From episode 2x03 "The Most Crucial Game".
The military helicopter equipped with light panels for communication lifts off and heads towards the alien spacecraft.
Marine One lands at the airport and the President and his staff load onto Air Force One to escape.
From episode 5x04 "Fire Sale".
A pair of SD-6 agents meet with Marcus as he arrives back in town and ask about Sydney in episode 1x01 "Truth Be Told". Sydney passes the disks to Vaughn to give the CIA a chance to copy their data in episode 1x02 "So It Begins".
From episode 2x23 "Image in a Cracked Mirror".
From episode 13x01 "Bees Are Much Calmer Than All This!".
Harry and Ellen talk before Harry's flight to Florida.
From episode #112 "I'll Take Manhattan".