AirVenture 2018: ADS-B’s Dark Side

In the old days, when you freelanced in the clouds without a clearance, you could at least assume no one else was doing the same.

Anyone who's been to AirVenture in weather other than the crystalline blue skies that this show often enjoys knows—or should know—one overarching fact about Oshkosh air operations: IFR and AirVenture don't mix very well. While some people insist on flying IFR into Oshkosh just because they file IFR to go everywhere, it's really not a good idea. ATC imposes a slot system for arrivals and although it handles reasonable volume, when the weather really tanks, as it did Sunday morning, arrivals will slow to a crawl.

But that's not really the problem. The problem is marginal VFR or IFR, conditions that are two sides of the same coin. When the weather is just flyable enough to sort of remain clear of clouds—but not really—a certain hysteria sets in. Think of it as Oshkosh's unique version of gethomeitis. Now throw ADS-B into the mix and you have a new, technologically aided form of aeronautical terror.

I hadn't realized how bad this can be until I talked to James Buck of Aspen Avionics when we were shooting a video Sunday afternoon. Buck and Aspen CEO John Uczekaj had flown in earlier in the day and Buck showed me a screen grab of their course before they put the airplane down at an airport short of Oshkosh.

The course was a winding, serpentine line that looked like the last piece of spaghetti in the bottom of the pot. Buck said some of that was to avoid clouds, but a lot more of it was to avoid airplanes stooging along—sans IFR clearance—in clouds, but visible as ADS-B targets. He said the entire area was so dense with traffic that they decided to land short, along with dozens of other airplanes finally seized by sanity. When the weather cleared, they continued the trip.

I'm not sure whether ADS-B makes this sort of thing safer or aggravates it, but it has been going on since long before the EAA Fly-in and Convention morphed into AirVenture. About 20 years ago, I got my own taste of it when I departed Oshkosh for home with a friend in his Bonanza. The field was barely marginal VFR and when we called for clearance, we were number 87 for the callback. Eventually, the weather cleared enough on the field for ATC to start flushing departures out VFR.

But a few miles east, it was low ceilings and light rain and we were solid IMC at 500 feet. We couldn't descend out it and climbing made no sense because the tops were probably well above 5000 feet, but I wasn't even sure of that. So we blundered along at 500 feet, hoping we would encounter a better idea before we encountered another airplane. I'm sure I have repressed how far we actually flew in these conditions, but I distinctly remember saying we were probably safe enough because no other fools would be down here in the clouds with us.

When we finally reached better weather and the vis improved, we saw an airplane off the left wing at less than a mile, paralleling our course. There were a couple of others in view ahead of us. Jeepers. After that, I stopped flying into OSH in other than reliable VMC. I'm not sure whether ADS-B would have been a benefit or not, but when looking at all those electronic targets, it's easy to forget that in all circumstances and especially in traffic as dense as that around AirVenture, not all the airplanes out there will be nicely plotted on your electronic gizmos.

It's a recipe for complacency. It also makes me wonder what AirVenture 2040 will be like, when the vaunted NextGen is in place and far more aircraft will be ADS-B equipped. My educated guess is that somewhere between 2020 and then, AirVenture traffic will choke the system to a standstill locally and the FAA will have to rush some sort of desperation patch into place. Not that I'm cynical or anything and not that you're reading it first here because people far more expert in the technology than I have such doubts about NextGen architecture.

The good news is that by Sunday afternoon, the weather cleared and there was the usual VFR mad rush into the field. Not a first for that, either. I didn't make it out to the runway to grade landings but plan to make it today.

Our coverage of AirVenture 2018 continues.