 Extending the products liability insurance for their continued use after the movie was not possible so National kept the wings in-house for many years in case a sequel was considered.The wings were destroyed around 1979 so that there would be no possibility of their re-installation.The Batcopter has been retrofitted with new equipment and electronics so that it can now attain altitudes up to 18000 feet, speeds up to 105 miles per hour, and flight times up to 2 hours and 45 minutes.