On Tue, 25 Feb 2020 07:36:48 -0800, AS wrote:

On Tuesday, February 25, 2020 at 5:51:33 AM UTC-5, Martin Gregorie
wrote:
On Mon, 24 Feb 2020 22:29:32 -0800, John Foster wrote:

On Monday, February 24, 2020 at 10:54:56 PM UTC-7, Jim S wrote:
Thanks much!

Why don't we do more winch launching here in the US?

My guess would be two factors:

1) the number of people on the ground at a typical US club on a flying
day

2) if you're sharing the airfield with powered aircraft, the power
pilots
don't tend to like winch operations.

As a subsidiary point, the runways at the US clubs I've visited are
narrower than is typical here. Go he 52°11'10.74"N 0° 6'40.44"W on
Google Earth to see what our airfield looks like.

My club in the UK does a lot of winch launching and on normal flying
days, this requires at a minimum a dedicated winch driver and a launch
marshal. The LM controls the launch and may run the glider wing as
well: you DO NOT ever start a winch launch with the glider wing on the
ground. In addition we normally have an assistant for the LM, who
drives the Hilux we use for cable retrieval as well as hooking cables
on gliders, helping to manage the launch log and driving golf buggies
to retrieve landed gliders etc. On a good summer day, around 100
aircraft movements is not uncommon.

Our main run is 4600ft long and 475 feet wide, so with the cables laid
along one side, and the winch launch point 600-700 feet from the runway
threshold we have plenty of space behind the launch point for gliders
to land and the runway is wide enough for us to have an aero tow launch
queue on the opposite side of the runway. We use radio comms between
the launch points and also between launch point and with the winch,
golf buggies and Hiluxes in case you're wondering.

During weekend flying we roster a winch driver, a Launch Marshal and a
LM assistant. We used to have a few extra people at the launchpoint, so
help with retrieving landed gliders, moving the launch queue, etc
wasn't an issue, but since we moved to using a booking system, the
number of spare bods at the launch point have dropped a lot, and so
rostering an assistant for the LM has become a requirement if we are to
maintain a reasonable launch rate.

We have a two drum winch, so only need to get cables every two
launches. but with just the winch driver and an LM, the launch rate
isn't all that high. However, with a couple of LM assistants and a
dedicated cable truck driver, its possible to maintain rate of 20
launches an hour provided those in the launch queue get on with things
and don't mess about.


--
Martin | martin at Gregorie | gregorie dot org


2) if you're sharing the airfield with powered aircraft, the power
pilots
don't tend to like winch operations.

Martin,

this is mainly based on the element of the unknown! We operate off of a
country airport with a lot of mixed traffic - everything from large
buizz-jets down to motorized parachutes. The solution is a solid
operations plan and communication, communication, communication! We will
announce every launch just as any other aircraft taking off.
The announcement includes a warning to approaching traffic not to do a
mid-field crossing below X,XXXft (typically the anticipated release
altitude +500ft)
The winch monitors the radio for approaching traffic and contacts them
to find out, how long it will take for them to be overhead. A Lear Jet
will cover the '10 miles out' faster than than a Piper J3. We will then
either launch or hold the launch to avoid any conflicts.
We offer winch launches to the local power pilots to show them what it
looks like from our perspective.
We actively participate in a city-sponsored youth program introducing
youngsters to aviation and the glider rides launched on the winch are
the most favorite thing with the participants.

So, the bottom line is that it is possible to operate a winch on a busy
airport if one so desires.

Hi Uli,

Your system sounds very sensible and, in practice probably isn't unlike
our operation. On our field everybody calls downwind on our ground
frequency. Launch co-ordination is done by the winch LM - if a powered
aircraft has its engine running the winch waits for it to launch and on
landing its the LM's responsibility to spot incoming and, again, hold a
winch launch if landing plane is about to turn base, is on base or is on
finals.

When I said that a shared airfield might be a problem, I was thinking of
operating on a public field with a relatively large proportion of
visiting pilots who may not understand how to co-ordinate with a parallel
winch operation and its cable truck etc.


--
Martin | martin at
Gregorie | gregorie dot org