How to call for a tow plane after you are already in the Fly Now mode of the simulator

I know of the MISC. EVENT (TOW_PLANE_REQUEST). I have a WASM module that I am
able get simvar values and set up client events mapped to sim events. I have
tried to send this event but I am not successful. I am sure it is something I
am doing. I understand the criteria: Request a tow plane. The user aircraft
must be tow-able, stationary, on the ground and not already attached for this
to succeed. And this has been met. I have entered the Sim with a glider,
configured to tow and I am spawned correctly attached to a tow plan and ready
to fly. I use the TOW_RELEASE command. I am released from the plane. I send
the TOW_PLANE_REQUEST and nothing happens. Is this because I coded something
wrong? or is the event not supported? or is this sequence not supported? If
anyone can illustrate the right way to do this (any language), I would greatly
appreciate it.

Hello @rsebastian57 I just tested the feature on the DG-1001E glider with a
C172 as a tow aircraft, by editing the InputEvent SimConnect SDK sample and
sending TOW_PLANE_RELEASE and TOW_PLANE_REQUEST events and it worked as
expected. Are you sending those events from a WASM module used by your own
glider? Regards, Sylvain

Yes. I am using WASM on my own glider. The TOW_PLANE_REQUEST is not an option
in the SimConnect app in the SDK samples, but I will try to modify an existing
C++ sample event code in SDK and try that.

FYI the freeware glider AS-33 ( issues the
“tow plane request” ok from within the model XML, in that case it is linked to
some RPN code that detects a rudder waggle and checks whether the tow plane is
‘connected’, if not then issue the request. So worst case you could move your
request code to XML and trigger that e.g. by toggling a variable from the
WASM. WASM is a bit of a niche choice IMHO, as presumably you’re not porting
anything over from FSX. Is this a stand alone module? What’s the glider ?

I have successfully been able to get the TOW_PLANE_REQUEST to bring the tow
plane back and connect to my glider using WASM. Now the problem is that once I
waggle the rudder to have the tow start, the plane revs the engine and starts
moving. I get a few feet and then the tow plane shuts down the engine and
stops. This is the same for every tow plane I have tried and every glider I
have tried. If I use the winch launch mechanism, it works fine.

Hello @rsebastian57 Where are you spawning when you witness this?

I am trying a similar function in my glider. I find that I won’t be able to
take off in high grass. Or if my glider has a contact point on a front skid
lets say that is allowing the aircraft to nose down, I guess creating more
friction. There is a balance. Try taking off from pavement first to see if
that works. Edit: I suggest if you can, make a grass strip next to your runway
of choice, that way the grass is short and poses less friction. Works for me.

I am completely successful in towing my glider. ONCE. It is if I land, reset,
and request a new tow. The plane shows up. The wing runner is there. The tow
starts, but then stops as indicated. Glider has not changed between tows. I am
sure this is a bug in MSFS 2020.