Landing with reduced airbrake

On Thursday, May 17, 2018 at 9:00:15 PM UTC+12, Jonathon May wrote:
At 06:36 17 May 2018, Bruce Hoult wrote:
On Thursday, May 17, 2018 at 1:43:09 PM UTC+12, Richard McLean wrote:
On Wednesday, 16 May 2018 22:21:48 UTC+8, Matt Herron Jr. wrote:
from my perspective, reducing airbrakes at 100' changes your glide
slop=
e and therefor aim point half way through final. So do you give up your
in=
itial aim point at 100', or do you have two aim points? Either option
seem=
s like a bad idea for students.
=20
Airbrake deployment should be a driven variable to maintain a correct
a=
pproach, not the other way around.
=20
Additionally, a shallower approach for the last 100' means you are
way
=
more susceptible to wind shear, as you don't have much "extra" glide to
rec=
over by closing the airbrakes.
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To me, it sounds like the tail strike problem is in the flair, not
the
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use of airbrakes.
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Hi Matt, yes you give up the original aim point. This isn't ideal but
bet=
ter than damaging the aircraft? The debrief can cover off the reasons.
Lots=
of bad landings are the result of not accepting that you stuffed up your
o=
riginal aiming point & concentrating on the actual landing.

I'd think if you were so high turning final that you can't get back on to
a=
standard half brake approach by, say, 100m before crossing the fence
then
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you've well and truly stuffed up the circuit. Especially in something
with
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airbrakes as powerful as a DG1000 or Grob. You definitely should never be
p=
lanning to carry full brake all the way down the approach ... that leave
no=
thing in reserve for the unexpected.

Trick one
I have not flown the DG1001 neo yet but I have quite a lot of time in the
original DG1000,you need a step to get people in,if that is the angle for
2point landing them the newer versions going to land tail wheel first .

I have done hundreds of trial flights in an early DG500 that everyone said
was "over braked" ,in fact it could be .But as all I wanted was to get the
punters down safe without a hard landing I tend to add 5kns and gently fly
it on, on the main wheel.
The trouble with that is its not the correct method to teach landing to
pupils.

As I said tricky
My advice would be to buy a K21 or Duo xl ,they fly as you would expect.

Not necessary. All you need to do is fly close to the ground and gradually slow and increase the pitch until you are in the same attitude as you would be on the ground.

Assuming you have levelled out at the correct height for your undercarriage length it all works out just the same as any other glider. Main wheel is skimming just a few inches above the ground, once the AOA gets to the point that the tail wheel touches gently you physically can't increase the pitch more, and do the main will gently drop on.

Whether the glider is actually "stalled" at that point or not is irrelevant..

If you level out a DG1000 Club at the same height as you would a standard DG1000, and then slow until it stalls, then you're going to be dropping on hard from a foot up no matter what you do. Know how it looks out the window of your glider when it's on the ground!

Less spoilers near touchdown should cause a lower sink rate and lower the chance of a bad attitude tail strike breaking something.

But doing the last half of final aiming for the end of the runway with a small spoiler setting puts you in a low energy situation. With a long runway, this could be fixed by moving the aim point down the runway and expecting the student to get there.

As far as training is concerned, I wonder if this might miss the goal of landing with the right sight picture, right touchdown attitude, in a short field, or over a tree line. That seems a lot of forced relearning later in trade for saving the trainer.

Maybe this isn't the right trainer to use first to teach landing?

On Thursday, 24 May 2018 08:50:42 UTC+8, wrote:
Less spoilers near touchdown should cause a lower sink rate and lower the chance of a bad attitude tail strike breaking something.

But doing the last half of final aiming for the end of the runway with a small spoiler setting puts you in a low energy situation. With a long runway, this could be fixed by moving the aim point down the runway and expecting the student to get there.

As far as training is concerned, I wonder if this might miss the goal of landing with the right sight picture, right touchdown attitude, in a short field, or over a tree line. That seems a lot of forced relearning later in trade for saving the trainer.

Maybe this isn't the right trainer to use first to teach landing?

We teach initial landings in the ASK21 & now the DG-1001 (nosewheel version) which has replaced the SZD-50 Puchacz. Here in Oz we teach "1/2 to 2/3 airbrake on final" .. the problems only come into play when the student mishandles the approach & overshoots, then corrects by pulling full brake & consequently over-rotating ... all I'm suggesting is that in this specific scenario we limit the amount of airbrake used to help avoid the over-rotation & instead accept the overshoot. The DG is fine otherwise, it just lands a little hot as described in the previous posts, and it has a heavy tail.