
July 28th 14, 07:51 PM
posted to rec.aviation.soaring
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Low energy (full stall) landings: are they safe?
Eric always has something sensible to say! I always read his posts and
agree 99% of the time.
JMF
an old, no longer bold pilot.
At 04:03 28 July 2014, Eric Greenwell wrote:
wrote, On 7/27/2014 3:29 PM:
On Thursday, July 6, 2000 3:00:00 AM UTC-4, Tom Serkowski wrote:
If one has nearly full spoiler prior to the flare, a 'wheel'
landing is almost impossible and is a perfect setup for a very nice
minimum energy landing.
Think about the situation of being in a tail high attitude, well
above stall, main wheel a few inches above the ground. The CG is
behind the wheel, so a sudden down gust pushes the glider down.
When the main wheel hits the ground, the tail is still high and so
the AOA increases and next thing you know, you're at 10 feet with
no airspeed. In a 'nose dragger' such as ASK-21, DG-505, etc, the
nose wheel will hit hard, maybe colapse, but will also cause the
nose to bounce up and again you're left wit altitude and no
airspeed.
I fly as steep an approach as I can, then use nearly full spoiler
at touchdown and have never had a problem in over 2000 hours and 27
years of soaring in the southwestern USA.
Most of the landing incidents in both gliders and airplanes that
I've seen have been due to too much energy at touchdown - not too
little. I don't count landing short of the runway as too little
energy, that's a poor approach.
Just my $0.02 worth.
--
ASW-20b http://www.Serkowski.com
Ajajaj! reading these posts it seems like there is more
misconceptions about landings as there is stars in the sky. I learned
to fly in Croatia on an L-13. Full flaps and you bleed out airspeed
right above the runway until you do not hear the wind noise and at
that point you are on the ground. You start your flare with full
spoilers and then you smoothly retract them as you keep the glider
right above the ground. Once on the ground, you either pop them out
again to shorten your rollout or keep them in to go a little farther.
How you land depends on the glider type. I miss flaps on L23 and that
does not allow me to slow down as much as L13 and rollout is longer.
Anyhow, the wing is STALLED if you do it right and there is no
returning back in the air at that point. Spoilers out make it
impossible to become airborne again after a full stall landing. I
landed L23 in some pretty stiff crosswinds and never had control
issues. Jantar Standard is a special case. It was designed to be
landed on tailwheel as the angle of incidence of the wing is very
low. As long as one does not go crazy on lifting the nose too high
and slamming the main wheel down from 4 ft. Every type has it's own
special flavor for landings but if you land wheel or both at the
minimum speed possible for that attitude and get the spoilers out,
you are staying down. Touch down too fast in anything and you just
became a test pilot. Add a sudden gust to the tire bounce and leave
your spoilers in and you are in for some interesting times. Proper
training and repetition of things forgotten is the key. FAA cutting
out spins and engine failures in takeoff is a testimony to what is
wrong with flight training not what is better. Not training pilots
for something that WILL happen to them sooner or later is insane.
Making a 3deg approach on a VFR flight is another insanity I will
never get. You are dragging on the engine power for 3-5 miles and if
it quits, you will never make the runway. You could have come high
within gliding distance and practice gliding to a landing every time
to prepare for that day when the engine does quit. I had five of
those and not a scratch on the planes. Proof is in the pudding.
Where do these old posts come from, like Serkowski's? Are they doomed to
roam the Internet until someone responds to them, like a frog prince,
whose spell can only be broken by a kiss from a young maiden?
You'll be interested to know Tom Serkowski is still flying gliders
successfully, 14 years after the post you to which you responded. I
don't know if he has the same opinions about full stall landings,
however.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl
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