Stall/spin and ground reference maneuvers

In my very short 8 years of glider only flight I've witnessed 4 pattern mishaps (no fatalities, fortunately). Two happened because the pilots wouldn't truncate their patterns even though they could see that they were way too low, one happened because an instructor pulled the release too low, and the last happened because I believed my altimeter when it said I was too high (I'd set it wrong and wasn't fully versed in TLAR). Fortunately I didn't damage either myself or the glider, but the incipient low altitude stall I experienced that day is something I'll never forget.

Is it possible to "become immune" from making mistakes in the pattern. I don't think so. All you can do is to give your full attention to flying the airplane properly. Prioritize tasks for different phases of the pattern and try your very best to execute them perfectly.

-John, Q3

On Tuesday, March 4, 2014 12:22:39 PM UTC-5, Bob Whelan wrote:
I flew gliders (only) for more than a decade before learning of "pivotal
altitude" (from an article in "Soaring" magazine as I recall). By then,
reading had also alerted me to a whole bunch of other not-then-experienced
optical illusions and "altered visual perspectives" pilots could encounter.

Meanwhile, I'd been flying successfully enough I'd not yet (or to-date) come
even vaguely close to an unexpected departure from controlled flight in the
landing pattern, despite "the usual number" of off-field landings by then..

Yet by the time I became aware of "pivotal altitude" I knew of dead pilots -
soaring and otherwise - who evidently HAD experienced unexpected departures
from controlled flight in landing patterns (mostly at airports), including
some with gobs more time than I. My conclusion? Clearly, failure to pay
attention to and control airspeed and coordination (neither being more
important than the other, IMO) - as noted above - could easily be my last mistake.

The $64,000 question is: How can a person "become immune" from making the
mistake(s) in the landing pattern that lead to NOT always being able to
effectively monitor/control airspeed & coordination in the pattern?

IMO, education is good. (Duh!) And given the complex differences among humans,
the idea of making students aware of all known possible distractions (visual
and otherwise) in landing patterns is probably a good instructional thing, and
- clearly - conveying in practical terms the "look and feel" of pivotal
altitude cannot be done in a sailplane. So if you're one of the lucky ones who
can always monitor and effectively control airspeed and coordination in your
landing patterns, then probably no need for power-plane exposure to pivotal
= altitude. But for anyone uncertain of their capabilities...maybe it'd be a
great idea to go get some personal exposure with a power instructor you're
certain is knowledgeable of - and confident about their ability to safely
teach - the concept. For I suspect not all instructors ARE safely qualified to
expose students to the pivotal altitude concept. (I hope I'm wrong, but when
it's my life at stake, I tend to be conservative! :-) )

Bob W.

I must be at risk! As I think and do it a bit differently to most here.

In the circuit I trim for landing speed c. 50% above stall speed + c. half
the headwind speed. In still air in my 27 this is 52kts and in a gale it
could be 70 or 80kts. Fast is good unless in something like a Duo going
into a small field!

In the UK we are taught not to fly a square circuit, we lop off the
downwind corner to keep us closer to the airfield (less downwind) and keep
the landing area and reference point in view. This tends to induce a
curving base leg anyway.

I aim to get at the final turn between 300ft and higher if windy and I put
in a steeply banked final turn. The steeper the bank the harder it is to
over rudder into a spin. Probably impossible at 45 or more - Chris Rollings
would know. It is also much harder to stall requiring a lot of elevator.

From the point of starting my final turn to landing I am pretty much
focussed only on the reference point and the airspeed. Keep the airspeed
pegged and use the brake to arrive in the right place.

This close to the ground it is pretty obvious if you are slipping, which
could of course be intentional. If you are side slipping on purpose you
probably don't have enough elevator to stall.

Should I give up before I kill myself?

If this is in response to one of my posts, you missed the bit where I said "...auxiliary inputs are slipstream noise, one or two glances at the ASI..."

-John, Q3

On Tuesday, March 4, 2014 1:13:49 PM UTC-5, son_of_flubber wrote:
Why are pilots so committed to the idea that they can reliably judge airspeed by looking at the sight picture over the nose? What if the runway tilts up and it is surrounded by hills and trees?

On Tuesday, March 4, 2014 1:13:49 PM UTC-5, son_of_flubber wrote:
Why are pilots so committed to the idea that they can reliably judge airspeed by looking at the sight picture over the nose? What if the runway tilts up and it is surrounded by hills and trees? The only time that I bet my life on the sight picture is when I'm on a steep final, I'm holding the air brake at a constant setting, and I'm sure that the glide angle and the touchdown point are stable and unchanging.

It is not the sight picture itself, it is the change in the sight picture that needs to be noticed.
If you are staring at the wing tip. or the landing target, you likley aren't noticing that you pulled the nose up in the turn or were skidding. Obviously terrain affects the sight picture.
When looking at the nose, a quick eye movement allows the airspeed to be checked for confirmation.
UH

On 3/4/2014 11:23 AM, John Carlyle wrote:
Snip...
Is it possible to "become immune" from making mistakes in the pattern. I
don't think so. All you can do is to give your full attention to flying the
airplane properly. Prioritize tasks for different phases of the pattern and
try your very best to execute them perfectly.

-John, Q3

Yup!


On Tuesday, March 4, 2014 12:22:39 PM UTC-5, Bob Whelan wrote:
Snip...
The $64,000 question is: How can a person "become immune" from making
the mistake(s) in the landing pattern that lead to NOT always being able
to effectively monitor/control airspeed & coordination in the pattern?

We agree on the impossibility of "becom[ing] immune" from making mistakes in
the pattern (or anywhere else/hence my original quotes). Human perfection
isn't an option.

In addition to that assumption, another of my operating assumptions is an
assumed life-critical need for continual monitoring of "things" crucial to
continuing achievement of my intentions...in this case not departing from
controlled flight in the landing pattern.

Goal (see next paragraph) achieved by: pilot control inputs (required to
achieve goal); monitoring of flight conditions/path; corrective feedback loop
to control inputs. Continue circularly until a new goal can be set and begun
acting upon...

In every landing pattern, my unchanging Primary Goal is to land safely,
without hitting anything other than mother earth - in the intended manner and
near some specifically selected desired location - with appropriate
amount/vectors of kinetic energy. Personally, I think that ought to be the
goal of every pilot's landing patterns. :-)

However Joe Pilot achieves that goal is inextricably linked with how their
brain works, hence the potential value of these sorts of brain-engaging
discussions, in my view...

Bob W.

Very good point, Bob (how their brain works). I know that there are many ways to accomplish almost everything, but as an engineer I know that only a few are "safe" and/or "efficient" and usually only one is "elegant". What fascinates me is watching someone else solving the same problem and seeing things they come up with that I never thought of...

-John, Q3

On Tuesday, March 4, 2014 2:11:00 PM UTC-5, Bob Whelan wrote:
In every landing pattern, my unchanging Primary Goal is to land safely,
without hitting anything other than mother earth - in the intended manner and
near some specifically selected desired location - with appropriate
amount/vectors of kinetic energy. Personally, I think that ought to be the
goal of every pilot's landing patterns. :-)

However Joe Pilot achieves that goal is inextricably linked with how their
brain works, hence the potential value of these sorts of brain-engaging
discussions, in my view...

Bob W.

On Tuesday, March 4, 2014 1:30:34 PM UTC-5, John Carlyle wrote:
If this is in response to one of my posts,

Not particularly your post. Many pilots are committed to the primacy of the sight picture at turn to final.

JC wrote:
you missed the bit where I said "...AUXILIARY (ed. caps) inputs are slipstream noise, one or two glances at the ASI..."


My take is that just before entering the turn to final, slipstream noise and ASI (and yaw string) are PRIMARY reliable inputs, and that point sight picture is an unreliable input that is subject to pilot error and visual illusions.

As I got better over time at using the sight picture to estimate pattern speed, I found myself relying on it more and more. My tendency to discount and neglect the primary reliable inputs made me more dangerous.

It's not just the view, though with experience you get to recognize rates of
change, there's also sound and control feel. But I think everyone
(including myself) steals the occasional peek at the airspeed indicator as
well.


"son_of_flubber" wrote in message
...
Why are pilots so committed to the idea that they can reliably judge
airspeed by looking at the sight picture over the nose? What if the runway
tilts up and it is surrounded by hills and trees?

The only time that I bet my life on the sight picture is when I'm on a
steep final, I'm holding the air brake at a constant setting, and I'm sure
that the glide angle and the touchdown point are stable and unchanging.

On Tuesday, March 4, 2014 5:11:02 PM UTC-7, son_of_flubber wrote:
On Tuesday, March 4, 2014 1:30:34 PM UTC-5, John Carlyle wrote:

If this is in response to one of my posts,



Not particularly your post. Many pilots are committed to the primacy of the sight picture at turn to final.



JC wrote:

you missed the bit where I said "...AUXILIARY (ed. caps) inputs are slipstream noise, one or two glances at the ASI..."





My take is that just before entering the turn to final, slipstream noise and ASI (and yaw string) are PRIMARY reliable inputs, and that point sight picture is an unreliable input that is subject to pilot error and visual illusions.



As I got better over time at using the sight picture to estimate pattern speed, I found myself relying on it more and more. My tendency to discount and neglect the primary reliable inputs made me more dangerous.



At low altitude and certainly in mountainous country, the "sight picture" is unreliable. (If your destination airport is in a deep "V" valley, at which rock or tree do you point the nose?) As other posters noted, at low altitude, the apparent horizon seems high so the nose appears too low even when it right. So what does one watch? The answer is a fast repetitive scan of everything. Keep coming back to the airspeed and yaw string every few seconds to note trends but don't linger there more than a second or two.

One important action is to trim the glider so it will tend to remain at the desired pattern airspeed. Sergio's article in the February Soaring where he describes pushing the stick without effect struck me as perfect description of a mis-trimmed glider. If trimmed correctly, just relaxing pressure on the stick will cause a too-high nose to lower itself - you don't have to push.

In fact, teaching pilots to fly with a relaxed grip instead of a "death-grip" on the stick would probably in itself eliminate many stall/spin accidents. A well trimmed glider simply won't spin itself - it takes gross control inputs to make it spin which is more difficult to do with finger tip pressure.

Another very useful skill is semi-instrument flying - controlling pitch attitude with airspeed alone. (It's the airspeed part of "needle, ball airspeed" partial-panel instrument flying.) This involves watching the airspeed trend. If it's trending lower, the nose is too high and if trending higher, the nose is too low. This is something that can be learned in an airplane while doing ground reference maneuvers.

Dan,

Would you do a circling approach if you were going into a difficult strip, too? Say, a narrow cornfield surrounded by trees. I ask because the Navy pilots I know who fly gliders have reverted to the non-circling approach.

-John, Q3

On Tuesday, March 4, 2014 12:59:10 PM UTC-5, Dan Marotta wrote:
I fly my pattern just like Kirk, though a little higher and faster at the
start. I begin my descending final turn when abeam the touchdown point and
roll out on final at about 200 ft and over the numbers. I do this both in
my LAK and in the tow planes.

I did it this way in the Air Force and when I flew a King Air for
FlightSafety. The only exception was in the B-727. Gotta be gentle for the
pax.