By teaching the apparent brisk walk rate of closure approach, I thought I had avoided this question. With that approach, there is no need to round out and hold off.

Well I was wrong. Since I was never more than a quarter mile out nor more than a couple hundred feet up, there was no transition from stabilized 1.3 Vso approach to apparent rate. There is a transition. If you are down low spraying or pipelining, it is a transition from cruise to apparent rate.

The answer to the question for those coming down from altitude with a normal approach is to round out when the rate of closure APPEARS to speed up. This will happen inside of a quarter mile but before the fence. Now that the PTS is no more than 1.3 Vso, that will transition any pilot from stabilized approach to round out to keep slowing down to prevent the speed up of the apparent brisk walk rate of closure to touchdown on the numbers or desired touchdown spot.

I have po poed technology a bit, but the GPS now shows this proper round out point or start slowing down seriously point. Notice on CFOT's latest video how the ground speed, indicated by the GPS, begins to slow down on short final. It doesn't matter if you start low like he or I. It doesn't matter if you start high like Hotrod 180 or any standardized approach. However you start the approach, the rate of closure will appear to speed up significantly on short final. Only by not allowing this optical speed up, can any approach slow enough to touchdown slow and soft (with power almost all the way or best all the way) on the numbers.

Let me know which landing are you looking at on the video and I can post a clip here if you like.

contactflying wrote:... It doesn't matter if you start low like he or I. It doesn't matter if you start high like Hotrod 180 or any standardized approach. However you start the approach, the rate of closure will appear to speed up significantly on short final. .....

Not sure what you mean about me starting high -- starting what?
Curious how you would know how high I start anything as I've never posted a video here.
I have mentioned a nose-high low-airspeed solution to being too high (above glideslope) on approach,
not sure if that's what you're referencing or not.

contactflying wrote:By teaching the apparent brisk walk rate of closure approach, I thought I had avoided this question. With that approach, there is no need to round out and hold off.

Well I was wrong. Since I was never more than a quarter mile out nor more than a couple hundred feet up, there was no transition from stabilized 1.3 Vso approach to apparent rate. There is a transition. If you are down low spraying or pipelining, it is a transition from cruise to apparent rate.

The answer to the question for those coming down from altitude with a normal approach is to round out when the rate of closure APPEARS to speed up. This will happen inside of a quarter mile but before the fence. Now that the PTS is no more than 1.3 Vso, that will transition any pilot from stabilized approach to round out to keep slowing down to prevent the speed up of the apparent brisk walk rate of closure to touchdown on the numbers or desired touchdown spot.

I have po poed technology a bit, but the GPS now shows this proper round out point or start slowing down seriously point. Notice on CFOT's latest video how the ground speed, indicated by the GPS, begins to slow down on short final. It doesn't matter if you start low like he or I. It doesn't matter if you start high like Hotrod 180 or any standardized approach. However you start the approach, the rate of closure will appear to speed up significantly on short final. Only by not allowing this optical speed up, can any approach slow enough to touchdown slow and soft (with power almost all the way or best all the way) on the numbers.

The other observable event that occurs at that point is that the equal angles of the sides of the landing strip suddenly appear to widen at the base, i.e., the legs spread.

Cary

CFOT the second I think. When the GPS shows your ground speed.

Hotrod 180 Yes a good post in the past about full flap slow steep angle approach, over trees I think.

This one?

Yes, Shannon, that one. What was your touchdown ground speed? You were soft enough I wasn't sure. I have always taught that we could be below stall in low ground effect just before touchdown. I just never had proof.

I'm not sure on that one. It was pretty gusty that day, so hard to tell what my airspeed really was by the GPS. GPS is saying about 33 mph
when I touched down. The Champ stalls about 38 mph, I agree that speed is lower in ground effect...I'll go play with it doing some hover taxiing on a calm evening.

Thanks. That will show it accurately.

Cary,

I will take a look at the widening base of the runway edge angles. Wolfgang mentioned that in Stick and Rudder, but I haven't thought about it all these years maintaining the brisk walk rate of closure all the way down. If we don't allow the rate to increase (slow down more on short final), we don't need to round out.

Good point though on the widening base.

Jim