Narrative:

I was acting controller in charge in a standalone position. Runway 8 was the active runway. Aircraft X called the tower via cell phone and reported 20 miles northwest reporting that he had gone NORDO. I coordinated with local control and I gave him the pattern entry (left base runway 8) via phone plus the wind and altimeter and told him to call back when he was 5 miles northwest so that we could try and spot him with the binoculars. Then aircraft Y called tower; on 118.2; 5 miles south and was issued a pattern entry/wind and altimeter and to report 2 miles to which he responded that he was 2 miles immediately. Aircraft Y was then issued a landing clearance. While aircraft Y was on landing roll; aircraft X called via phone to report 5 miles northwest and we were able to spot him and give him light gun signals. At this time aircraft Z called up for taxi from the northwest ramp for a northeast departure and requested an A3 intersection departure. He was instructed to taxi to runway 8 @ A3 hold short of alpha for the inbound aircraft the NORDO and aircraft Y. Due to the short cord on the light gun I was assisting the local controller with the light gun so that he could be on position to respond to radio calls. Meanwhile aircraft Y was issued taxi instructions turn left at A4 taxi via alpha cross runway 12/30. Aircraft Y remained on A4 holding short of alpha for unknown reasons. Local made a blanket broadcast to go along with the light signals to clear aircraft X to land as he was on short final. Realizing he had an alternative option of departing aircraft Z on runway 30 at a; the local controller offered runway 30 at a to aircraft Z. Aircraft Z accepted the offer and advised he needed a little time for his run-up. Local which was also combined with ground then went back to aircraft Y and issued taxi instructions to hold short of runway 30 (upon review of the audio aircraft Y did not read back the hold short clearance and just responded xyz; also local was calling him by the wrong call sign). Aircraft Y continued holding on A4. By this time aircraft X was on landing roll and was approaching A3 and was given light gun signals to taxi to parking. Local at this time received a ready for departure call from aircraft Z and he issued a takeoff clearance for runway 30 at a to which he responded runway 30 cleared for takeoff. I was giving light gun signals to aircraft X and was focused on him when I heard one of the tower team members state it appears aircraft Z is departing on alpha (westbound). When I diverted my attention from aircraft X who was exiting alpha to the east of aircraft Z; I observed aircraft Z making a sharp right turn to the northeast just west of runway 30 before any alternate instructions could have been issued. Aircraft Y was still sitting on A4 was then reissued taxi instructions to turn right on alpha and taxi to parking cross runway 30.I would recommend being more vigilant and scanning work environment; as pilots sometimes do the unexpected. Additionally our current light gun has a cord that isn't long enough to reach the local control/ground control position and all areas of the tower cab to be effective; so a longer cord for our light gun or a portable option.

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Original NASA ASRS Text

Title: TWF Tower CIC and Approach Controller reported of an aircraft that departed Twin Falls via a taxiway.

Narrative: I was acting CIC in a standalone position. RWY 8 was the Active runway. Aircraft X called the tower via cell phone and reported 20 miles NW reporting that he had gone NORDO. I coordinated with Local control and I gave him the pattern entry (Left Base RWY 8) via phone plus the wind and altimeter and told him to call back when he was 5 miles NW so that we could try and spot him with the binoculars. Then Aircraft Y called tower; on 118.2; 5 miles south and was issued a pattern entry/wind and altimeter and to report 2 miles to which he responded that he was 2 miles immediately. Aircraft Y was then issued a landing clearance. While Aircraft Y was on landing roll; Aircraft X called via phone to report 5 miles NW and we were able to spot him and give him light gun signals. At this time Aircraft Z called up for taxi from the NW ramp for a NE departure and requested an A3 intersection departure. He was instructed to taxi to runway 8 @ A3 hold short of Alpha for the inbound aircraft the NORDO and Aircraft Y. Due to the short cord on the light gun I was assisting the Local Controller with the light gun so that he could be on position to respond to radio calls. Meanwhile Aircraft Y was issued taxi instructions turn left at A4 taxi via Alpha cross runway 12/30. Aircraft Y remained on A4 holding short of Alpha for unknown reasons. Local made a blanket broadcast to go along with the light signals to clear Aircraft X to land as he was on short final. Realizing he had an alternative option of departing Aircraft Z on RWY 30 at A; the local controller offered RWY 30 at A to Aircraft Z. Aircraft Z accepted the offer and advised he needed a little time for his run-up. Local which was also combined with ground then went back to Aircraft Y and issued taxi instructions to hold short of RWY 30 (upon review of the audio Aircraft Y did not read back the hold short clearance and just responded XYZ; also Local was calling him by the wrong call sign). Aircraft Y continued holding on A4. By this time Aircraft X was on landing roll and was approaching A3 and was given light gun signals to taxi to parking. Local at this time received a ready for departure call from Aircraft Z and he issued a takeoff clearance for RWY 30 at A to which he responded RWY 30 cleared for takeoff. I was giving light gun signals to Aircraft X and was focused on him when I heard one of the tower team members state it appears Aircraft Z is departing on Alpha (westbound). When I diverted my attention from Aircraft X who was exiting Alpha to the east of Aircraft Z; I observed Aircraft Z making a sharp right turn to the northeast just west of RWY 30 before any alternate instructions could have been issued. Aircraft Y was still sitting on A4 was then reissued taxi instructions to turn right on Alpha and taxi to parking cross RWY 30.I would recommend being more vigilant and scanning work environment; as pilots sometimes do the unexpected. Additionally our current light gun has a cord that isn't long enough to reach the LC/GC position and all areas of the tower cab to be effective; so a longer cord for our light gun or a portable option.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.