<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>sawjet</author><text>Shape is the major determining factor for radar return, not size. From Ben Rich&amp;#x27;s Skunk Works-&lt;p&gt;&amp;gt;I really wanted a photographer around for historical purposes to capture the expression on Kelly’s big, brooding moon-shaped mug when I showed him the electromagnetic chamber results. Hopeless Diamond was exactly as Denys had predicted: a thousand times stealthier than the twelve-year-old drone. The fact that the test results matched Denys’s computer calculations was the first proof that we actually knew what in hell we were doing. Still, Kelly reacted about as graciously as a cop realizing he had collared the wrong suspect. He grudgingly flipped me the quarter and said, “Don’t spend it until you see the damned thing fly.” But then he sent for Denys Overholser and grilled the poor guy past the point of well-done on the whys and hows of stealth technology. He told me later that he was surprised to learn that with flat surfaces the amount of radar energy returning to the sender is independent of the target’s size. A small airplane, a bomber, an aircraft carrier, all with the same shape, will have identical radar cross sections. “By God, I never would have believed that,” he confessed. I had the feeling that maybe he still didn’t.</text><parent_chain><item><author>Tobba_</author><text>The idea of drone swarms doesn&amp;#x27;t go well together with aerodynamics and basic physical intuition. If you shrink an aircraft down, the aerodynamic cross-section (i.e the drag force) scales with the area (scale^2), but your engine thrust is going to drop roughly by the decrease in volume (scale^3).&lt;p&gt;So you end up losing maximum airspeed &lt;i&gt;and&lt;/i&gt; fuel efficiency (in terms of the mass you&amp;#x27;re moving) the smaller you go. Unless the drones in your swarm were really big, it doesn&amp;#x27;t work out.&lt;p&gt;Although, I imagine we&amp;#x27;ll see some smaller, unmanned jet fighters in the future (assuming someone figures out how to control something like that remotely, or autonomously). A smaller aircraft has the advantage of a smaller radar cross-section and being more difficult to hit. Doing away with the pilot cuts out a lot of weight and frees up room for a larger engine and fuel tank, offseting the downsides of the smaller size somewhat. There should be a sweet spot where that works out.</text></item><item><author>bertjk</author><text>I&amp;#x27;ve thought that drone swarms are an &amp;quot;obviously&amp;quot; good idea, but that assumed that the communications&amp;#x2F;navigation were not easily spoofed.  Then Iran captured one of the US&amp;#x27;s most advanced drone, pretty much intact.  Now I&amp;#x27;m not so sure.</text></item><item><author>Someone1234</author><text>Absolutely. And the depressing part is that SOME parts still could have been shared between the different aircraft even in a more modest proposal (e.g. warfare systems). They just decided to go that extra mile, and wind up with an aircraft that likely won&amp;#x27;t ever save money and is too complex for its own good.&lt;p&gt;I hope we&amp;#x27;re done with manned aircraft after the F-35, and it is all drone swarms from here on out.</text></item><item><author>sevensor</author><text>The biggest design problem is a failure of conception:&lt;p&gt;&amp;gt; The Pentagon sold Congress on the F-35 in part with the idea of creating a common aircraft for three services, alleging it would save money—despite the well-documented and glaring failure of the tri-service F-111 program 25 years before Congress signed off on the very same plan with the F-35 in 2001&lt;p&gt;The idea that the STOVL variant would have significant parts commonality with the others despite having a giant fan in the middle was pretty laughable right from the start.  In general, three aircraft with three very different design mission profiles were not going to be able to share much without making bad compromises.</text></item></parent_chain></comment><story><title>F-35 Program Cutting Corners to “Complete” Development</title><url>https://www.pogo.org/investigation/2018/08/f-35-program-cutting-corners-to-complete-development</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>Someone1234</author><text>&amp;gt; If you shrink an aircraft down, the aerodynamic cross-section (i.e the drag force) scales with the area (scale^2), but your engine thrust is going to drop roughly by the decrease in volume (scale^3).&lt;p&gt;Why would we shrink drones down? You read drone swarm and assumed small, but most swarm proposals are using drones of a similar size as today or even large in some cases. They&amp;#x27;re swarms because of the way they interact with one another, and overwhelm enemy defensive systems, not because they&amp;#x27;re small.</text><parent_chain><item><author>Tobba_</author><text>The idea of drone swarms doesn&amp;#x27;t go well together with aerodynamics and basic physical intuition. If you shrink an aircraft down, the aerodynamic cross-section (i.e the drag force) scales with the area (scale^2), but your engine thrust is going to drop roughly by the decrease in volume (scale^3).&lt;p&gt;So you end up losing maximum airspeed &lt;i&gt;and&lt;/i&gt; fuel efficiency (in terms of the mass you&amp;#x27;re moving) the smaller you go. Unless the drones in your swarm were really big, it doesn&amp;#x27;t work out.&lt;p&gt;Although, I imagine we&amp;#x27;ll see some smaller, unmanned jet fighters in the future (assuming someone figures out how to control something like that remotely, or autonomously). A smaller aircraft has the advantage of a smaller radar cross-section and being more difficult to hit. Doing away with the pilot cuts out a lot of weight and frees up room for a larger engine and fuel tank, offseting the downsides of the smaller size somewhat. There should be a sweet spot where that works out.</text></item><item><author>bertjk</author><text>I&amp;#x27;ve thought that drone swarms are an &amp;quot;obviously&amp;quot; good idea, but that assumed that the communications&amp;#x2F;navigation were not easily spoofed.  Then Iran captured one of the US&amp;#x27;s most advanced drone, pretty much intact.  Now I&amp;#x27;m not so sure.</text></item><item><author>Someone1234</author><text>Absolutely. And the depressing part is that SOME parts still could have been shared between the different aircraft even in a more modest proposal (e.g. warfare systems). They just decided to go that extra mile, and wind up with an aircraft that likely won&amp;#x27;t ever save money and is too complex for its own good.&lt;p&gt;I hope we&amp;#x27;re done with manned aircraft after the F-35, and it is all drone swarms from here on out.</text></item><item><author>sevensor</author><text>The biggest design problem is a failure of conception:&lt;p&gt;&amp;gt; The Pentagon sold Congress on the F-35 in part with the idea of creating a common aircraft for three services, alleging it would save money—despite the well-documented and glaring failure of the tri-service F-111 program 25 years before Congress signed off on the very same plan with the F-35 in 2001&lt;p&gt;The idea that the STOVL variant would have significant parts commonality with the others despite having a giant fan in the middle was pretty laughable right from the start.  In general, three aircraft with three very different design mission profiles were not going to be able to share much without making bad compromises.</text></item></parent_chain></comment><story><title>F-35 Program Cutting Corners to “Complete” Development</title><url>https://www.pogo.org/investigation/2018/08/f-35-program-cutting-corners-to-complete-development</url></story>