1-26E Aerobatics

Does anyone know if it is safe, assuming you are properly trained in aerobatics,
to perform loops, rolls and inverted flying in a 1-26E?
Glider is rated at +5.3 -3.3 Gs

Schweizer Aircraft Service Bulletin SA-003 is clear. "Schweizer Aircraft Corporation DOES NOT APPROVE OR RECOMMEND that aerobatics of any kind be performed in any of the Schweizer sailplane models affected by this Service Bulletin..."

http://klsoaring.com/index.php/downl...ervice-letters

On Sunday, September 29, 2019 at 1:45:20 PM UTC-4, wrote:
Does anyone know if it is safe, assuming you are properly trained in aerobatics,
to perform loops, rolls and inverted flying in a 1-26E?
Glider is rated at +5.3 -3.3 Gs

Loops are fine but it takes a lot of time (and altitude) to build up sufficient speed. I would not do inverted flight because you don't know what's going to come up from below the floor boards. When I did an acro course, everything in your pockets was locked away before the flight. If anything was ever dropped in the aircraft, you did not fly until it was found.

Tony

On Sunday, September 29, 2019 at 2:21:29 PM UTC-4, Tony Verhulst wrote:
On Sunday, September 29, 2019 at 1:45:20 PM UTC-4, wrote:
Does anyone know if it is safe, assuming you are properly trained in aerobatics,
to perform loops, rolls and inverted flying in a 1-26E?
Glider is rated at +5.3 -3.3 Gs

Loops are fine but it takes a lot of time (and altitude) to build up sufficient speed. I would not do inverted flight because you don't know what's going to come up from below the floor boards. When I did an acro course, everything in your pockets was locked away before the flight. If anything was ever dropped in the aircraft, you did not fly until it was found.

Tony

When I did an acro course, everything in your pockets was locked away before the flight. If anything was ever dropped in the aircraft, you did not fly until it was found.
My home-field was frequently visited by an aerobatic pilot in his Zlin aerobatic aircraft. He had a zippered bag with 'street-shoes' and a door mat in a locked compartment behind the seat. Before getting out of his plane at the parking position, he would place the door mat on the wing and - sitting on the wing - change from 'flight-shoes' to 'street-shoes'. When getting back into the cockpit, he would wipe off his street-shoes thoroughly, change back to flight shoes, shake out the door mat and place it all back into the bag.
Call it anal but his cockpit was immaculate and he was not at risk getting a hand-full of dirt in his eyes during his performances!

Uli
'AS'

On Sunday, September 29, 2019 at 9:54:38 PM UTC-4, AS wrote:

....
Call it anal but his cockpit was immaculate and he was not at risk getting a hand-full of dirt in his eyes during his performances!


At the other end of the casualness scale, one of my early introductions to glider flight was in a Blanik L-13. The instructor offered to fly a loop. What turned out to be an open end wrench clanked in the fuselage. The very next day L-13s were grounded in the USA, so maybe this was the last L-13 loop flown in the USA.

On Sunday, September 29, 2019 at 1:12:48 PM UTC-5, Tony wrote:
Schweizer Aircraft Service Bulletin SA-003 is clear. "Schweizer Aircraft Corporation DOES NOT APPROVE OR RECOMMEND that aerobatics of any kind be performed in any of the Schweizer sailplane models affected by this Service Bulletin..."

http://klsoaring.com/index.php/downl...ervice-letters

Helpful link. That's what it says, presumably "Dawn Flight" was made a decade or so before this SB and the aerobatics in the film were pre-CGI? Was there also an AD that forbade aerobatics and required it be placarded as with some other aircraft? I have a 1-35 and will not do aerobatics w/ or w/o an AD. Thanks.

Service Bulletins are not mandatory. Original 1-26 flight manual states the 1-26 is fully aerobatic. Yes 1-26s are old, and many of them have lived colorful lives. Decide for yourself, but don't put off by a nanny letter from a former manufacturer's lawyers.

Yes Dawn Flight pre-dates this Service Bulletin by about a decade. No CGI either. There is a great article in Soaring about the production of that film, and also a new version includes an interview with the Director that is pretty interesting.

On Sunday, September 29, 2019 at 12:45:20 PM UTC-5, wrote:
Does anyone know if it is safe, assuming you are properly trained in aerobatics,
to perform loops, rolls and inverted flying in a 1-26E?
Glider is rated at +5.3 -3.3 Gs

I have seen people perform loops in them and it is legally a fully aerobatic glider but the service bulleton says that you cannot but I do believe that that was due to people not being trained for how fast the glider accelerates so they would go past Vne and rip a wing off.

On Tuesday, October 1, 2019 at 11:25:27 AM UTC-4, wrote:
On Sunday, September 29, 2019 at 12:45:20 PM UTC-5, wrote:
Does anyone know if it is safe, assuming you are properly trained in aerobatics,
to perform loops, rolls and inverted flying in a 1-26E?
Glider is rated at +5.3 -3.3 Gs

I have seen people perform loops in them and it is legally a fully aerobatic glider but the service bulleton says that you cannot but I do believe that that was due to people not being trained for how fast the glider accelerates so they would go past Vne and rip a wing off.

The service bulletin was done for liability reasons.
It does fine for moderate aerobatics. Loops, rolls, inverted flight, etc all are within the capability of the ship with a properly trained pilot.
Big terminal velocity dive brakes are a benefit.
It does not snap well.
I have a video someplace of aerobatics shot from the nose back(art student school project).
FWIW
UH