Narrative:

Issue: as the pilot in command (PIC) I failed to establish two way communication with tower before taxi and takeoff.contributing factors: 1) I failed to see that my transmitter selector knob was on COM2 which was dialed to 121.5. 2) I believed based upon [website information] that the tower was closed at xd:00 and the field was uncontrolled 3) the runway lights and taxi lights were off which also led me to believe that the tower was closed 4) while I made traffic calls and attempted to activate the pilot controlled lighting by using the radio - I was actually transmitting on 121.5 guard frequency 5) at the same time; the runway and taxi lighting system was going on and off which led me to believe that the pilot controlled lighting attempts were having effect but would not stay on 6) what was likely happening was the tower controller was attempting to get my attention by turning the lights on and off 7) when landing earlier that evening at approximately xa:30 in the early evening; the tower controller - as the routine; asked me to taxi to the ramp and monitor ground. 8) as this aircraft's radio system does not monitor two frequencies well on the ground and I uncharacteristically switched the transmitter selector to COM2 and monitored the ground frequency. 9) this aircraft's COM2 radio defaults to 121.5 guard whenever it is restarted; so failing to see or remember that I had moved the transmitter selector to COM2 at the end of the last flight; I was broadcasting on COM2 121.5 when I thought I was broadcasting on the CTAF and tower frequency; 10) the problem was discovered when after takeoff; I flipped COM1 frequency to approach and announced tail number and altitude departing from ZZZ; as I was still broadcasting on COM2 121.5 the approach controller advised that I was broadcasting on guard - at which time I realized my transmitter selector was on COM2 rather than COM1. 11) I immediately switched the transmitter selector to COM1 and resumed communication with approach controller. 12) I did switch back to the tower controller frequency and apologize who correctly pointed out that the hours of operation are advertised and consistent. 13) upon review of the AFD data that was available on my [tablet] I could have determined that the hours of operation were until xe:00 local rather than the xd:00 presented on [the website information]. 14) during my preflight briefing with FSS I could and should have inquired as to the tower's hours of operation 15) human factors: the airport lighting going from on to off at the same time of my belief I was activating pilot controlled lighting led me to believe I was transmitting on the CTAF and tower frequency both in announcing my position and intentions and believing my mic clicks were at least activating the taxi and runway lighting. Corrective actions: 1) I will in the future consult the AFD data when in doubt as to the tower operating hours 2) I will always attempt to pick up clearances on the ground; although in this instance it would not have been through the tower but rather through FSS frequency; 3) before taxi; I will always seek to establish two way communication with ATC or FSS simply to make sure the aircraft radios are working properly and that what I believe the transmitter selector is selected to is in fact what it is selected. 4) while I make it a practice to monitor 121.5 in COM2; it is what ultimately allowed the system and me to discover the problem 5) I will not let the absence of taxi and runway lighting lead me to believe that the tower is closed. Possible preventive actions: if the tower monitored 121.5 perhaps it could have redirected me as did the approach controller.

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Original NASA ASRS Text

Title: A pilot departed a towered airport using CTAF procedures on 121.5 while the Tower was open because he had referenced [website] data which indicated the Tower closed at XD:00 local when in fact it closed at XE:00. The aircraft's Communications system confusion was a contributing factor.

Narrative: Issue: As the Pilot in Command (PIC) I failed to establish two way communication with Tower before taxi and takeoff.Contributing Factors: 1) I failed to see that my transmitter selector knob was on COM2 which was dialed to 121.5. 2) I believed based upon [website information] that the Tower was closed at XD:00 and the field was uncontrolled 3) The runway lights and taxi lights were off which also led me to believe that the Tower was closed 4) While I made traffic calls and attempted to activate the pilot controlled lighting by using the radio - I was actually transmitting on 121.5 Guard frequency 5) At the same time; the runway and taxi lighting system was going on and off which led me to believe that the pilot controlled lighting attempts were having effect but would not stay on 6) What was likely happening was the Tower controller was attempting to get my attention by turning the lights on and off 7) When landing earlier that evening at approximately XA:30 in the early evening; the Tower Controller - as the routine; asked me to taxi to the ramp and monitor Ground. 8) As this aircraft's radio system does not monitor two frequencies well on the ground and I uncharacteristically switched the transmitter selector to COM2 and monitored the Ground frequency. 9) This aircraft's COM2 radio defaults to 121.5 Guard whenever it is restarted; so failing to see or remember that I had moved the transmitter selector to COM2 at the end of the last flight; I was broadcasting on COM2 121.5 when I thought I was broadcasting on the CTAF and Tower Frequency; 10) The problem was discovered when after takeoff; I flipped COM1 frequency to approach and announced tail number and altitude departing from ZZZ; as I was still broadcasting on COM2 121.5 the approach controller advised that I was broadcasting on guard - at which time I realized my transmitter selector was on COM2 rather than COM1. 11) I immediately switched the transmitter selector to COM1 and resumed communication with approach controller. 12) I did switch back to the Tower controller frequency and apologize who correctly pointed out that the hours of operation are advertised and consistent. 13) Upon review of the AFD data that was available on my [tablet] I could have determined that the hours of operation were until XE:00 local rather than the XD:00 presented on [the website information]. 14) During my preflight briefing with FSS I could and should have inquired as to the Tower's hours of operation 15) Human Factors: The airport lighting going from on to off at the same time of my belief I was activating Pilot Controlled Lighting led me to believe I was transmitting on the CTAF and Tower Frequency both in announcing my position and intentions and believing my mic clicks were at least activating the taxi and runway lighting. CORRECTIVE ACTIONS: 1) I will in the future consult the AFD data when in doubt as to the Tower operating hours 2) I will always attempt to pick up clearances on the ground; although in this instance it would not have been through the Tower but rather through FSS frequency; 3) Before taxi; I will always seek to establish two way communication with ATC or FSS simply to make sure the aircraft radios are working properly and that what I believe the transmitter selector is selected to is in fact what it is selected. 4) While I make it a practice to monitor 121.5 in COM2; it is what ultimately allowed the system and me to discover the problem 5) I will not let the absence of taxi and runway lighting lead me to believe that the Tower is closed. POSSIBLE PREVENTIVE ACTIONS: If the Tower monitored 121.5 perhaps it could have redirected me as did the approach controller.

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.