Post by Tom Goodrick on Nov 6, 2010 10:58:30 GMT -5
Here's a set of photos that illustrate a Piper J-3 spin with my revised FD files for the Cub. (If you didn't get them from my old web site, email me.) This flight was made in December '03 so I don't remember all the details. But it is similar to the spins I did in a J-3 as a kid with my CAP instructor.
The spin starts with a deep stall and then with full left rudder.
The stick is held full back after the stall and the start of the spin.
I remember the real spin as more of a manipulation of the World than a manipulation of the airplane. You bring the World up into your view and then make it go around.
The rudder is the only control that works. You hold it as long as you want to spin.
When you see the gophers running for cover, it is time to recover. To recover just center the rudder and relax the stick. Handle the stick gently during recovery. You will pick up a little speed as you straighten out. Pull firmly once you are straight.
This shows the "realism" settiings I had during this flight and still have most of the time I fly FS9.
It is a lot of fun to do this in a Cub because it behaves nicely. Airspeed and descent rate do not get out of bounds. The motion is dynamically stable in real life as it is in this sim.
I did nothing special to the Moments of Inertia to achieve this flight although I think may have tweaked them a bit. For a small, light plane like the J-3, you calculate first the correct values for the empty weight and for the geometry. Then you may have to multiply each value by some factor on the order of 1.5 to get reasonable motion - no shakes. The same factor must be used with each. As with most planes MOIZ>MOIY>MOIX.
CAUTION: If you try this with larger and faster aircraft, you will find some that do not behave well. The spin can go flat, inverted and flat, and recovery may be impossible. Not all planes should be spun.
The spin starts with a deep stall and then with full left rudder.
The stick is held full back after the stall and the start of the spin.
I remember the real spin as more of a manipulation of the World than a manipulation of the airplane. You bring the World up into your view and then make it go around.
The rudder is the only control that works. You hold it as long as you want to spin.
When you see the gophers running for cover, it is time to recover. To recover just center the rudder and relax the stick. Handle the stick gently during recovery. You will pick up a little speed as you straighten out. Pull firmly once you are straight.
This shows the "realism" settiings I had during this flight and still have most of the time I fly FS9.
It is a lot of fun to do this in a Cub because it behaves nicely. Airspeed and descent rate do not get out of bounds. The motion is dynamically stable in real life as it is in this sim.
I did nothing special to the Moments of Inertia to achieve this flight although I think may have tweaked them a bit. For a small, light plane like the J-3, you calculate first the correct values for the empty weight and for the geometry. Then you may have to multiply each value by some factor on the order of 1.5 to get reasonable motion - no shakes. The same factor must be used with each. As with most planes MOIZ>MOIY>MOIX.
CAUTION: If you try this with larger and faster aircraft, you will find some that do not behave well. The spin can go flat, inverted and flat, and recovery may be impossible. Not all planes should be spun.