直升机地面勤务 helicopter tender

地面勤务转换继电器 ground service transfer relay

地面勤务选择继电器 ground service select relay

地面勤务费用 Ground Operation Expenses

地面勤务车 [车辆] [航] ground-support vehicle

地面勤务继电器 ground service relay

地面勤务汇流条 ground service bus