Bill Southwell

That is Fantastic!! You are taming the beast.

Looks awesome!!

Sorry to see the test didn't go perfect but it proved your fan setup will work and you have a positive amount of lift. I think you are right that the longer nose sections are creating lift and is causing the cg to need a more forward position. You could think about it like the X-3 is a lifting body with just enough wing added to allow it to take off, well at 40% of mach one..... Bill

The X-3 is looking good Simon. The picture you posted with the prosthetic proboscis and the X-3 together gave me a thought. If you have a set of small neodymium magnets grabbing each other embedded into the face of the fuselage and the rear of the nose cone and add a short indexing feature to keep it from moving around but not enough to prevent it from easily dislodging at the hint of a side load or impact. It would not need to be more than a rounded nub with a corresponding small rounded divot to fit into. If you were to make the mating surface at an angle with it being leaned rearward at the top and forward at the bottom it would the slide up and off the model on landing or if it were to contact anything or anyone. It would slide or pop off rather than being stiff in compression on a straight on impact.

Looks great! All the best on your maiden. May Lift be with you. Best Regards, Bill

Hi Simon, You are most welcome. I worried I overdid it, but it seems like every picture had a tidbit. When I saw the picture of the instrument package and that it was said there was 1200 lbs. worth of it, the inertial coupling issue started to make sense. I agree with you on the stabilator and the trim tabs...the only way they would be of any use would be in a manual control system. The photos of the horizontal stab looks solid without any sign of tabs or actuators. Artist interpretation affects most 3 views in some way. I like the one piece stab. That must have been a sobering moment sitting in that elevator seat and knowing how long it would take to bail out. Then add the high g gyrations that seem to go with experimental flight testing....low probability of survival. The F104 really benefited from the X-3. I wonder how many engineers from the X-3 project were later involved in the Lockheed efforts. Best Regards, Bill

The lamp is the back up light....lol.

I am with you on every gram left out is lift in the bank. I mentioned the leading edge droop as a possible fixed feature. It's helpful in improving slow flight and I have used leading edge droop on several delta designs and the drooped leading edge helped flight manners all around and especially slow flight and landing. I also found a pilot's manual and found it pretty interesting. Not sure if I can upload it here or not. I'll give it a try. I'll add more pics below. Best Regards Bill

I have had some good luck with researching the X-3. I have confirmed the horizontal tail used a stabilator for pitch control. And I found something that may help in gaining a little more lift for your hand launch...the X-3 required the use of it's full span wing leading edge droop plus takeoff flaps to take off. Oh and 260 knots or 300mph of ground speed as well. I have a few close up pictures of the stabilator, wing L.E. drooped, and the flaps deployed. If you want me to post them just say the word. Best Regards Bill

I have not researched as to what type of horizontal stabilizer the X3 has but the tiny trim tabs at the stabs trailing edge in the 3-views and looking at the photos it looks like it may have had a stabilator and not a stab/elevator set up. If it is a flying stab you would have a lot more pitch power without having to worry about the two part stabilizer stalling due to larger elevator travel causing air flow separation and loss of pitch control. I apologize for my ignorance on the stab type but I did not remember it being talked about and is a forgone issue already. Best Regards, Bill

Hi Simon, The long nose does put the most fragile part of the plane in the worst spot. What If you make the nose able to break away via small magnets? That may help mitigate some mutilation from it being a belly slider. That and the fabled field of soft, long, tall grass. The CG will be critical in helping with the pitch authority. A nose heavy condition would not be helpful and would be the thing to reduce or eliminate the elevator authority. If you can balance it closer to the tail heavy ,but not beyond, limit you will gain more authority. I have had airframes that were horrible, hard to land, snap happy beasts until I tried an aft limit CG. The lack of slow speed control and snappish elevator response was gone and the former terror of an airplane became a hanger favorite. The small tail surfaces will need as much help as possible. The trick is to get close but not beyond the point of no return. Preaching to the choir I am sure. My hat is off to you. You definitely know how to pick a real challenge. Best Regards Bill, Iuka, MS

Hi Simon, I have always had a thing for X-3. I thought the X-3 looked like a huge leap in design for it's time and even for today. It was a constant sketch in my school note books along with the early jets and WWII aircraft. If engine development had been up to promises a lot of failed programs might not have. I have always wanted to build an X-3 "one day" but the issue of the fuselage's apparent overabundance of side area forward of the CG plus the tiny wing and even smaller tail volume has over the years made it seem not worth trying. But......... Your bravery and obvious skills have made me a lot more optimistic about taking a better look at the design to figure out how they got that thing to fly more than once. Looking at the issue of what amount of fuselage area ahead of the CG and the tiny tail surfaces. When looking at a 2D side view it looks like it would be a tail swapper for sure. But if you look at the X-3 in pictures and look not at the entire fuselage but break the fuse down to the shapes of the sections you can, see that the fuselage just forward of the cockpit wind screen transitions to a round cross section and tapers to a rather fine point. The circular shape can't be as strong of a destabilizing force as compared to a flatter vertical fuselage shape would be. Think of what has more drag- a flat plate or a sphere? The round nose section has to be less effective in its felt effect for reaction to yaw loads for lack of better words on my part. If you look at the fuselage sides from just aft of the air intakes and all along the engines they are more of a flat vertical surface and radiused top edge. This forward area ahead of the CG will have much stronger felt effects or reaction to yaw loads leading to possible yaw instability more so than the nose cone. The area aft of the CG goes into the positive yaw stability column. The fuselage sides from the CG aft to the exhaust exits are now a positive yaw effect. The tails vertical area starts on the top center of the fuselage at about the CG and extends back to the tail cone. The aft fuselage boom if kept as flat on it's sides as you can get away with and make the top curved shape more of a triangle with the top point slightly rounded will make it more like a long vertical strake like D model P-51's and P-47 D's received after cutting down the aft turtle decks for the bubble canopies mods. My gut says it will fly straight. A flat fuselage test glider will probably not be stable in yaw. I think that if you were to add the cross sections of a 3D accurate scale shape and glue some light foam blocks in between the cross sections. Then sand it to shape. I believe the shaped glider would work. Another idea to try, a light filament 3D printed skins sort of like the old vac formed scale model kits. Use a balsa flat keel and apply the left and right halves. Sorry for being so long winded but your build thread has me amped up. All the best with your build and flight tests. I really appreciate your sharing this cool project with us. I wonder how big the X-3 would have to be to fit the 2) 80mm fans I have in the shop. More like how long it would be. LOL! With the super light built up foam models and the modern power systems, edfs and amazing batteries make almost anything possible. Best Regards Bill, Iuka, MS

This is an awesome build! Has this project been finished and flown? Looks fantastic. Thanks, Bill