Issue link: https://iconnect007.uberflip.com/i/1228683
66 SMT007 MAGAZINE I APRIL 2020 Rutan: I thought it was a pretty airplane, and I did some calculations while I was in college that showed that that airplane would proba- bly have natural stall limiting. It had to be sta- ble. It had to have a higher wing loading on the front wing than the back, which means it's easy to design it so that it stalls first. If it stalls first, it won't go to a higher angle. It will limit itself. I thought that could solve a large per- centage of the accidents that happen in general aviation. Trying to get back to the airport, you turn back, you turn too tight, you land upside down, and you kill everybody. I was focused on natural stall limiting. I even did it on an attack airplane that had a 25-mil- limeter Gatling gun—the ARES. It was a better plane because of natural stall limiting. You can yank full stick on it, and it will make a very tight turn; you don't have to worry about it departing. I thought it was important because of the stability and control. At one point, I was chief flight test engineer on the F-4 Phantom— an airplane that had 61 accidents due to loss of control. Sixty-one airplanes without bullet holes in them are smoking wreckage on the ground, and it's based on the fact that if you pulled too much angle of attack, you're likely to begin to spin. One of those spin modes is not recoverable in the flight mode. My experience of flight testing the F-4 made me a big fan of trying to do stall limiting in the very big VariViggen. I named it after the Saab Viggen. I could vary the trailing edge and leading edge to change the lift at a given angle of attack, which was a feature that wasn't all that useful when I looked at all the data later; that's the origin of the name, too. A buddy of mine who worked for me and was flying in the backseat of the F-4 named it. It worked out nicely. I would do maneuvers in Oshkosh in front of hundreds of thousands of people and fly the base leg right at the numbers. There was nothing set where you turn and then fly a final approach; I pointed it right at the numbers. If I set the right speed at the right moment, I could roll it quickly 90 degrees and pull the full half- stick, and the airplane would slow down to its minimum speed. I'd touch down, and I could stop within 500 feet of the end of the runway, even though I was flying 90 degrees to the end of the runway. It was a cool maneuver, and it was safe. If I had tried that in an airplane that would stall and depart, it would have been a fatal maneuver. I was enthralled by that. Now, of course, that was a lousy performing airplane. Its aspect ratio, which is short wings, meant that it didn't have a very good range or great performance. My next task was to see if I could attain that same safety benefit of stall limiting by having a canard on a high aspect ratio air- plane. That's how the very easy research pro- totype was done. I did not market that. I was using a modified Volkswagen engine, and it failed twice. So, I said, "I'm not going to have people building home-builds and having acci- dents. I'm going to design a bigger airplane around an aircraft engine." That's why we had the ARES. I thought that the stall limiting was important on the attack airplane. Other than that, you don't see the canards that much, except for Proteus. Proteus had a canard because I was designing an airplane that would sit in a seven-mile diameter cir- cle over large cities with a big dish on it so that people on the ground with a six-inch dish pointed at the airplane would have broad- band. This was before fiber in the ground. To do that, I had to do something special so that the wings weren't in the way. The back wing goes up and then down, and the left wing is transparent. It's quartz and fiberglass. The right wing is carbon fiber. That's the only I had developed a lot of airplanes before SpaceShipOne, and I trusted my gut instead of spending hundreds of thousands of hours in engineering.