Narrative:

Squawked VFR (1200) in the sfra. Returned to work as flight instructor after being gone for about three months due to closures caused by the covid-19 virus. First day back at ZZZ. Flying with xx year old student who tends to skip around checklists (it was his first day back; too); I usually watch him like a hawk because of this tendency. Still; he managed to miss the 'transponder' item and somehow it got past me. Even still; I normally double (sometimes triple) check the transponder as part of my pre-takeoff flow. Because of my extended absence and lack of proficiency in the sfra; I forgot to double check and took off with 1200 on the transponder. In order to resolve this issue; I need to keep a closer watch on my students; as I am the PIC. Aircraft is based in ZZZ; so transponder should be set to 12XX as its default squawk code. I must be more adamant about checking my transponder before takeoff.

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Original NASA ASRS Text

Title: Instructor pilot reported taking off with incorrect transponder code and cited lack of flying due to the COVID-19 as a contributing factor.

Narrative: Squawked VFR (1200) in the SFRA. Returned to work as flight instructor after being gone for about three months due to closures caused by the COVID-19 Virus. First day back at ZZZ. Flying with XX year old student who tends to skip around checklists (it was his first day back; too); I usually watch him like a hawk because of this tendency. Still; he managed to miss the 'transponder' item and somehow it got past me. Even still; I normally double (sometimes triple) check the transponder as part of my pre-takeoff flow. Because of my extended absence and lack of proficiency in the SFRA; I forgot to double check and took off with 1200 on the transponder. In order to resolve this issue; I need to keep a closer watch on my students; as I am the PIC. Aircraft is based in ZZZ; so transponder should be set to 12XX as its default squawk code. I must be more adamant about checking my transponder before takeoff.

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.