WINCH AND PARACHUTE DEFINITIONS

On this page we describe both the Winch and Parachute sim objects, since currently the simulation only uses parachutes for the winch tow-cable, so they are very much linked.

 

 

The Winch

A Winch sim object will only use a limited number of parameters that the other Ground Vehicles use, specifically:

A Winch Glider Launch Vehicle

You will also need to set up a reference_points.cfg file, with numbered sections corresponding to the available drums on the winch. Each reference point you define is the point at which the winch cable for the drum will be attached.

 

Specific Animations

Currently the default winch models do not require any animations and are basically static models, meaning they don't need any specific model behaviour helpers either. This may change in future updates.

 

 

Sim.cfg

The sim.cfg file of a Winch must contain the following section and parameter:

 

[WINCH]
Parameter Description Type Required
drum_count  The number of cable drums available to the winch. A value between 1 and 3.

Integer

 Yes


 

ai.cfg

You may optionally add an ai.cfg file as part of the Winch sim object package. This file only requires the [VERSION] section and the following section and parameters:

 

[WINCH]
Parameter Description Type Required
launchHeading

The angle of the winch relative to the heading of the runway in degrees.

Default value is 0.

 Real No
parachuteTitle

The title of the SimObject to use as a parachute.

Default is "Parachute".

 String No

 

Note on SimVars

There are no specific "winch only" SimVars, however you can use the following SimVars to get information about the winch object, where an index of 0 and 1 are for the main engine, and the indices 2, 3, and 4 correspond to drums 1, 2, and 3 (depending on how many the winch has, as set up in the sim.cfg file):

 

Note that even though you have access to an engine using indices 0 and 1 in the above SimVars, those indices currently mean nothing as the winch SimObject currently does not move. This may change in a future update.

 

The Parachute

Once a glider has been made airborne, they will drop the winch cable. This cable needs a parachute on the end so that it falls more slowly and safely to the ground, and as such you will need to define a parachute sim object as part of the winch package.

A Winch Glider Launch Vehicle

 

Specific Animations

The parachute model should be designed with 2 animations which will be used to cover the five available "states" of the parachute. These are as follows:

  • State 1 - The parachute is closed
  • State 2 - The parachute animates from the closed position to the open position
  • State 3 - The parachute is in the open position, falling to the ground
  • State 4 - The parachute animates from the open position to the "flat on the ground" position, as it hits the ground
  • state 5 - The parachute is on the ground

 

The animation itself would be controlled by the contents of the animations.xml file, which would be placed in the same location as the sim.cfg file for the parachute. You can find an example of the contents of this file here:

 

sim.cfg

The sim.cfg file for a parachute sim object only requires a limited number of sections and parameters:

  • [VERSION]
  • [fltsim.N] - title, model, texture, ui_manufacturer
    NOTE: The title parameter is what will be used in the winch object as the parachuteTitle.
  • [General] - category("Parachute")

 

Note on SimVars

The parachute som object has two SimVars of note that can be accessed and used:

  • PARACHUTE OPEN: This SimVar will be false until the simulation sets it to true and can be used to control the transition from the closed state to the open animation state.
  • SIM ON GROUND: This SimVar is used to determine when the parachute has hit the ground. When true, the parachute is on the ground and so it can be used to trigger the animation between the open and flat on the ground states.

You can see an example of these SimVars being used for parachute animations here: Parachute Animation