<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>swingbridge</author><text>A lighter engine certainly doesn&amp;#x27;t hurt, but it&amp;#x27;s really the batteries that are an issue. The other item often overlooked on the battery front is that most batteries hate the cold. Take your iPhone out on a 20F day and see how long that 100% charge lasts! (Spoiler alert, likely a few minutes).&lt;p&gt;As you go up in the atmosphere things start to get really cold. Until the weight and temperature issues with batteries can be address electrical aviation will be mostly a concept on paper.</text><parent_chain></parent_chain></comment><story><title>New Electric Motor That’s Super Light and Powerful for Electric Airplanes</title><url>https://transportevolved.com/2016/07/08/siemens-showcases-brand-new-electric-motor-thats-super-light-super-powerful-and-perfect-for-electric-airplanes/</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>kragen</author><text>You&amp;#x27;d think that since the article is about how this motor is a new record in power density (or rather specific power), it would include the specific power in the article somewhere.  You would be wrong, but it does include the information needed to calculate it.  The SP260D motor they&amp;#x27;re talking about has a specific power of 260 kW &amp;#x2F; 50 kg = 5.2 kW&amp;#x2F;kg.  It&amp;#x27;s not clear if this includes the weight of the batteries or not.&lt;p&gt;The article says the usual motor for the Walter Extra 330L is 315 horsepower, which is 234 kW.  The &amp;quot;E&amp;quot; in the model number &amp;quot;330LE&amp;quot; apparently refers to the electric version.&lt;p&gt;To contextualize, motor specific power is actually really important for heavier-than-air flight.  The reason Leonardo&amp;#x27;s helicopter designs wouldn&amp;#x27;t work is a lack of specific power in the (human) motors he had in mind, more than any aerodynamic reason.  (Sufficiently high specific powers can overcome even remarkably poor aerodynamics.)  The Wright brothers&amp;#x27; main innovations were: a workable system for steering, and a motor with sufficiently high specific power.&lt;p&gt;The bit about the motor&amp;#x27;s end shield seems to be describing topological optimization, but the description of the process is somewhat ambiguous.  It would be nice to see a picture of the end shield and maybe information about how it&amp;#x27;s made.&lt;p&gt;Maybe a less clueless, though even more information-scarce, article is &lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;www.flyingmag.com&amp;#x2F;extra-unveils-electric-330le&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.flyingmag.com&amp;#x2F;extra-unveils-electric-330le&lt;/a&gt;&lt;p&gt;Other commenters are pointing out that this won&amp;#x27;t work for long-distance flight.  The Flying article I linked above says it will actually only last either 5 minutes or 15–20 minutes (it seems to contradict itself, but maybe I just don&amp;#x27;t understand it.)  So it&amp;#x27;s adequate for aerobatics only.  But it should be better at aerobatics than the standard engine was.&lt;p&gt;Further links from other comments: 
&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=12060954&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=12060954&lt;/a&gt; &lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;www.gizmag.com&amp;#x2F;siemens-world-record-electric-motor-aircraft&amp;#x2F;37048&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.gizmag.com&amp;#x2F;siemens-world-record-electric-motor-ai...&lt;/a&gt; &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;newshour.online&amp;#x2F;2016&amp;#x2F;07&amp;#x2F;04&amp;#x2F;world-record-electric-motor-makes-first-flight&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;newshour.online&amp;#x2F;2016&amp;#x2F;07&amp;#x2F;04&amp;#x2F;world-record-electric-mot...&lt;/a&gt;</text><parent_chain></parent_chain></comment><story><title>New Electric Motor That’s Super Light and Powerful for Electric Airplanes</title><url>https://transportevolved.com/2016/07/08/siemens-showcases-brand-new-electric-motor-thats-super-light-super-powerful-and-perfect-for-electric-airplanes/</url></story>