Air traffic control
Subtitle: paper 27-48/DO-12. May 12, 1948
Published: 1948
Place of publication: [Washington
Language: eng
Number of pages: 91
Subjects: Air traffic control
Notes: Cover title

"Supersedes: RTCA paper, 9-48/DO-9 dated 2-16-48 [and] RTCA paper 10-48/DO-10 dated 2-17-48."