U.S. air traffic controllers have interpreted new “climb via” phraseology to include top or final altitudes as crossing restraints, somewhat contrary to what the industry expected. This has translated into almost every standard instrument departure (SID) becoming eligible for use of the phraseology, according to Rich Boll, a business jet pilot and chairman of NBAA’s ATC and flight technologies working group.

Designed to reduce radio chatter and save time, the new phraseology was implemented “to emphasize the need to look at the arrival or departure plate to comply with vertical, lateral and speed restrictions,” Boll said. Recent blanket implementation of "'climb via' dilutes its effectiveness and has caused confusion among some cockpit crewmembers,” he added.

Because of the NBAA committee’s input, the FAA has agreed in principle to restructure the way controllers issue, receive and confirm “climb via” clearances. These issues, along with a certain informality among pilots when communicating with ATC, have led to a “climb via” phraseology compliance rate of between 10 and 20 percent. Boll added that while ATC properly issues “climb via” clearances, pilots on the whole have not been responding in accordance with the FAA order, a problem that all but negates the intended advantages of the procedure.