Debunking Glider Spoiler Turns Causing Spin Thinking

Hi Surge, which club and instructor was that? It certainly is not normal practice in SA

Piggott pointed out that the airflow over
the tailplane in a turn comes at an angle
that requires more elevator than normally
available to stall the glider.

On one of my spin checks, we found that
the Puchaz will spin out of a 45 degree
banked turn.

Exactly-- in turning flight, the flight path is curved, and therefore the relative wind (direction the airflow would come from if not disturbed by glider) is curved too-- at any given instant, the nose of the glider is moving in a different direction than the tail. In the real world there is downwash etc but the horizontal tail is still meeting the air at a different angle in a turn than it would in wings-level flight. So is the vertical fin.

For an extreme case of curvature of the relative wind in the yaw dimension, just visualize the relative wind at different points on a glider that is flat-spinning! Different parts are moving in different direction and experiencing different relative wind directions.

S

On Sunday, June 7, 2015 at 10:00:08 PM UTC-5, George Haeh wrote:
Piggott pointed out that the airflow over
the tailplane in a turn comes at an angle
that requires more elevator than normally
available to stall the glider.

On one of my spin checks, we found that
the Puchaz will spin out of a 45 degree
banked turn.

On Sunday, 7 June 2015 17:05:05 UTC+2, OG wrote:
Hi Surge, which club and instructor was that? It certainly is not normal practice in SA

Hi Oscar

It was with two very experienced instructors at MGC (Orient) but I'll refrain from mentioning their names as they're not on this newsgroup to defend their point of view.