wich american flag never flies at half mast?

Answer 1

Mine.

Answer 2

Observances:

30 days for President (current or former)
10 days for Vice President, Chief Justice of Supreme Court (current or former), Speaker of the House
From day of death until interment for Associate Justice of the Supreme Court, Secretary of Executive or Military Department, former Vice President, Governor of State, Territory or possession.
On the day of death and the following day for a member of Congress.
On Memorial Day (last Monday of May in the U.S.), the flag is traditionally displayed at half mast from dawn until noon and at full mast for the remainder of daylight.