Function process_fall_flying_activation 

pub fn process_fall_flying_activation(
    query: Query<'_, '_, (Entity, &MinecraftEntityId, &PlayerAbilities, Option<&LastSentInput>, &Jumping, &Inventory, &Physics, &OnClimbable, &mut FallFlying), (With<HasClientLoaded>, With<LocalEntity>)>,
    commands: Commands<'_, '_>,
)