As we sat in the run-up area before departing Watsonville (KWVI), I called NorCal on the radio to get the IFR clearance over to KSNS for the ILS approach. KWVI is a non-towered field, meaning no one controls the airspace and that pilots use the common traffic advisory frequency (CTAF) to announce positions and intentions. We're all working together in that environment. It's crowd-sourced tower ops.
It's all great, with one caveat: no radio is required in this airspace. So that means that not every plane and pilot may be participating. This makes it über-important to use those VFR traffic scanning skills and be responsible for your own safety and separation.
This was brought into very clear focus after we received the clearance, checked for traffic, announced our intentions and rolled across the ILS threshold believing everything was safe and that we had the right-of-way. Luckily the run-up area has an odd shape, and as I glanced up the final approach before entering the runway, sure enough, there was a little Cub descending to land! Brakes! We stopped short of the runway threshold and watched him land. He was probably cursing us; I hope he would have been able to perform a go-around had we taken the runway.
Let's look for explanations.
First and most obvious, is that by a stroke of (un)luck, when we visually checked the pattern for traffic, that plane must have been behind the high right wing of our Cessna. We couldn't see him.
Second, we verified that we were talking and listening on the appropriate CTAF, not still accidentally tuned to NorCal or another frequency by mistake. Confirmed. If the other pilot was radio-equipped, he was not talking on this frequency. He was wearing the unmistakeable mint-green David Clarks, so he at least was equipped for comm, whether his plane was or not.
Jason relayed a conversation that he had had with an "old timer" who always incorporated a 360-degree turn at the end of his run-up before taking the runway. It seemed like overkill, but such an operation would have revealed the other traffic that surprised us.
Thankfully it was not even a near accident. Just a learning experience.
