In order to have safe operation, it is imperative that you maintain good communication with ATC. The controller ’ s understanding can be enhanced by you responding appropriately and using standard phraseology. Communication failure describes an aircraft without a radio (NORDO), even among pilots and others who are not air traffic controllers. While sometimes used to denote small general aviation aircraft that are not equipped with one, the term is more commonly applied to aircraft that have experienced a radio failure in midair. This may constitute an emergency, as determined by the pilot. Transmissions should be well thought out before keying the transmitter. Know what needs to be said and always check the radio frequencies to ensure that the proper one is being used to transmit. Aircraft equipped with a transponder should indicate a NORDO situation by setting the appropriate transponder code: 7600. NORDO aircraft declaring an emergency are given priority over other aircraft if a more serious emergency does not occur on another aircraft. If the radio failure occurs in VFR conditions in an area where radio communication is required, the pilot is expected to continue under VFR and land when feasible. In IFR conditions, the pilot is expected to follow the last instructions given. Air traffic control may re-establish communications with NORDO aircraft by using emergency frequencies, voice features of NAVAIDs, or aviation light signals. In the event of one-way communications (i.e. aircraft can receive only), the controller may request the aircraft make identifying turns, flash their navigational lights, transmit codes or IDENT signals on the transponder, rock their wings, etc, to acknowledge clearances or instructions.