glider aerobatics

On Monday, July 31, 2017 at 7:39:26 PM UTC+3, Frank Whiteley wrote:
On Monday, July 31, 2017 at 9:47:34 AM UTC-6, 150flivver wrote:
On Monday, July 31, 2017 at 10:32:26 AM UTC-5, Burt Compton - Marfa Gliders, west Texas wrote:
On Sunday, July 30, 2017 at 7:06:35 PM UTC-5, 150flivver wrote:

So tell me why you bothered to have the ASK certificated Acrobatic if it were true that any maneuver "approved" in the POH would be legal regardless of what the Airworthiness Certificate says. I've read all the regulations you cited and nothing jumps out as an answer to my original question..

I was not trying to answer to your original question. I just wanted to clarify the FAA definition in FAR 91.303 and 91.307.

The certification of my ASK-21 as aerobatic was no bother at all. I asked the Schleicher factory to certify it aerobatic in Germany. They simply added the static line red rings, crotch strap (only for inverted flight according the the British) and G-Meters front and back.

G-Meters marked with the red lines for positive and negative (for that glider) are essential for safe aerobatics! Consider adding (calibrated) G-Meters to any glider in which you will fly aerobatics.

Schedule instruction from a proficient glider acro instructor such as at Arizona Soaring, south of Phoenix.

An airplane is not always the best method to learn glider acro as it can use full power to round the loop at the top and mitigate "dish-out" from inverted flight.

The Germans take glider acro very seriously requiring a separate pilot license for acro after a structured course of ground and flight instruction.

Penny for my thoughts? There's my two cents!

Don't disagree with anything you or JJ have said. Neither of you have answered my question and that's okay if you don't know the answer. My question is: Is it legal to do loops in a Standard (not Acro) certificated glider? Not is it smart or what the difference is between two gliders, one with an Acro cert and one without. I'm asking whether a POH approved maneuver that would be Acrobatic in Airplane and require a Acrobatic Airworthiness certification, is legal in a non-acrobatic certificated glider.

Punching through the flight manuals for a Twin Astir and Twin II, simple aerobatics are spelled out as loops, spins, and stall turns. In the UK, this was called semi-aerobatic and stall turns were called chandelles. The flight manuals also describe what to do in the event a failed stall turn results in a tail slide.

There is no way in the world that a chandelle can result in a tail slide! If by "stall turn" you mean pointing the nose straight up and at speed X stomping on one rubber then that is not a chandelle. A chandelle maintains coordinated flight at all times. It is rather like the start of a barrel roll, from lower speed, followed by the end of a barrel roll, but joined by a low speed low but positive G bit in the middle with the fuselage horizontal and 90 degrees or a bit more of bank.

It's pretty much the same as the maneuver that ag pilots do every minute or two, all day, turning around from low level at the end of the field and going back the other way with a small sideways offset.