In what is seen as a challenge to the incoming Obama administration, President Bush issued an executive order on November 18 dictating "effective implementation of the Next Generation Air Transportation System [NextGen]." The first deadline for establishing a DOT support staff is set for no more than 60 days after the order, or by January 17. President-elect Obama's inauguration is January 20. The first of Bush's deadlines is followed up with a next phase, set for 120 days later, dictating the establishment of an advisory committee to the Secretary of Transportation. Pilots and aircraft owners are concerned that equipment requirements for NextGen could be excessively expensive and might not adequately consider some pilots' real-world needs. Though President Bush has put forward the order, the Obama administration retains the right to review such administrative orders and has the right to rescind or replace such orders at its discretion.