I'm just citing regs because his ticket could be at risk if he doesn't follow them.The number of times I've been given a heads up on someone flying into/through Class C's without a transponder is in the neighborhood of 1-5%
Doesn't make it any easier knowing they'll be inbound at some time today (maybe) compared to if they call me when they get into radio coverage.
And for some reason, I'm surprised that Bob would want to fly along the border through the C compared to staying north and bypassing it.
I flew west to east through ELP a couple years ago. They asked me which transition I wanted and I would have had no idea what they were talking about if not for the aircraft that called up 5 minutes before I did and requested a "downtown transition." That sounded like what I wanted, so I said the same thing, and luckily I guessed right that downtown was near the border just southeast of the Franklin Mountains.Aeronca Chief with handheld. 65 hp limits how far north I can go. I have been doing the reever since 1966 - always easy. At a thousand feet, it would probably be a single engine 737 that would present a conflict. As I recall, with a full boat and both engines I was well above that and westbound just barely south of that big mountain.
I see no reason to not follow the regs when it is easy to do so. I will give them a call from Van Horn with a +/- 5 minute estimate, and call on the frequency at Fabens. I will let you know how it goes.
I will double-check the reg, but if under the floor of either class B or C, I am not required to do anything. That is changing rapidly, but it will have to be NPRM. EL PASO's class C appears to go to the ground at the border. Locals tell me they do it all the time, but I see no point in not doing it the right way.