Aircraft Maintenance Technicians (AMTs) spend up to 30% of work time searching manuals, a documented efficiency bottleneck in MRO operations where every procedure must be traceable to certified sources. We present a compliance-preserving retrieval system that adapts LLM reranking and semantic search to aviation MRO environments by operating alongside, rather than replacing, certified legacy viewers. The system constructs revision-robust embeddings from ATA chapter hierarchies and uses vision-language parsing to structure certified content, allowing technicians to preview ranked tasks and access verified procedures in existing viewers. Evaluation on 49k synthetic queries achieves >90% retrieval accuracy, while bilingual controlled studies with 10 licensed AMTs demonstrate 90.9% top-10 success rate and 95% reduction in lookup time, from 6-15 minutes to 18 seconds per task. These gains provide concrete evidence that semantic retrieval can operate within strict regulatory constraints and meaningfully reduce operational workload in real-world multilingual MRO workflows.

翻译：飞机维修技术人员（AMTs）在查找手册上花费高达30%的工作时间，这是维修、修理和大修（MRO）操作中一个已记录在案的效率瓶颈，其中每个程序都必须可追溯至经认证的来源。我们提出了一种合规性保持的检索系统，该系统通过适配LLM重排序和语义搜索技术，使其在航空MRO环境中与经认证的遗留查看器协同工作，而非替代它们。该系统基于ATA章节层次结构构建版本鲁棒的嵌入表示，并利用视觉语言解析技术结构化经认证的内容，使技术人员能够预览排序后的任务，并在现有查看器中访问已验证的程序。在49,000条合成查询上的评估实现了超过90%的检索准确率，同时与10名持证AMTs进行的双语对照研究表明，系统在前10名检索成功率上达到90.9%，并将查找时间从每项任务6-15分钟减少至18秒，降幅达95%。这些成果提供了具体证据，表明语义检索能够在严格的监管约束下运行，并有效减少现实世界多语言MRO工作流程中的操作负担。