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Old June 10th 13, 04:28 AM posted to rec.aviation.soaring
BobW
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Default How to landout on a steep uphill final?

On 6/9/2013 7:33 PM, son_of_flubber wrote:

Paraphrasing wildly...

"Opinions for landing technique into an uphill field, please..."

Snip

So I want to touch down with minimum energy. My first thought is to flare
to level flight much higher than normal, say 10 feet above the ground after
the flare, pull the stick back gradually to bleed off speed until the
ground comes to meet my level flight. Careful not to stall prematurely of
course.

Or do I flare at a normal height and ride the ground effect uphill?


Them's two of the basic options, alright (though "first thought" strikes me as
decidedly bizarre when viewed from the perspective of attempting to do the
same when landing on a LEVEL field/runway)...

I (also: RFW) imagine that I might fly into the slope and touch down with more energy
than I would like and possibly do a ground loop or otherwise damage the
glider (and/or my body). The field may tilt a bit left to right.


With this option you're (IMO) zeroing in on "planning goodness"...i.e. "flying
it on w/o really attempting to flare." As for worrying about the excess
energy, you'll be astounded how rapidly a noticeable uphill WILL dissipate
excess energy in any event, short field or not. That's the voice of experience
from landing gliders on uphill western runways.

The fact that the field is tilting up steeply in front of me is going to
distort my perception...


Very definitely! Perception likely would result in your (inadvertently) being
forced to implement Option 1) or 2) if you hadn't priorly thought things
through as you're evidently doing. Why? If you accurately follow the "how to
judge flare height" procedures you've (probably) been taught (i.e. focusing
eyeballs "well out in front of the glider" to judge flare height), odds are -
going into an uphill-sloping field - you'll flare anywhere from higher than
you expect to WAY higher than you expect, since the ground beneath you is
farther away vertically than the ground at which you're gazing to judge your
roundout height. Having flared high, likely also to very quickly-in-time
follow, is "the dreaded drop in." (Whump! Bad for plane and potentially bad
for your back.) The first broken sailplane I ever saw had this happen to it. A
Phoebus, dropped in from (per the pilot) 6 feet after he "routinely flared"
into an uphill field judging height from the FAR end of the field. Broke the
plywood bulkhead to which the gear was mounted, better I suppose than breaking
the fuselage, but still expensive to fix.

...and that is the other reason that I'm inclined to
flare deliberately high. That gives me more time to see what is happening
and adjust.


I suppose that's reasonable in theory, but (IMO) practice is likely to
significantly (and negatively) differ, primarily because: 1) (commenting
generally) "higher above ground than normal" in the flared condition isn't a
good situation from which to begin an energy experiment, and 2) (commenting
specifically) more or less by definition "the flared condition" is a low
energy condition. Bottom line is you will NOT have any excess energy available
to "adjust" or otherwise "fly 'er onto the ground" once flared.

Opinions and suggestions? I'm thinking about a particular field, but I'd
kinda like to know in general how to approach this type of field because
level fields are rare in my area.


Personally, my long-standing (happily never required) mental plan for landing
in a short uphill field is to judge my roundout by bringing my focal point
MUCH closer to the touchdown target point, and attempting a flown-on touchdown
from "normal height," then depend on the hill to help dissipate the
higher-than-theoretically-ideal actual touchdown speed. If I misjudge the
actual touchdown point in the sense the field meets me "too early/before I
expect it to" then any "flying bounce's" 2nd arrival from the excess energy
will be in part mitigated by the upward sloping field in any event. Further,
in my experience "flying touchdowns" are generally gentler than "flying
energy's gone" (and you misjudged the agl height, bozo) arrivals.

It should be interesting to learn others' opinions and experiences...

Bob W.