The FAA said numerous pilot deviation reports–some involving loss-of-separation violations–have been filed surrounding the use of the relatively new “climb via” phraseology instituted in early April. Despite the agency’s acknowledgement of some misunderstandings with the new phraseology attached to updated standard instrument departures, the FAA recently reminded users that it is the pilot-in-command’s responsibility to ensure compliance with an ATC clearance.The agency suggested pilots identify the appropriate initial altitude to maintain as described on the SID chart or assigned by ATC prior to takeoff, being careful not to confuse it with altitude restrictions or expected final altitude. Use of correct phraseology is also imperative because pilots are required to respond to climb- or descend-via clearances by repeating the “climb/descend via” clearance verbatim. Abbreviated readbacks can result in controllers repeating instructions until pilots give a verbatim readback. Pilots should comply with proper “climb via” phraseology on initial climbout radio transmissions to ATC, avoiding the use of phrases such as “on the” or “climbing on,” which can create confusion and additional ATC workload to verify what the pilot actually received. When changing frequencies, pilots must advise ATC on initial contact of current altitude, “climbing via/descending via” with the procedure name and runway transitions if assigned. If assigned an altitude or speed not contained in the procedure, the pilot must advise ATC of restrictions issued by a previous controller.