The Federal Aviation Administration (FAA) will temporarily suspend online registration for small Unmanned Aircraft Systems (UAS) Wednesday night to complete a second round of planned site maintenance in advance of an expected rush of customers on Christmas Day.

The registration site was taken offline Tuesday night for initial maintenance and updates before being returned to service Wednesday morning. The FAA will take the site offline Wednesday at 11 p.m. Eastern. The site is expected to return to service around 6 a.m. on Thursday.

The agency has seen strong initial demand, with more than 45,000 registrations completed by the close of business on Tuesday. While an overwhelming number of people have successfully registered, a small number of users reported performance issues. The FAA instructed its contractor, CSRA, to address these issues and to complete other maintenance in advance of the post-holiday demand.

According to industry estimates, as many as 400,000 small UAS could be sold during the holidays.

The FAA is requiring registration of all aircraft weighing more than 0.55 pounds (250 grams) and less than 55 pounds (approx. 25 kilograms), including payloads such as on-board cameras.

Registration will foster a greater awareness on the part of users to learn the rules about flying safely in the National Airspace System. Registration will also enable the FAA to trace the ownership of an aircraft in the event of an incident.

Owners who previously operated an unmanned aircraft exclusively as a model aircraft prior to December 21, 2015, must register no later than February 19, 2016. Owners of any other UAS purchased for use as a model aircraft after December 21, 2015 must register before the first flight outdoors.

Owners using the model aircraft for hobby or recreation will only have to register once and may use the same identification number for all of their model UAS. The registration is valid for three years.