TC, at your facility is ground traffic permitted to enter any runway or movement area without explicit clearance?
No. And I don't see that I've said anything to give that impression.
It's real simple. There are many frequencies in the tower, and on the mid they're generally all combined to one position. If one person's working, even if they choose the have ground on speaker at GC, and tower at tower, cd at cd, etc, it's still one person working all frequencies. Tows call very regularly on GC. Pushbacks (for departure) call very regularly on gate or cd. Taxi out on that freq, too. Vehicles are often on tower freq, but I have 3 of those, and may be using any one with any of them. The point is I have them all up for a reason, and that is I'm requirred to, because you never know when someone will call on one. Maybe they SHOULD call me on 128.8, but they call on 132.22 instead. That could be an arrival, a vehicle, a tow, it could be the bogeyman. I answer them on that freq because, again, I have them all up.
It takes little imagination to imagine that I could tell a tow/runup to go from point a to b by crossing rwy 33l. I could then authorize a vehicle to proceed on 33l on a different freq. Then I pass out or fall asleep. While those two ops are taking place on 2 different freqs (THEY don't even know about each other!) Here comes AAL who blithely decides since he hears nobody on 128.8, he'll just announce he's landing! Hey cool! He saw it on the news and that went well. So AAL on 128.8 lands on top of the vehicle who was on 132.22 and then plows into the runup crossing the rwy on 121.9.
This is why if you read the avherald article cited above Babbit says all radar controllers are being reminded to (if this happens again) offer the planes the option to divert. That's what should have happened. If by this point you can't see it, can't see why, I can't help you. This is NOT a ctaf scenario. Not by a long shot.
No need to get so bloody offensive.
But you also seemed to miss my point, which others asked you for clarity on. My point is that most airports.. and yes, I said MOST
airport (meaning, not ALL) use the Tower frequency as the CTAF. Others do not. KDCA, according to AeroNav, has a UNICOM of 122.95. My point is that these pilots could have broadcast their intentions on both Tower's frequency and UNICOM and got their intentions heard by other pilots in the area.
As far as ground operations go, you should re-read my post again. Specifically:
Have a listen to any feed (KLAS for sure) when a runway inspection is being done. You'll notice that all airport ops vehicles tune and broadcast on tower's frequency.
All airport ops vehicles when performing a runway inspection are tuning to, listening to, and broadcasting on Tower's frequency. I did not say WHICH frequency (and yes, I know about multiple frequencies for Tower (that's why I'm so familiar with them at LAS), but that they are on Tower's frequency. Another thing to consider is combining the multiple positions onto a single frequency, as they tend to do at night, and broadcast what that frequency is on the ATIS. Whether airport ops listens to the ATIS prior to doing anything on the ground is a good question, but they definitely have the means to get the right frequency and be tuned to the right frequency before performing their inspections.
How you read so deeply into what I was saying to say that everything I said is dead wrong, I really do not know.
As far as the avherald article, I agree. Potomac should have offered the diversion. Why they didn't is a good question. But how you read so deeply into my post to pick out what you think I was saying is beyond me.