<story><title>The Celera 500L aircraft may fly soon</title><url>https://www.thedrive.com/the-war-zone/28409/the-mysterious-and-potentially-revolutionary-celera-500l-aircraft-may-fly-soon</url></story><parent_chain><item><author>inamberclad</author><text>A few things off the top of my head that look odd:&lt;p&gt;- Who is going to want to take the time to climb to 65,000 feet in this? People going transatlantic? They&amp;#x27;ll probably still take a Gulfstream.&lt;p&gt;- Does it still get reasonable range economy at lower altitudes and true airspeeds?&lt;p&gt;- Nobody will be able to see the runway over the nose on landing.&lt;p&gt;- That door doesn&amp;#x27;t look like it&amp;#x27;ll hold up to pressurization.&lt;p&gt;- The landing gear looks very light.&lt;p&gt;- The engine is going to have very tight thermal and mechanical constraints based on its position in the rear of the fuselage.&lt;p&gt;- I&amp;#x27;m assuming it&amp;#x27;s a turbine engine in here? Trying to turbocharge something enough to get to 65,000 feet is going to be awful and very maintenance intensive.&lt;p&gt;- Update: Nope, at least one V-12 with multiple turbochargers. If there is more than one engine the complex gearbox to drive the propeller will be difficult to get approved. See the Learfan aircraft [0].&lt;p&gt;- The propeller is out on a long shaft, may cause issues.&lt;p&gt;- The propeller is a pusher configuration, which isn&amp;#x27;t inherently bad, but causes efficiency losses from turbulent air coming off the fuselage.&lt;p&gt;- Pusher configurations - especially pusher turboprops like the Piaggio Avanti are noisy.&lt;p&gt;- Update: It&amp;#x27;s a piston engine. May not be as noisy because it appears that the exhaust is farther upstream than usual. However, cooling everything will be difficult.&lt;p&gt;- High altitude flight introduces the possibility of coffin corners in the envelope and very little room between overspeed and stall.&lt;p&gt;- That big engine (for high altitude flight) will reduce room in the cabin considerably.&lt;p&gt;- Everybody and their mother will probably have a tail strike.&lt;p&gt;Source: pilot and an aerospace engineering degree.&lt;p&gt;[0]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;LearAvia_Lear_Fan&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;LearAvia_Lear_Fan&lt;/a&gt;</text></item></parent_chain><comment><author>bayesian_horse</author><text>The gulf stream would be less efficient, require more passengers and may not be able to land at as many airports.&lt;p&gt;I think they aim for some kind of long-range air taxi. Small groups which want to travel a long distance from A to B but a very short distance to and from A and B&amp;#x27;s respective airports. Business trips, most likely.&lt;p&gt;And probably the plane is no slouch at medium or even short range if it is operated by a non-airline company. Just not &amp;quot;ridiculously efficient&amp;quot;.</text></comment>
<story><title>The Celera 500L aircraft may fly soon</title><url>https://www.thedrive.com/the-war-zone/28409/the-mysterious-and-potentially-revolutionary-celera-500l-aircraft-may-fly-soon</url></story><parent_chain><item><author>inamberclad</author><text>A few things off the top of my head that look odd:&lt;p&gt;- Who is going to want to take the time to climb to 65,000 feet in this? People going transatlantic? They&amp;#x27;ll probably still take a Gulfstream.&lt;p&gt;- Does it still get reasonable range economy at lower altitudes and true airspeeds?&lt;p&gt;- Nobody will be able to see the runway over the nose on landing.&lt;p&gt;- That door doesn&amp;#x27;t look like it&amp;#x27;ll hold up to pressurization.&lt;p&gt;- The landing gear looks very light.&lt;p&gt;- The engine is going to have very tight thermal and mechanical constraints based on its position in the rear of the fuselage.&lt;p&gt;- I&amp;#x27;m assuming it&amp;#x27;s a turbine engine in here? Trying to turbocharge something enough to get to 65,000 feet is going to be awful and very maintenance intensive.&lt;p&gt;- Update: Nope, at least one V-12 with multiple turbochargers. If there is more than one engine the complex gearbox to drive the propeller will be difficult to get approved. See the Learfan aircraft [0].&lt;p&gt;- The propeller is out on a long shaft, may cause issues.&lt;p&gt;- The propeller is a pusher configuration, which isn&amp;#x27;t inherently bad, but causes efficiency losses from turbulent air coming off the fuselage.&lt;p&gt;- Pusher configurations - especially pusher turboprops like the Piaggio Avanti are noisy.&lt;p&gt;- Update: It&amp;#x27;s a piston engine. May not be as noisy because it appears that the exhaust is farther upstream than usual. However, cooling everything will be difficult.&lt;p&gt;- High altitude flight introduces the possibility of coffin corners in the envelope and very little room between overspeed and stall.&lt;p&gt;- That big engine (for high altitude flight) will reduce room in the cabin considerably.&lt;p&gt;- Everybody and their mother will probably have a tail strike.&lt;p&gt;Source: pilot and an aerospace engineering degree.&lt;p&gt;[0]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;LearAvia_Lear_Fan&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;LearAvia_Lear_Fan&lt;/a&gt;</text></item></parent_chain><comment><author>pauljurczak</author><text>&amp;gt; The propeller is a pusher configuration, which isn&amp;#x27;t inherently bad, but causes efficiency losses from turbulent air coming off the fuselage.&lt;p&gt;Teardrop shape greatly reduces turbulent flow behind the fuselage compared to the mainstream tube shape.</text></comment>