Wheel brake effectiveness standards

On Saturday, October 17, 2020 at 5:51:58 PM UTC-4, Martin Gregorie wrote:
On Sat, 17 Oct 2020 13:51:16 -0700, AS wrote:

Hi Kenn - not sure I understand! In the B4 and any other glider I am
familiar with, the spoiler handle is on the left side and there is no
brake actuation via the spoiler handle - not by pulling it back fully or
by a brake lever on that handle. The right hand is on the stick and the
brake handle is mounted on it to the front of it. It does not take a lot
of dexterity of the hand to wrap two or three fingers around the brake
handle and squeeze it while continuing to hold the stick back.

Most of the single seaters I've flown (Libelle, Discus 1, Pegase 90 use
that arrangement, but I flown a few fairly common types that don't:

- ASK-21: the wheel-brake is applied by pulling the air-brake handle back
past the (spring-loaded) fully air-brake stop. Both brakes work well.

- SZD Puchacz: the air-brake handle is too far back which makes it
awkward enough that some people can't get full air-brake, not that this
is a problem because the air-brakes and HUGE, fully speed-limiting and
tend to stay where you leave them. Just as well because the wheel brake
is a black knob on the left just in front of the air-brake handle's
forward position. Both brakes work well.

- the SZD Junior originally has a bicycle handbrake type wheel-brake but
it was on the air-brake handle rather than the stick, where its pivot
severely weakened the air-brake control assembly. There was an AD to fix
this by deleting the bicycle handbrake control and connecting the wheel
brake to the air-brake handle so that pulling against the stop with the
brakes fully out applies the wheel-brake.

- IIRC the Grop G.103 Acro also has the wheel-brake connected to the
air-brake lever but its been a long time since I flew a G.103 and our
club no longer has one so I can't check.

And lets not forget the much older gliders with nose skids (Slingsby
T.21, Schweitzer 2-33, unmodified ASK-13s*) which don't have a wheel-
brake: you just put the nose skid on the ground and maybe push on the
stick a bit to make them stop quicker.

* most of the K-13s I've flown were retro-fitted with a nose-wheel and
wheel-brake.


--
Martin | martin at
Gregorie | gregorie dot org

IIRC the Grop G.103 Acro also has the wheel-brake connected to the
air-brake lever but its been a long time since I flew a G.103 and our
club no longer has one so I can't check.
You are correct, Martin! That's how our G103 - III-Acro os set up.
To add to the list of strange brake systems: the Blechnik L13 has a lever on the floor-board next to the seat. The brake itself worked well; probably due to the great leverage one has by pulling up on a handle.

Uli
'AS'