Narrative:

Takeoff and landing practice were conducted without the transponder operating. The transponder in this citabria requires that a toggle switch on the left overhead panel be 'on,' as well as the integral radio switch being in the 'altitude' position, to have the transponder operate. During the before takeoff checklist, the switch integral to the radio was turned on, but the wrong toggle switch was turned on, resulting in the transponder not being on. This situation boils down to the fact that I made a mistake, but there are a couple of interesting contributing factors and things to think about: 1) the toggle switches are above, and behind, the front seat pilot's head, making them hard to see and identify in the best of circumstances. 2) when wearing a parachute and with the harness cinched tight, it is a stretch to turn around far enough to clearly read the switch placards. This is especially true for wearers of bifocals., because the awkward head position forces one to look out the edge of the glasses, not the center, making it harder to focus. 3) switches in this aircraft are labeled 'radio 1,' 'radio 2,' etc, not with the name of the actual radio being switched. 4) during takeoff and landing practice in a tailwheel aircraft, attention was focused everywhere except the 'reply' light of the transponder. Also, there was no interaction with ATC. This meant the problem was not noticed until postflt shutdown. I will evaluate making changes to the sequence in which I perform the tasks on my printed before takeoff checklist, primarily having to do with seatbelt tightening, and will be more positive in mycockpit.

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Original NASA ASRS Text

Title: A CH7A PLT PRACTICES LNDG WITHOUT USING THE XPONDER WITHIN THE 30 NM MODE C VEIL IN THE DENVER CLASS 'B.'

Narrative: TKOF AND LNDG PRACTICE WERE CONDUCTED WITHOUT THE XPONDER OPERATING. THE XPONDER IN THIS CITABRIA REQUIRES THAT A TOGGLE SWITCH ON THE L OVERHEAD PANEL BE 'ON,' AS WELL AS THE INTEGRAL RADIO SWITCH BEING IN THE 'ALT' POS, TO HAVE THE XPONDER OPERATE. DURING THE BEFORE TKOF CHKLIST, THE SWITCH INTEGRAL TO THE RADIO WAS TURNED ON, BUT THE WRONG TOGGLE SWITCH WAS TURNED ON, RESULTING IN THE XPONDER NOT BEING ON. THIS SIT BOILS DOWN TO THE FACT THAT I MADE A MISTAKE, BUT THERE ARE A COUPLE OF INTERESTING CONTRIBUTING FACTORS AND THINGS TO THINK ABOUT: 1) THE TOGGLE SWITCHES ARE ABOVE, AND BEHIND, THE FRONT SEAT PLT'S HEAD, MAKING THEM HARD TO SEE AND IDENT IN THE BEST OF CIRCUMSTANCES. 2) WHEN WEARING A PARACHUTE AND WITH THE HARNESS CINCHED TIGHT, IT IS A STRETCH TO TURN AROUND FAR ENOUGH TO CLEARLY READ THE SWITCH PLACARDS. THIS IS ESPECIALLY TRUE FOR WEARERS OF BIFOCALS., BECAUSE THE AWKWARD HEAD POS FORCES ONE TO LOOK OUT THE EDGE OF THE GLASSES, NOT THE CENTER, MAKING IT HARDER TO FOCUS. 3) SWITCHES IN THIS ACFT ARE LABELED 'RADIO 1,' 'RADIO 2,' ETC, NOT WITH THE NAME OF THE ACTUAL RADIO BEING SWITCHED. 4) DURING TKOF AND LNDG PRACTICE IN A TAILWHEEL ACFT, ATTN WAS FOCUSED EVERYWHERE EXCEPT THE 'REPLY' LIGHT OF THE XPONDER. ALSO, THERE WAS NO INTERACTION WITH ATC. THIS MEANT THE PROB WAS NOT NOTICED UNTIL POSTFLT SHUTDOWN. I WILL EVALUATE MAKING CHANGES TO THE SEQUENCE IN WHICH I PERFORM THE TASKS ON MY PRINTED BEFORE TKOF CHKLIST, PRIMARILY HAVING TO DO WITH SEATBELT TIGHTENING, AND WILL BE MORE POSITIVE IN MYCOCKPIT.

Data retrieved from NASA's ASRS site as of July 2007 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.