This plane was named the B-17G Flying Fortress, and for good reason. It carried a modest bombload and had thirdteen .50 cal machineguns for self-protection. The "G" model is distinguished by the chin turret under the nose.
You can clearly see the Norden bombsight in the Plexiglass nose. This was the most accurate device than any other country's airforce.
The yellow bombs represent bombing missions which the plane flew. If the crew completed twenty-five combat misions. The crew would end their combat tour and will be rotated back to home. Unfortunately, not too many crews didn't return home.