Jump to content

Kalashnikov63

Members
  • Posts

    13
  • Joined

  • Last visited

Community Answers

  1. Kalashnikov63's post in Excessive P-Factor on P47 was marked as the answer   
    Part of my problem is the fact that I'm trying to operate a P-47 like a P-51, and the latter is no more difficult to liftoff than a Saratoga, which many private aviators operate today.  The P-47, on the other hand, is a different animal.  The P-51's Packard V-12 revs a bit higher, and generates quite a bit less torque than the Pratt & Whitney 2800 Double Wasp, which, when combined with the 4-bladed paddle prop used late in the war, is both a torque, and p-factor nightmare.  I watched the Corsair takeoff repeatedly (I assumed it was running a late-war 4-bladed prop), and I could, without exaggeration, literally detect the points at which the entire airframe was being twisted about its longitudinal axis, after control surface errors threw the plane out of dynamic equilibrium, by the massive torque of the Double Wasp.  Keep in mind that torque and horsepower are related by the value 5250, so if a Double Wasp is making 2,100 hp at 2,700 RPM (about 4,100 ft/lb. torque) imagine how much more torque it must be generating than the Packard V-12 in the P-51, which only generates 1,700 HP (MAX) at 3,000 - 3,100 RPM (only 2880 ft/lb. torque)
    Last but not least, a BIG thank you to those who threw their hats into the "Controller" ring.  My X-52 must be 30 years old by now (yes, I'm an old timer!), and when I took a look at the axis behavior, the "Y" (pitch) axis would spontaneously, without warning, jump its values up and down.  It's often too quick to notice, but I'm willing to concede that if I'm approaching a critical AoA, and it glitches that way, it could easily disrupt the dynamics of the model, and cause the code to "think" that I had quickly pulled back on the stick, and precipitate p-factor hell - but not so much on the P-51.
     
    Thanks to all for the conversation!   😀
     
×
×
  • Create New...