When we fly we are accustomed to scanning the ground for obstructions like building cranes, towers, buildings, and rising terrain — but what about those obstructions above our altitude?
WHEN SNOOPY’S AT THE WHEEL
I once flew past, under, and around, the “MetLife” blimp — you know the one that looks like Snoopy is driving in the front. We waved at the airship pilots; it was a lot of fun. But flying around lighter-than-air aircraft should be done with extreme caution because there are several hidden dangers.
Ground Attachment: I’ve included the chart illustrations of Restricted Airspace around tethered balloons. These are Figures 1, 2, and 3.
WHAT IT MEANS
Inside these circular Restricted Airspace areas an unmanned balloons that are hooked — with thick cable — to a reel. The reel can let out up to 15,000 feet of cable allowing the balloon to rise into the sky to an altitude of about three miles. That’s quite a kite! The exact duties of these balloons are classified … but look at their proximity to our national borders. Figure 1 (above) is located in New Mexico on the U.S. and Mexican boarder. Figures 2 and 3 (below, shown from a WAC chart) are in Florida. Minimum standard equipment includes downward-looking radar to better interdict unauthorized inbound aircraft.
WHY IT MATTERS
The Restricted Areas are circular which roughly illustrates the radius of the cable. The balloon could be flying anywhere inside that circle depending on the wind. If you were to see one of the balloons you might mistake them for free flying aircraft and think there would be no problem flying under them — especially since they are so high. The balloon is easy to see; the cable underneath is not. Both the cable and the balloon are “unmarked.”
Danger: An even greater hazard would be present if the balloon itself was up in the clouds or above a cloud layer. In that case, the cable would appear to be standing up on it’s own, but you’d probably only see that right before you hit it. It would be hard or impossible to see until it was too late.
The possible heights of these balloons are also indicated by Maximum Elevation Figures (MEF) on the chart examples. The Latitude and Longitude lines form boxes all across the chart. In every box there is an MEF shown with a larger bold number that is the thousands of feet and a smaller raised number, which is the hundreds of feet. Figure 3 (above) depicts the MEF next to the balloon with a larger 15 and a smaller 2. This means that within that chart box the highest known feature including terrain and/or obstructions is 15,200 feet — in this case the obstruction is the unmanned balloon. In other words, an area of totally flat land can have an MEF thousands of feet above the ground.
The balloons in these example Restricted Areas are known hazards, but there can be wandering balloon hazards as well. Unmanned, free-flying weather balloons are present in the sky and could be anywhere. These balloons often trail a wire antenna and / or an instrument package underneath. If you see one of these balloons — do *NOT* fly under it! Report its position to an air traffic controller or Flight Service Station for the benefit and safety of other pilots.
BOTTOM LINE: Pilots fly in a three-dimensional space — not in lanes like cars on the freeway. We must look down, out, and up for obstructions. And we must always be wary of the things we can not see.