Coming off of their Bye, the Chargers traveled to M&T Bank Stadium to take on the Baltimore Ravens.  The Chargers drew first blood as QB Philip Rivers completed a 31-yard TD pass to WR Malcom Floyd.  However, the Ravens would tie the game up with QB Steve McNair completing a 5-yard TD pass to TE Daniel Wilcox.  In the second quarter, kicker Nate Kaeding would give the Chargers some comfort, as he kicked a 34-yard and a 54-yard field goal (a then career long) to give San Diego the lead at halftime. After a scoreless third quarter, the Ravens slowly started to climb back.  Late in the fourth quarter, after giving Baltimore an intentional safety (instead of punting deep from their own end zone), the Chargers hoped that their defense could hold up and prevent any chance of a comeback.  Unfortunately, McNair led the offense throughout the closing minutes and scored the game-winning touchdown with a 10-yard TD pass to TE Todd Heap.  With their loss, the Chargers fell to 2-1.
Question: What was the longest TD pass?
Answer: 31-yard TD pass