In the 1960s, NASA experimented with this concept with the Northrop X-21, a converted Douglas WB-66D.
Transport Layer Security | Layer Marney | Boundary Waters Canoe Area Wilderness | Boundary Commission | Simple Authentication and Security Layer | Ozone layer | List of Buckinghamshire boundary changes | Interstellar Boundary Explorer | Regional District of Kootenay Boundary | Ozone Layer | Oregon boundary dispute | MPEG-1 Audio Layer II | List of Berkshire boundary changes | Boundary-Similkameen | Boundary marker | Boundary Dam | boundary (cricket) | Boundary Creek | boundary | ATM Adaptation Layer 5 | United States and Mexican Boundary Survey | Thin layer chromatography | Sattler's layer | Quartz (graphics layer) | Physics Abstraction Layer | ozone layer | Outflow boundary | Ontology Inference Layer | Local Government Boundary Commission for England (1972) | Local Government Boundary Commission for England |