All crewmembers have a health bar. These diminish when the plane is shot. When all health is gone, they fall on the floor and you have some time to revive them. If you fail to revive the downed character, he dies. The character lays on the floor of your plane. No injury is shown. When injured or dead, a skull icon appears next to the character. The characters themselves are non-detailed and have a cartoony appearance.
When your plane crashes, it can either explode or disintegrate into pieces. There is a chance a few crewmembers survive this crash. In the de-briefing, these are shown as either KIA or MIA. However, you don’t see any wounded characters when the plane has crashed.

The enemy planes that are shot down, or the targets that you bomb, explode. These types of violence can be indicated as implied violence, since no characters are seen, but it’s clear these planes and buildings are controlled by humans.