When resting next to the wreckage he had got bitten by a snake and had crept into the cockpit to die there.

wreckage 是名词，由动词 wreck（破坏、毁坏）加上名词后缀 -age 构成，表示"残骸、碎片"，特指飞机、车辆等交通工具被毁坏后剩下的部分。