Full run-up?

[Mayhemxpc]

Maybe I am misreading your post, but I think that you might miss the point. Of course it should be an easy guess that 3500 feet should be enough for a C172 at MGW with reasonable density altitude. That wasn't the point. The issue is being able to stop the airplane safely before you run out of runway if something isn't right. I agree that a pilot familiar with his or her aircraft should know the point at which an abort decision would have to be made without having to figure it out each time. I know without calculating that half loaded, my plane should be at Vr NLT 1000 feet down the runway. Not that I have some inherent insight, it is that I have done the calculation enough that I know the rough parameters by heart. I am constantly surprised at how many pilots don't know the abort point. What is the abort point on your 172? If someone is really familiar with the plane, they don't have to think about in feet, but in time. If not at Vr about 20 seconds after feeding the front engine in, something is wrong. Stop and figure it out.

So I ask pilots to figure that out for me on any review or instruction I give. If the pilot can give me a ball park answer that is fine. After all, we are not going to fly in test pilot conditions.

[Lrrryo]

Maybe I am misreading your post, but I think that you might miss the point. Of course it should be an easy guess that 3500 feet should be enough for a C172 at MGW with reasonable density altitude. That wasn't the point. The issue is being able to stop the airplane safely before you run out of runway if something isn't right. I agree that a pilot familiar with his or her aircraft should know the point at which an abort decision would have to be made without having to figure it out each time. I know without calculating that half loaded, my plane should be at Vr NLT 1000 feet down the runway. Not that I have some inherent insight, it is that I have done the calculation enough that I know the rough parameters by heart. I am constantly surprised at how many pilots don't know the abort point. What is the abort point on your 172? If someone is really familiar with the plane, they don't have to think about in feet, but in time. If not at Vr about 20 seconds after feeding the front engine in, something is wrong. Stop and figure it out.

So I ask pilots to figure that out for me on any review or instruction I give. If the pilot can give me a ball park answer that is fine. After all, we are not going to fly in test pilot conditions.

Chris,

Good points. One does need to have an abort point/plan in mind before taking the runway and questioning that for a review tells you if he's got that plan done.

Also, we have to accept that we "may or may not" have enough runway to stop short of the end, or continue to fly. A good deal of the time, in twins, we have an area where you just can't do either.... and if you abort, you're going off the end. That's a risk benefit we need to examine on every flight. Fortunately, in most of todays GA twins we can have a "balanced field" with about 5000 feet. I know a lot of POHs say you can do it in less, but I'd be doubtful for most of us.