Eagle1
2nd Feb 2006, 19:33
After having placed a question on this forum on the subject of Va (many thanks for the answers), I have two more. It seems that there are more than enough people around who are willing to give good questions a thought (much appreciated!), so I'll throw in two more.
- Firstly: when flying a glider (which I do), how come that during a turn the sinking speed is always more than in 'straight and level' flight? When I learned to fly, which is more than a few years ago, I was taught that 'Lift gets a horizontal component, making the aircraft turn, so the vertical lift-component becomes less and the airplane starts to sink more'. Sounded good, in those days, but now I'm supposed to teach this to newcomers in a while, and I'm beginning to doubt: why can't we just pull the stick enough to create sufficient lift, so we'll maintain the original sink, and not go down faster? What's the limiting factor? Stallspeed? Alpha? Increasing induced drag, reducing speed, so we'll have to pull more on the stick, which means a higher AoA, which again means more Di, which means losing speed again, etc.?
- Secondly: How come an airplane has a lower load factor (lower than one) during a constant, steady climb? That really baffles me: I know that during a climb Lift is lower, because part of it is taken over by Thrust, but still... Me, as a pilot, am taken upwards, against the force of Gravity, so I'd think the loadfactor would even be a little more (Gravity pulling me down, me going the other way). Could it be that I'm experiencing a different loadfactor than my airplane? Would this mean that, when we're going up after take-off in a Boeing, we're all weighing a little less temporarily?
Sorry for the long story, I hope Einstein doesn't have anything to do with this.
Any long or short answers much appreciated.
Eagle
- Firstly: when flying a glider (which I do), how come that during a turn the sinking speed is always more than in 'straight and level' flight? When I learned to fly, which is more than a few years ago, I was taught that 'Lift gets a horizontal component, making the aircraft turn, so the vertical lift-component becomes less and the airplane starts to sink more'. Sounded good, in those days, but now I'm supposed to teach this to newcomers in a while, and I'm beginning to doubt: why can't we just pull the stick enough to create sufficient lift, so we'll maintain the original sink, and not go down faster? What's the limiting factor? Stallspeed? Alpha? Increasing induced drag, reducing speed, so we'll have to pull more on the stick, which means a higher AoA, which again means more Di, which means losing speed again, etc.?
- Secondly: How come an airplane has a lower load factor (lower than one) during a constant, steady climb? That really baffles me: I know that during a climb Lift is lower, because part of it is taken over by Thrust, but still... Me, as a pilot, am taken upwards, against the force of Gravity, so I'd think the loadfactor would even be a little more (Gravity pulling me down, me going the other way). Could it be that I'm experiencing a different loadfactor than my airplane? Would this mean that, when we're going up after take-off in a Boeing, we're all weighing a little less temporarily?
Sorry for the long story, I hope Einstein doesn't have anything to do with this.
Any long or short answers much appreciated.
Eagle