom mccoy

    Do we blow these things up after a crash or are we providing China with a model to reverse engineer?

    • tiger

      Based on the one we lost in Iran, there is no self destruct system.

  • Uranium238

    Bummer… sure is a pretty looking drone =(

  • I worked on aircraft.
    All critical parts need to be safety wired.
    Someone needs to get in trouble for not requiring a fastener with a small hole for that.

    • MikeK

      What decade did you work on A/C? Did Orville and Wilbur know you by name? I PRESENTLY work on all types of heavy lifters and warbirds. We don’t always use safety wire, we use a variety of fasteners that are called out in the maintenance manuals and IPC’s.

      • Granted it has been a decade. And I was working on an antique onto itself in the F-14C.
        But whats great about safety wire is it was used on all critical mechanical parts and it was very OBVIOUS to see.
        I am glad you “use a variety of fasteners that are called out in the maintenance manuals and IPC’s.”,
        But my planes did not crash because something came loose…..

  • RunningBear

    Does the USAF actually fly any a/c without safety wiring the connectors and screws? I’ll check into current maintenance procedures. This is an extremely damning development for this organization. $72 million dollars buys a “heck of a lot” of safety wire and man-hours. Did they have flight insurance :) ??

    • PrometheusGoneWild

      Granted it has been over a decade and I was workIng on the F-14, which was an antique onto itself.
      Maybe they used “a variety of fasteners Called out by manuals and IC’s” but it still came apart and crashed.
      The nice thing about safety wire is just is VERY hard to miss if it is not on the part or put on improperly…
      Sometimes things are a certain way from hard lessons learned already.

  • JJAbrams

    This title is beyond lame on a military site.
    As if you said one fastener got loose on the wing and the plane fell, gee wiz, REALLY, a PLANE, no way.
    Hello, maintenance checks are rigorous for a reason.

  • Kuahiwi Bear

    In my day, LRU stood for Least Replaceable Unit…which basically meant the smallest part of a “gadget” that could be replaced..what – we’re getting so high tech nowadays that we have to change the meaning of an acronym? gimme a break..

    • Tom Scott

      In my military day, 1980-84, it was called Line Replaceable Unit. I’ve been at Hughes, Northrop, McDonnell Douglas and Boeing since. And they’re STILL called Line Replaceable Units. Just HOW OLD ARE YOU??? You’re awfully cynical too. I hope you’re retired.

    • Mikek


  • nraddin

    OK so it was not a communication issue, it was not a build in flight control and navigation issue. It was a flight control cable not put into place correctly by maintenance (Or poor design). This could have happened to any aircraft that runs fly by wire, it’s not a drone specific issue…. Seems like they would have some redundancy in those cables though.

  • fromage

    To mathesize: you’re saying that 72e6 * 1e9 >= the consequence of 1 Broken Congress + 1 Broken White House. You can do math, yes? And you’re not fond of hyperbole, you say?

    • passingby

      LOL. you are one heck of a broken math major and “mathesizer”

  • Mike

    “For want of a nail, the shoe was lost…” I live outside Beale AFB, and they’re taking this VERY seriously, believe me.

  • Edwardretusaf

    I guess no thought of a recovery chute.

    • tiger

      Nor did anybody think about 9-11 as a plan. While thinking out the box is great. We can’t think of every, “what if?” You could add a chute, but at what price? Added weight, lees fuel, less room for electronics. For the small benefit, there are many cons……

  • CGD

    1 word redundancy

    It works in the marine industry!

  • brian P

    Who knew a part that was supplied by the lowest bidder, probably China, failed?

  • MikeK

    How the hell would they KNOW that mount screws came loose and are responsible? I smell BS here, high and mighty BS! I postulate that something else went terribly wrong, for the umpteenth time with Global Hawk, and crashing in hostile territory is very, very unpleasant for high-value-persons in DOD! Somebody’s head had to roll, and, oh well, let’s just blame maintenance. Can’t be unproven after you put a JADAM on the wreckage! Hey and nraddin, if it’s fly by wire-there are NO CABLES!!

  • Ondafritz

    A fail safe self distruct explosive charge activated by an AWAC’s aircraft in the area should be standard procedure. That would be part if their IFF coded signals and a General officer in the AWACs aircraft would send the last radio message that the Drone receives.I strongly disagree wirh calling the technicial a pilot as most are enlisted personnel that fly these drones but thats another story for the funny papers



  • stealthb2

    for all of you armchair mxrs, give it up. what is the price of a U2 and pilot? what about or beloved SR, would that be better? if you have no clue of what an RPA is “supposed” to do after a set time of lost comm, dont second guess. Also, anyone that has been in and or around the USAF can predict a board’s findings 80-90% of the time. No pilot lost, mx fault-pilot lost, pilot error. Think, before you spew garbage from your pie-holes. BACN is out-performing expectations, in a very short time. AF Mxrs do what TOs tell them, complacency causes crashes. ’nuff said!

  • stacky77

    For the want of a nail the shoe was lost. For the want of a shoe the horse was lost . For the want of a horse the war was lost. Ditto Prometheus G.W. & RunningBear. I was an A&P Mechanic before training into Flight Engineer. From the B-29 all the way to the C-124 and the C-141. Cannon Plugs and or ANY electrical connectors “GET SAFETY WIRED!!” I live near Beale AFB, I’ll go see what the crew chiefs are doing these days!

  • Nam

    Online marketing – It’s about more than having a pretty website.

    An online marketing system is the perfect way to get started online, because you get to build your list and get educated at the same time.
    SEO is the most prominent tool to drive a huge traffic rate,
    as search engines really give closest attention to well-optimized

  • Hi there, You have done a fantastic job. I will certainly digg it and
    personally recommend to my friends. I am sure they’ll be benefited from
    this site.

  • You can correspond with them and find out if they can ship the required model to your place.

    Apart from these, the yacht charters in Croatia also offer catamarans for large family with
    children. Launched in 2010, built of steel and
    finished with a teak deck, is 20 meters long and is divided internally into 3 double cabins
    for guests (a suite in the bow, a VIP cabin and a twin bus) and a cockpit for the crew.

  • i believe the range between how vapers vape will continue to grow
    and I also feel extremely disheartened by this.