Maintenance of NAS enroute stage a air traffic control system. 

 - [Washington, D.C.,  1971]. 
 - xxxvi, 790 p. :  ill. 
<br/><br/> [Handbook].  Dec. 6, 1968, and Changes 1-4, [1969-1971].  [Reprinted Oct. 4, 1971].  Cover title.  4to.  [Reprint to include Changes. Issued with perforations].  CRDP Program Historic Shelflist record. 
<br/><br/> Official use. Not available. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Air traffic control.
<br/><br/><label>Gov. Doc. Class. No.: </label>TD 4.8/2:6100.1/2