Learning Objective 062.03.04.02.07: State that in addition to the information provided, on request from ATC, a special position identification (SPI) pulse can be transmitted but only as a result of a manual selection by the pilot (IDENT button).

The pilot may manually transmit a Special Position Identification (SPI) pulse when the "IDENT" button on the pilot's transponder is pressed. By pushing the “IDENT” button, the transponder transmits an additional pulse at the end of the normal response pulse train.

The benefit of the squawk "IDENT" function is a manual identification of the aircraft. The controller may ask via the radio communication frequency to "IDENT" in case of any doubt of identification on the controller display. Upon acquisition of the SPI pulse, the transponder indication changes/begins to flash on the controller's radar display for approximately 20 seconds. This produces a distinctive display so that a controller can pick out a particular aircraft by asking the pilot to “Squawk Ident”.