<story><title>Swiss Post Suspends Drone Delivery Service After Second Crash</title><url>https://spectrum.ieee.org/automaton/robotics/drones/swiss-post-suspends-drone-delivery-service-after-second-crash</url></story><parent_chain><item><author>jacquesm</author><text>&amp;gt; do you have any idea what part(s) are failing so quickly? The rotors, the motors, the battery?&lt;p&gt;It doesn&amp;#x27;t really matter what fails, what matters is that there is no way to do a controlled descent once anything goes wrong on a loaded drone because there is no margin for error. A drone this heavy relies on the whole chain of components functioning perfectly.&lt;p&gt;I&amp;#x27;m surprised it is as good as it is given the number of parts. If it were a winged drone you&amp;#x27;d at least have a chance to glide it to a safe spot, but a drone that is kept up by spinning props can only crash uncontrolled. There was a video of downing one in a more controlled way but the only fault it could cover was single rotor failure and even then the amount of control was very limited.&lt;p&gt;These things have absolutely no business over areas occupied by people.</text></item><item><author>crazygringo</author><text>Wow, that&amp;#x27;s shockingly low. The paper doesn&amp;#x27;t describe why -- do you have any idea what part(s) are failing so quickly? The rotors, the motors, the battery?&lt;p&gt;For commercial delivery service, it seems quite clear that we&amp;#x27;ll need either&lt;p&gt;1) &amp;quot;enterprise-grade&amp;quot; drones (like difference between consumer and enterprise SSD&amp;#x27;s),&lt;p&gt;2) reliable sensors to detect imminent failure before a flight,&lt;p&gt;and&amp;#x2F;or 3) easy replacement of failing parts.&lt;p&gt;I mean, for many hobbyists 100-200 hrs seems like a reasonable cost&amp;#x2F;benefit tradeoff... but not even &lt;i&gt;close&lt;/i&gt; for commercial delivery services.</text></item><item><author>sytelus</author><text>This could have been very ugly:&lt;p&gt;&lt;i&gt;the 10-kg drone suffered an uncontrolled crash “in a wooded area of   Zurich’s university quarter only 50 yards away from a group of playing kindergarten children.”&lt;/i&gt;&lt;p&gt;One of the things that few people are aware about is quadrotor MTBF is very low relative to other common vehicles. For many drones, the expectation for failure dramatically increases just after 100-200 hours of operation[1]. Figuring out points of failures, building systematic fault trees and increasing MTBF by order of magnitude or two would be big part of the drone delivery projects.&lt;p&gt;[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;catsr.vse.gmu.edu&amp;#x2F;SYST490&amp;#x2F;490_2014_SPDAV&amp;#x2F;DST-NSPDAV_USMA.pdf&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;catsr.vse.gmu.edu&amp;#x2F;SYST490&amp;#x2F;490_2014_SPDAV&amp;#x2F;DST-NSPDAV_...&lt;/a&gt;</text></item></parent_chain><comment><author>pfundstein</author><text>&amp;gt; what matters is that there is no way to do a controlled descent once anything goes wrong on a loaded drone because there is no margin for error.&lt;p&gt;Not entirely true. The drone had a parachute system to allow a controlled descent in situations like this and an alarm to alert nearby people to its descent. The problem here was that the parachute&amp;#x27;s single tether was severed shortly after deployment.</text></comment>
<story><title>Swiss Post Suspends Drone Delivery Service After Second Crash</title><url>https://spectrum.ieee.org/automaton/robotics/drones/swiss-post-suspends-drone-delivery-service-after-second-crash</url></story><parent_chain><item><author>jacquesm</author><text>&amp;gt; do you have any idea what part(s) are failing so quickly? The rotors, the motors, the battery?&lt;p&gt;It doesn&amp;#x27;t really matter what fails, what matters is that there is no way to do a controlled descent once anything goes wrong on a loaded drone because there is no margin for error. A drone this heavy relies on the whole chain of components functioning perfectly.&lt;p&gt;I&amp;#x27;m surprised it is as good as it is given the number of parts. If it were a winged drone you&amp;#x27;d at least have a chance to glide it to a safe spot, but a drone that is kept up by spinning props can only crash uncontrolled. There was a video of downing one in a more controlled way but the only fault it could cover was single rotor failure and even then the amount of control was very limited.&lt;p&gt;These things have absolutely no business over areas occupied by people.</text></item><item><author>crazygringo</author><text>Wow, that&amp;#x27;s shockingly low. The paper doesn&amp;#x27;t describe why -- do you have any idea what part(s) are failing so quickly? The rotors, the motors, the battery?&lt;p&gt;For commercial delivery service, it seems quite clear that we&amp;#x27;ll need either&lt;p&gt;1) &amp;quot;enterprise-grade&amp;quot; drones (like difference between consumer and enterprise SSD&amp;#x27;s),&lt;p&gt;2) reliable sensors to detect imminent failure before a flight,&lt;p&gt;and&amp;#x2F;or 3) easy replacement of failing parts.&lt;p&gt;I mean, for many hobbyists 100-200 hrs seems like a reasonable cost&amp;#x2F;benefit tradeoff... but not even &lt;i&gt;close&lt;/i&gt; for commercial delivery services.</text></item><item><author>sytelus</author><text>This could have been very ugly:&lt;p&gt;&lt;i&gt;the 10-kg drone suffered an uncontrolled crash “in a wooded area of   Zurich’s university quarter only 50 yards away from a group of playing kindergarten children.”&lt;/i&gt;&lt;p&gt;One of the things that few people are aware about is quadrotor MTBF is very low relative to other common vehicles. For many drones, the expectation for failure dramatically increases just after 100-200 hours of operation[1]. Figuring out points of failures, building systematic fault trees and increasing MTBF by order of magnitude or two would be big part of the drone delivery projects.&lt;p&gt;[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;catsr.vse.gmu.edu&amp;#x2F;SYST490&amp;#x2F;490_2014_SPDAV&amp;#x2F;DST-NSPDAV_USMA.pdf&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;catsr.vse.gmu.edu&amp;#x2F;SYST490&amp;#x2F;490_2014_SPDAV&amp;#x2F;DST-NSPDAV_...&lt;/a&gt;</text></item></parent_chain><comment><author>rkagerer</author><text>They have parachutes installed. In the 2nd crash it deployed but the line hit a sharp part of the craft and was severed. Upgrades are being made (redundant cords and metal braiding) and the whole fleet was grounded in the meantime.</text></comment>