Skyhawk 172/Cutlass 172
Flight Crew Private
Flight Crew Last 90 Days 30; Flight Crew Total 140; Flight Crew Type 80
Confusion; Situational Awareness
Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors
[I] flew towards Frederick airport for practice landings. Looked up frequency and [incorrectly] tuned in CTAF of 122.7 (it was actually 122.725). Received AWOS and then. Made radio calls 8 miles out; on 45; downwind; base; and final. Saw a plane in the pattern when maneuvering to enter the pattern; but it was a glider. We didn't hear anyone on the radio and expected it to be quiet because of the gusty wind. After a full stop; taxi back landing we stopped short of the intersecting runway; looked both ways; made a call and crossed. Ran a pre-checklist before departure; checked both finals; made call entering runway and started to takeoff.On the takeoff roll; we noticed a plane flying perpendicular to the runway at 200 FT. It looked like a Piper Arrow with the retractable gear extended. We had no idea where he came from. No beacon; landing lights; or strobe lights were on. We didn't know if he was on final and we didn't see him or he was doing a missed approach or circle to land. They were much faster than us and executed a go-around in front of us while we were on our takeoff roll. After they turned crosswind there was no more conflict. We started freaking out that the Tower; which I understood was open later might have opened early. On double checking the frequency; we realized our error. The combination of being on the wrong frequency and not seeing the airplane on final/circling contributed to the potential conflict.
A C172 pilot reported dialing up the wrong CTAF frequency at FDK airport and experienced a conflict on takeoff roll.