I witness — and perhaps help prevent — an accident at the airport.

This happened a few weeks ago, but “safe pilot” issues are on my mind lately, so I thought it might be a good idea to document the incident here.

I was at the airport chatting with Stan. We were standing on the ramp near where my helicopter was parked. I’d just come in from a flight.

As we were talking, two planes flew by overhead. They were so close that I assumed they were flying together. The first plane turned right into a downwind for Runway 23. The second plane turned left. I guess they aren’t together, I thought to myself.

As Stan and I chatted, I watched the two planes. The second plane was definitely flying a downwind for Runway 5. So both planes were flying downwinds for opposite runways.

Surely one of them will make a call and the other will hear it and the problem will be resolved before it’s a problem, I thought to myself.

But then both planes turned base. They did it at almost the same time. I pointed it out to Stan. A moment later, they were both on final. If they kept going, they’d meet in the middle of the runway with a lot of bent metal.

I rushed over to my helicopter, flicked the Master switch, turned on the radio, and put on my headset. I keyed the mike, and said, “Wickenburg traffic, there are planes on final for runway 23 and runway 5 at the same time.”

The plane on final for runway 5, now only 200 feet above the ground, banked to its right and started climbing. “I called on the radio,” a man’s voice said. There was no other voice. The other plane kept coming and landed.

“I made my radio calls,” the pilot who’d climbed out said. He was clearly getting pissed off.

“Maybe his radio is broken,” I said, trying to soothe him. But I suspected the truth: the other pilot was tuned into Wickenburg’s old frequency, 122.8, which had been changed over a year and a half — or three chart issues — ago.

The pilot still in the air made left traffic for runway 23 and landed. He made calls every step of the way. The other pilot taxied to parking. When he and his wife got out, I saw that they were older folks, probably retired, perhaps too cost-conscious to spend $8 on an up-to-date Phoenix Sectional Chart. Or too complacent to check the frequency before coming in.

By this time, Stan and I had said our goodbyes and Stan went on his way. I went over to the older couple to ask if they needed help parking their plane. I also asked if their radio was working right. They told me they thought it was. I told them what had almost happened — they were completely unaware of the other plane flying straight toward them over the runway. I asked if they were on the right frequency, pointing out that it had been changed about a year and half before. The pilot got a little flustered and said he was pretty sure they were.

I didn’t believe him, but I wasn’t about to challenge him. Not my job. I think my gently applied comments were enough to get him to either check the radio before takeoff or check the frequency. That’s all I wanted to do.

As for the second pilot, he taxied to fuel . To his credit, he didn’t approach the other couple.

The FAA rules regarding radio communications are clear: radio communications are not required in Class G airspace. So technically, the first pilot hadn’t done anything wrong.

But if the two planes had crashed and the NTSB had come in for an investigation, what do you think they would have found? Perhaps one plane’s radio tuned into the wrong frequency.

And who do you think would have been to blame for the accident? That’s a trick question, of course. The NTSB would have blamed both pilots. One for not communicating on the right frequency and both for not looking out for traffic.

If you’ve read as many NTSB reports as I have, know how they make their conclusions. If it’s not mechanical, it’s usually pilot error. And since radio communications are not required at Class G airspace, the pilot has the additional important burden of looking out for and avoiding other traffic.

What I learned from all this is that some idiots don’t use the radio when they should. They might have a good excuse: they don’t have a radio or it’s broken. (I once had to fly into Wickenburg with a broken radio and I snuck in as far away from the traffic pattern as possible, nearly hugging the ground until I got to the helipad.) Or they might have a bad excuse, like they had the wrong frequency tuned in or “it isn’t required so I don’t do it.” That’s sheer carelessness or stupidity.

Because you can’t depend on the radio to alert you to traffic, you have to keep a constant lookout for it, especially when you’re near an airport. Trusting your ears to alert you to traffic can kill you in Class G airspace, so I’m always looking out for other traffic. Why other pilots don’t, is a mystery to me.

I’m glad this turned out to be a non-event. But, at the same time, I’ll always wonder what would have happened if I — or someone else, for that matter — hadn’t been out there and taken action.