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posted by cmn32480 on Wednesday July 29 2015, @10:46AM   Printer-friendly
from the the-dangers-of-being-a-test-pilot dept.

The National Transportation and Safety Board (NTSB) has found that a mix of pilot error and design flaws led to the crash of SpaceShipTwo last year:

The crash of a Virgin Galactic spaceship last fall in California's Mojave Desert was caused by pilot error and design problems, the National Transportation and Safety Board announced Tuesday after a nine-month investigation.

NPR's Geoff Brumfiel reports the NTSB found that SpaceShipTwo broke apart during a test flight on Oct. 31 because the co-pilot prematurely unlocked a section of the space plane's tail used in braking. The pilot survived, but the co-pilot, Michael Alsbury, was killed.

"But investigators found that SpaceShipTwo's design was also to blame. NTSB board member Robert Sumwalt says proper safeguards to prevent such human error weren't in place," Geoff says.

Detailed summary at Wired. Richard Branson's statement [video] in response.


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  • (Score: 5, Informative) by VLM on Wednesday July 29 2015, @01:10PM

    by VLM (445) Subscriber Badge on Wednesday July 29 2015, @01:10PM (#215428)

    You linked to the press release. That's OK. The actual report / presentation is at

    http://www.ntsb.gov/news/events/Pages/2015_spaceship2_BMG.aspx [ntsb.gov]

    and is in the form of multiple PDFs of multiple powerpoints (I shit you not, corporate technology culture is laughable sometimes).

    The story in the report is subtly different than the press release. True the immediate cause of breakup was improper manipulation of control surfaces. However, critically, the failure was in the training process / procedures.

    The failure was almost exactly analogous to deploying flaps above max flap speed (its been a long time since I took lessons, there is a fancy name similar to Vne but different) Anyway depending on your flight instructor and training doctrine at the time of training, you never even put your hand on the flap lever without eyes on the airspeed indicator such that the speed isn't above and in the (yellow?) bar on the airspeed, and you could recite from memory what that speed is. Its like how you never touch the power switch of a drill press or lathe without touching the chuck key first (as in, its not currently attached to the chuck, which would be really bad) Needless to say if everyone who ever flight trained on a mere 172 knows this and even remembers it twenty years later, a dude flying a rocket today would be pretty familiar with the general concept of not deploying flaps while going so fast it rips the wings off, so the concept of not feathering the tail or it disintegrates the plane would be pretty easy to train up on, but the report indicates they did a relatively shitty job of it.

    The specific failure mode is not training the pilot etc up on this peculiarity of some weirdass feathering tail airplane.

    The problem with designing something like that is you could bulk it up to make it strong enough to handle anything, but it'll be too heavy to get off the ground, or you can automate it, but then programmers will kill someone or the hardware will inevitably fail. Also with something this experimental, practically every flight is focused on emergency abort modes and its not entirely understood when you'll have to intentionally do something "weird" to avoid a worse scenario.

    So its kinda an inevitable loss, not this specific loss, but do risky stuff, people gonna unpredictably die. Which in a way is good news. Its not like the basic concept is a fail, or criminal negligence, or some hunter shot at it, or the failure was discovered after passenger rating rather than by test pilots.

    The long term solution is to get more flights and more data so you can design a tougher to disintegrate ship and use actual flight data to partially or fully automate that specific flight control. Or in summary, test pilot work, which is exactly what they were doing anyway.

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  • (Score: 2) by bob_super on Wednesday July 29 2015, @04:26PM

    by bob_super (1357) on Wednesday July 29 2015, @04:26PM (#215531)

    > Or in summary, test pilot work, which is exactly what they were doing anyway.

    One could argue that the loss of only one of the two pilots is a success of sorts. Something really bad happened, but not all life was lost, therefore the overall design is not fundamentally flawed.

    • (Score: 2) by VLM on Wednesday July 29 2015, @05:11PM

      by VLM (445) Subscriber Badge on Wednesday July 29 2015, @05:11PM (#215552)

      Eh pretty much. I'd say a design failure scenario would be modeling and ground testing made them claim the wings fall off if you deploy flaps above 100 knots, and you deploy at 80 knots and the wings fall off anyway. Or we thought it would be stable but it goes into uncontrollable flat spin at high altitude. Pitch-roll coupling like the ancient old X-3? How about placing a giant liquid fuel tank to the side of a multi-segment solid rocket booster, like, what could possibly go wrong? Test pilots been killed by design issues like that, and its not the kind of thing you can patch around "eh just make that bracket bolt hole one size bigger and call it good". The X-3, LOL what a dog of a plane, I got to fly one in a simulator many years ago, what a POS, I guess they call it a learning experience for a reason, never design a plane like that again, I still remember it was like a flying telephone pole with a wound up rubber band for an engine and the pitch-roll coupling made it feel like I was fighting an autopilot on acid, that plane just sucked, a freakish flying gyroscope.

      This failure basically boils down to "never do that particular flight maneuver again" and train the hell out of it. Maybe a solenoid that energizes and locks the control lever in place if the airspeed is out of range unless some kind of "emergency override" button is simultaneously pressed. It should be safe to launch the next one like next month or so. Going all the way back to the drawing board could have required years or shut down the program.

      Something I miss in "modern" computer games is flight simulators that are realistic enough not to be a video game arcade port toy but unrealistic enough that the PITA issues of flying are no issue. Basically the computationally limited era of 80s sims, maybe with slightly better graphics.