You’re Not Alone Down There
The fatal accident involving two employees of Icon Aircraft in 2017 should serve as a wakeup call for the risks of flying low. The pilot, a high-time test pilot with tons of hours and a strong knowledge of the terrain, chose the wrong canyon to fly into at low altitude. The one selected had no outlet, and by the time he realized it, there was no escape. Flying low carries risk, and flying around high terrain carries even greater risk, far greater.
It’s not just terrain. Tall towers are an ever-present hazard when flying low, and not all of them are charted; new ones crop up all the time. GPS alerting may not help much because you’re already operating in a continuous terrain-caution condition. The solution is to stay high enough to avoid all but the most unlikely super-tall obstructions by planning in advance. Watch for the large minimum-clearance altitudes on the sectional chart, which change with every lat-long grid, and when you see that number increase, take action. The larger obstruction symbol on the chart is only used when the tower pokes above 999 feet AGL; a 950-foot tower gets the smaller symbol, but it’ll kill you just as dead if you hit it.
In addition, avoid flying in the bottom of narrow valleys and canyons; stay at ridge level or above. There are often powerlines strung across the valleys that sag quite low between the supporting structures, so make sure you have clearance above the poles and towers.
Remember to be considerate of the effect of the noise you’re making. You may be insulated by the speed of your passage and your noise-canceling ANR headsets, but people under your flight path are not. Rattling windows as you pass by is not a friendly gesture. If you have a constant-speed propeller, dial it back to a low-rpm cruise setting. Most of the annoying noise impact from a light airplane comes from the propeller tips stirring up the air at transonic speed. The fun of flying low is enhanced by reducing airspeed for sightseeing. High-performance, heavy-horsepower airplanes are not suited for such cruising; flying at 3 miles per minute turns the landscape into a blur, so you’ll probably want to stay above 3,000 feet AGL if flying such an airplane.
And should you feel the urge to take a photo or two, don’t do it at low altitude, where flying the plane deserves your full attention.
Knowing how to manage the risks and challenges of low-level flight is a useful tool for your bag of flying skills, but it’s one that can’t be taken lightly.