X-56 -- cool video

[Tim Wescott]

Dunno how long the plane's been out, but if you're worried about flutter:

[Steve Helmick]

Oh, Tim...the narrator said 2005 was when the program was started. Surely, they'd get that sort of thing built and in the air in a few years, right?

The "shield" at the end was that of Edwards AFB, in the Mojave Desert. Haven't been there since October, and didn't see that one then, but we were treated to a tour of the NASA Model Shop by their Albion Bowers on a proposed Mars Lander, a flying wing with sweep, interesting airfoils, no fins, and major washOUT in the wingtips. It's referred to as the Prandtl-D project. Prandtl was, IIRC, a WWII German aero guy working on flying wings. The story was interesting, because Prandtl was working independently from others, such as Horton.

The CG was shockingly far aft, but I didn't get a number on that. However, about 10 of their shop guys were standing around with the 4 of us (brother Hugh, Bertha Ryan, myself and my wife), and I sort of whispered out the side of my mouth and asked the guy next to me "So, what's your AMA number?"  It was a L followed by 3 digits, if i recall correctly. Mine being 4 digits didn't raise an eyebrow. But a bunch of their other guys chimed in with their AMA numbers.

And no, Edwards is NOT open to the public, and we only got in with my brother's ID and vouching for us. That only got us on base. The only reason we got into the NASA lab was because we'd brought one of NASA's historic figures with us, 90 year old Bertha Ryan, who'd been a major figure in the "Lifting Body" program (pre-Shuttle). She is still quite sharp, fairly spry, no doubt due to clean living and staying single. This project is not sekrit, and videos of towed manned flights can be found on You-Tube here:


The guy on the left in the opening interview, wearing the grey jacket and grey shirt was introduced to us as the "Chief Scientist" (Albion Bowers), who met us out at the street with the NASA PR person, plus a couple of AE interns and took us into the shop. I recognized the faces of some of these guys in the video. I think the younger guy with the dark beard was the fellow I asked about his AMA number. The Asian guy seemed shy, disinterested, or very busy, and kept working on whatever it was he was doing. There are other videos on You-Tube, including at least one about the towed (pickup truck) test flight. Anyway, it's past my bedtime.    Steve 

PS: I asked Mr. Albion Bowers if he was familiar with Boeing's Pete Bowers, designer of several homebuilt airplanes. He replied that he'd met Pete, and he said they discussed possible family connection, but they didn't find any relationship. I fixed the html code for the link to work, and a few other things that were botched, probably due to late night hallucinations...




 

[Tim Wescott]

Oh, Tim...the narrator said 2005 was when the program was started. Surely, they'd get that sort of thing built and in the air in a few years, right?

I watch those with the sound off.  If you were going to put something like that into production with people inside you'd have to have a bazillion layers of redundancy -- "Oh yes, Mr. FAA certifying person, if the control system on this thing fails you don't just have an airplane that won't fly -- it'll rip itself apart in mid air.  Now could you please sign your name onto this publicly-available document saying that we can sell it to the public?"

[Brett Buck]

I watch those with the sound off.  If you were going to put something like that into production with people inside you'd have to have a bazillion layers of redundancy -- "Oh yes, Mr. FAA certifying person, if the control system on this thing fails you don't just have an airplane that won't fly -- it'll rip itself apart in mid air.  Now could you please sign your name onto this publicly-available document saying that we can sell it to the public?"

     Oy vey!  Of course, you don't make it aeroelastically unstable without the system operating. You replace the margin you build into it with structure and replace it with margin you artificially induce using the active damping.Then, you operationally prohibit airspeed and load factor combinations in the regions of low margin when the system fails.  Just like the reduced aerodynamic stability built into just about every airliner currently made.

     Brett

[Tim Wescott]

     Oy vey!  Of course, you don't make it aeroelastically unstable without the system operating. You replace the margin you build into it with structure and replace it with margin you artificially induce using the active damping.Then, you operationally prohibit airspeed and load factor combinations in the regions of low margin when the system fails.  Just like the reduced aerodynamic stability built into just about every airliner currently made.

     Brett

Well, yes, but then you need to make sure there's a way to slow down quickly if the system does fail -- they were showing the thing going unstable at 95 knots, and flying safely at 150 with the control system on.  I suspect that if you clicked off the active damping at 150 knots there wouldn't be time for a pilot to slow it down.

With enough redundancy, and good enough built-in-test to warn the pilot of the redundant systems failing -- yes, OK.  But Boeing or whoever is still going to have to design a plane around it (unless they already have, and it just isn't heavily hyped).

[Serge_Krauss]

Sorry! I just watched the rest of Steve's video and see how utterly redundant my post was, in light of what is shown. So I'm not gonna leave the distraction. Al  Bowers is a great guy and, I think, is the chief scientist there. Ludwig Prandtl is seen by many as the "father of modern aeronautics" That's about all that's left to say after you watch that second video.