After you’ve cleared a few groups of Nazis, you are ordered to take out a halftrack. The halftrack appears on your objective screen at the back-left of the area. You can toss a grenade in that direction by peering over the middle barbed wire section and arcing a grenade into the back of the truck. You just need to get close to achieve success. If you need more grenades, you can get them from Stiles. Once that is complete, you need to hold out for a few more seconds for your P-47s to arrive.
No Sanctuary
Complete Stronghold to unlock this achievement/trophy.