If you reside in a historic district, to conduct work to the exterior of your historic property, you are required to obtain a Certificate of Appropriateness (COA). A COA is a special permit obtained in addition to the regular building permitting process.
The recommended arrival time at the airport is 75 minutes prior to departure when traveling within the United States. You must be checked in at least 30 minutes before your scheduled departure time.
In-Town. By going to Hong Kong International Airport via Airport Express (AEL), you may choose to check in at either Hong Kong or Kowloon station of the MTR. You can simply check in and collect your boarding pass as early as one day in advance or as late as 90 minutes before departure.