Airport system, AirportCaller class

package AirportPkg;

class AirportCaller extends Thread {
    // create airplanes and call the airport
    private boolean canBeCalled;
    private Airport calledAirport;

    public AirportCaller(Airport calledAirport) {
        this.calledAirport = calledAirport;
        this.canBeCalled = calledAirport.isOpen();

        this.start();
    }

    public void stopCalling() throws InterruptedException {
        this.canBeCalled = false;
        this.join();
    }

    @Override
    public void run() {
        while (this.canBeCalled) {
            calledAirport.newCall(new Airplane(calledAirport));

            try {
                Thread.sleep(Utils.getNextCallTime());
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}