S-turns on final

On Friday, February 17, 2017 at 10:42:13 AM UTC-8, John Cochrane wrote:
I think the main point against S turns is that they will not actually lose that much altitude -- unless you turn 90 degrees or more. If you are so high that full flap spoiler and slip are not going to work, then try to do S turns, but get nervous about it and don't head the nose more than 45 degrees away from the runway, you're just not going to get down that fast, and the runway will still slide along below you.

Then there is always the Marty Eiler special: Full spoiler, point the nose at the ground, go VNE to 5 feet off the deck. Even accounting for the float in ground effect, it uses up gobs of altitude.

John Cochrane.

I was running the line at Mountain Valley one day when Rich Benbrook wanted to demonstrate to a student that you could not be too high on final. I relayed to the tow pilot "2000' at the end of the runway behind you". They released, lined up with the runway, full airbrakes and PUSH.
Looked like a Space shuttle landing in a Twin Grob. Rolled casually to the start line.
But I wouldn't try that in a Nimbus 3 or even a Duo.
Jim

On Saturday, February 18, 2017 at 1:57:34 AM UTC+3, JS wrote:
On Friday, February 17, 2017 at 10:42:13 AM UTC-8, John Cochrane wrote:
I think the main point against S turns is that they will not actually lose that much altitude -- unless you turn 90 degrees or more. If you are so high that full flap spoiler and slip are not going to work, then try to do S turns, but get nervous about it and don't head the nose more than 45 degrees away from the runway, you're just not going to get down that fast, and the runway will still slide along below you.

Then there is always the Marty Eiler special: Full spoiler, point the nose at the ground, go VNE to 5 feet off the deck. Even accounting for the float in ground effect, it uses up gobs of altitude.

John Cochrane.

I was running the line at Mountain Valley one day when Rich Benbrook wanted to demonstrate to a student that you could not be too high on final. I relayed to the tow pilot "2000' at the end of the runway behind you". They released, lined up with the runway, full airbrakes and PUSH.
Looked like a Space shuttle landing in a Twin Grob. Rolled casually to the start line.
But I wouldn't try that in a Nimbus 3 or even a Duo.
Jim

At Foxton airfield (NZ) there are some very high pine trees exactly 100 metres before the boundary fence. Most people approach around the end of the trees and then make a 30 degree turn at 50 ft -- including the guys with the Pitts. I decided to try approaching over the trees one day in the DG1000. I started my final from well back at 1000 ft. When I could just see the fence over the top of the trees I opened full brakes. That wasn't enough, so I also nosed down. It turned out to need 95-100 knots to maintain the visual picture and just clear both the trees and the fence (standard farm cattle fence). I whizzed past the folks and gliders assembled at the launch point and took about 400 metres to slow down to landing speed, plus of course another 100 to stop without the wheel brake.

That was still before the official displaced threshold for landing over the trees.

A slip (with brakes) would probably have let me achieve the same descent angle at a lower speed, but I haven't had a chance to try it.