Ok, I admit it, I've completely confused myself with the crap I was talking earlier. Can someone please tell me where I'm going wrong???. .. .I'm flying along, straight and level. Lift=weight, and thrust=drag, so according to Newton's 1st law, I'm not accelerating in any direction, which is great.. .. .Now, I add power (or thrust), and wait for everything to settle down. I'm now in a steady climb, at (approximately) the same speed as before - not accelerating in any direction.. .. .According to Newton, since I'm still not accelerating, lift=weight and thrust=drag (at least approximately - this won't be exact because the lift, thrust and drag will be at a small angle). But I know that thrust has increased (I increased it!), so that means that drag must have been increased too, right?. .. .But drag is 1/2*rho*V-squared*Coefficient-of-Drag. Rho hasn't changed. V-squared hasn't changed (very much). I haven't re-trimmed, so I'm still at the same angle-of-attack, so the coefficient of drag is the same. So it seems like the drag hasn't increased.. .. .But in this case, the forces wouldn't balance out, and I'd be accelerating.. .. .What have I got wrong here???. .. .I used to know this, but I've obviously forgotten! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> . .. .Thanks. .. .FFF. .---------