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Old May 17th 18, 04:14 PM posted to rec.aviation.soaring
Papa3[_2_]
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Default Landing with reduced airbrake

On Tuesday, May 15, 2018 at 11:47:10 PM UTC-4, Richard McLean wrote:
Thanks for that George - yes, a bit of experimentation might be a good idea.

One of our most experienced pilots says the LS8 requires an airbrake reduction to avoid excessive tail-first landings, so perhaps it's the same with this configuration DG-1000.

Cheers,

Richard

On Wednesday, 16 May 2018 11:35:57 UTC+8, George Haeh wrote:
Newer gliders with powerful air brakes will lose airspeed rapidly in the flare. Flaring too high or from an inadequate airspeed, especially with powerful air brakes full on, can end in a hard landing.

Perhaps the tailplane in the taller gear variants of the DG-1000/1 produces more lift as it rotates around the main gear to cushion the tailwheel contact.

A less tall gear does increase the possibility of a tailwheel first landing.

Another consideration is the amount of tail ballast carried.

Have you noticed if there's a difference with heavier or lighter pilots in the front seat?

It might be useful to have two experienced pilots, one to video and take notes, to do landings at various airspeeds and CGs to determine optimal landing parameters - and determine what to avoid.


I owned an LS8 for about 13 years, so figure about 450-500 takeoffs and landings. I don't remember anything special about the flare and touchdown. The POH is very clear that with airbrakes fully extended one needs to carry additional airspeed and that a slip with full airbrakes is not recommended.. That said, I never had any trouble stuffing the glider into some fairly short spaces.

I can see a scenario where the pilot is coming in right at the minimum approach speed and full divebrakes, mis-judging the roundout, and hauling back on the stick resulting in a very firm arrival. But the same applies to other gliders. I once borrowed a friends ASW-20 (original version) and demonstrated a max-performance approach with full flaps. Roundout, touchdown, and "oh sh***" all in one smooth motion :-)

P3