It was a typical early summer day in Central Texas, and a friend and I were going to grab a bite to eat at an airplane-local spot, Fredericksburg (T82), where there’s a great 1950s style diner that serves biscuit and gravy (don’t tell your AME) all day. The trip wound up offering a couple of interesting surprises, one of which you can probably guess if you glanced at the title of this piece.
VFR traps are almost always related to weather, and more often than not, to unanticipated weather. Of those surprises, the most common is otherwise benign weather that’s lower than forecast or lower than you hoped it would be despite the forecast.
On the day of our trip, I was watching the weather out of the corner of my eye, and there looked to be no surprises in store. The clouds were forecast to be low-ish VFR, with broken ceilings of around 2,000 AGL rising up to better than 5,000 feet by the time of our flight. One thing about the weather that never surprises me is when a cloud cover lifts more slowly than forecast. The weather folks are getting better and better at predicting the future, but when it comes to a cloud cover lifting, small variables in the condition, largely temperatures and stability, can mean big differences in how long a low layer hangs around. I wasn’t too worried, as we had options galore, including just driving into downtown San Marcos and grabbing a bite. Get-there-itis was not a factor.
As it turned out, the weather was lifting a good deal more slowly than we’d anticipated, but it was lifting sufficiently to allow us to go VFR. When you’re below 3,000 feet AGL, the rules for direction of flight when you’re in cruise don’t apply, so we could cruise at 2,000 feet westbound and still have plenty of clearance below the broken deck, knowing that as we flew west the ceiling would rise to up to 4,000 feet or so by the time we got to Fredericksburg.
One concern you always have when flying low are obstacles, and more and more that can mean RTTs, or, really tall towers! The tallest tower in the United States is a radio tower in Blanchard, North Dakota, that reaches to 2,063 feet (Unless otherwise noted, all tower heights mentioned are AGL). It is one of only three towers that top the 2,000 foot mark, though there are 58 U.S. towers that rise to 600 meters (1,967 feet) or taller.
The one that popped out at us while we were headed to Fredericksburg was one that we knew was there and could see on Garmin Pilot but still had a hard time seeing with naked eye. At 1,149 feet AGL and 3,049 feet MSL, it’s not a huge tower in comparison to the biggest of the big, but all that matters is that last foot if you hit it.
The point is, at our cruising altitude of 3,000 feet we were actually a little below the top of the tower that, if you draw a straight line from San Marcos to T82, is just to the right of course. It’s a well known and oft-discussed obstacle among local pilots.
So in this case, staying out of the cloud bases and giving ourselves plenty of room below the bases, as required by the FARs, put us in a position where we were having to dodge towers, with at least one of them actually above our cruising altitude.
When you’re flying IFR, it’s not an issue. Even direct-to routings will give you terrain (and obstacle) clearance. When you’re VFR, remember, even when you’re getting flight following, which we were, you’re still the one clearing yourself and assuring that the route is a good one. In our case, we knew where that tower was, and even though we had a hard time seeing it with the naked eye until we were within a couple of miles (remember guy wires, people), we knew where were in relationship to it the whole time. Apps rule.
There are other issues to contend with flying low to stay clear of clouds, including mountainous terrain and adverse weather that makes continuing toward your destination problematic and can even make doing a 180 a tricky strategy.
But when it comes to obstacle clearance, there’s really little excuse these days to be surprised by the sudden appearance of a tower. Flying low assumes an increased level of risk. That requires doing more homework and ensuring the path is safe.