James L. Robart on 3rd February 2017. The en banc procedure is explained here. In the event, it seems that the President has decided (or been advised) to issue a new Executive Order. Consequently, the en banc hearing was stayed and did not proceed - read the court's announcement. On 15th March 2017, the appeals court issued an Order indicating some disagreement within the judiciary as to whether the order staying the pending appeal should have been considered en banc.
Executive Order No. 13769 of 27th January 2017 - "Protecting the Nation from Foreign Terrorist Entry into the United States".
Documents etc filed in the case may be seen via - State of Washington and State of Minnesota v Trump
Executive Orders issued by various Presidents may be seen via the Federal Register.
A useful explanation of Executive Orders is available at CNBC - Executive Orders: what they are and how they work
8th March 2017 - given that President Trump issued a new Executive
Order replacing EO 13769, the case of States of Washington and Minnesota v Donald J Trump
ended - see the court's announcement.