Glide ratio with full brakes and side slip
On Friday, April 29, 2016 at 11:20:42 PM UTC+12, Per Carlin wrote:
To be certified has the ratio with full airbrakes to be less than 1:7.
At normal approach speed.
Many gliders will do 1:2 or even 1:1 at max airbrake speed (and some few 1:0). However it will then take 500 meters to slow down, so you're better off using a slip at reasonable speed unless the steep dive with brakes will bring you down to a normal approach angle well before the threshold.
When I was doing my cross-country rating in a Std Libelle it was at an away airstrip with a 10 feet high windbreak hedge at the start of the field. After a local soaring flight and standard landing the instructors said "Good. Now go and do another, but this time turn final at the same place but at 1000 ft instead of 300 ft and see if you can get it down". I threw in a full top rudder slip during the turn to final and held it in until about 100m before the fence. And landed shorter then the previous approach.
The Janus also slips scarily well, the Twin Astir not so much, and the DG1000 somewhere in between.
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