Canceling or closing flight plans. 

 - [Washington, D.C.,  1975]. 
 - v. 
<br/><br/> 3/25/75.  CRDP Program Historic Shelflist record. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Air traffic rules.
<br/><br/><label>Gov. Doc. Class. No.: </label>TD 4.8/5:91.83-1 A