Stall/spin and ground reference maneuvers

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.

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.