Flying Through Hurricane Matthew
As I write this, the US Air Force Hurricane Hunters are flying their thirty-third mission into Hurricane Matthew off the coast of Florida. The mission requires the crew to fly their Lockheed WP-3D Orion directly through the storm, passing through the eye many times. As they fly they collect data which is crucial to the production of the life-saving hurricane forecasts.
What Do They Learn?
In the modern world, we have many sources for weather information including thousands of ground-based weather stations, radar, and satellites. Unfortunately, none of these sources can tell you the critical information you need to understand a hurricane: the air pressure and wind speed throughout its mass.
As the plane flies its prearranged flight path, it collects wind speed and air pressure information:
At prearranged points along the flight path, the plane drops Dropsondes. Each dropsonde slowly falls under a small parachute, collecting air pressure and wind speed information and reporting what it learns back to the aircraft.
A given dropsonde will report the temperature, pressure and wind information it gathers, generally visualized as a Skew-T plot:
All told, the flights (which are coordinated by the National Hurricane Center) provide a detailed image of the hurricane’s current status, which allows them to model its future path and strength.
How Safe Is It?
Very, it turns out.
Hurricanes are not particularly dangerous, simply because the wind is horizontal. While hurricane wind speeds can exceed 150 knots, planes flying in the Jet Stream commonly fly in even faster winds.
Planes travel with the wind, and for a pilot that wind speed often only becomes relevant when they are figuring out how long a flight will take, and when it comes time to takeoff or land.
So what is dangerous weather for aircraft? Thunderstorms. Thunderstorms have incredibly strong vertical winds which can change quickly and dramatically. The rapidly changing wind can easily overstress the airframe, leaving bits and pieces of plane spread over a mile long area. Thunderstorms are also a breeding ground for hail, lightning, and icing any of which can seriously damage an aircraft.
A hurricane, despite its strong horizontal winds, is otherwise a stable and predictable environment for an aircraft. Of course, the opposite is true if you’re on the ground, where horizontal winds can do incredible damage.
Who Was The First (Crazy) Person Who Decided To Try?
Like all great bad ideas, hurricane hunting began with a bet. During World War II British pilots teased Americans who were moving their AT-6 Texan aircraft to avoid an incoming hurricane. Not one to accept an insult, Colonel Joe Duckworth flew two separate missions directly through the storm to show off just how strong the Texan was.
Duckworth described the flight as “being tossed about like a stick in a dog’s mouth.”
Once it was clear it was possible, it was only a matter of time before weather forecasters realized the potential information which could be learned from these flights. In the modern world these flights remain a uniquely American phenomenon, no other country attempts them.
