Azrael

registerCallback( 'destruct', function( context )
        if context.entity.seat and context.entity.seat:IsValid() then context.entity.seat:Remove() end
        if context.entity.headcrab and context.entity.headcrab:IsValid() then context.entity.headcrab:Remove() end
end )

local function spawnSeat( chip, support )
        if chip.seat and chip.seat:IsValid() then return end
        local seat = ents.Create( 'prop_vehicle_prisoner_pod' )
        seat:SetModel( 'models/Nova/airboat_seat.mdl' )
        seat:SetPos( chip:GetPos() + chip:GetUp() )
        seat:SetAngles( chip:GetAngles() )
        seat:Spawn( )
        constraint.Weld( chip, seat )
        if support and support:IsValid() then
                constraint.Weld( support, seat )
        end
        chip.seat = seat
end

registerFunction( 'getSeat', '', 'e', function( self, args )
        if self.entity.seat and self.entity.seat:IsValid() then return self.entity.seat end return nil
end )

registerFunction( 'spawnSeat', '', 'e', function( self, args )
        spawnSeat( self.entity )
end )

registerFunction( 'spawnSeat', 'e', 'e', function( self, args )
        local support = args[2][1]( self, args[2] )
        spawnSeat( self.entity, support )
end )

registerFunction( 'despawnSeat', '', '', function( self, args )
        if self.entity.seat and self.entity.seat:IsValid() then self.entity.seat:Remove() end
end )

registerFunction( 'ejectSeat', '', '', function( self, args )
        if !(self.entity.seat and self.entity.seat:IsValid()) then return end
        constraint.RemoveConstraints( self.entity.seat, 'Weld' )
        local phys = self.entity.seat:GetPhysicsObject()
        phys:SetVelocity( self.entity:GetUp() * 100000 )
end )