It all started during World War II on a bet. Visiting British instrument students claimed their version of the North American T–6, called the Harvard, was better built than the American T–6 Texan. Army Air Corps pilot Joe Duckworth decided he could prove them wrong by flying his Texan from the base in Bryan, Texas, out over the Gulf of Mexico and into a hurricane with navigator Ralph O’Hair on board. The two survived the flight, and apparently hadn’t had enough because later that day Duckworth went again with a weather observer. The scientific potential of flying into hurricanes was seen almost immediately and, within a few years, the 53rd Weather Reconnaissance Squadron was born. The 53rd lives on today, having shed its training airplanes for the highly capable Lockheed
WC-130J Hercules. The unit’s mission is simple: fly through hurricanes and send back information that is used to warn citizens of approaching storms.
It’s drilled into us early and often that thunderstorms and their associated hazards are to be avoided at all cost. The Hurricane Hunters of the 53rd perform a mission that requires them to fly through intense thunderstorms on almost every flight. “The storm is really just inwardly spiraling bands of thunderstorms,” says Lt. Col. Mark Stevens, a navigator with the 53rd and a general aviation pilot. “In a traditional hurricane you’ll have four, five, or six of these bands. If you’re going to get to the middle, you’re going to go through these thunderstorms.” How is it that a relatively stock transport aircraft can fly safely into thunderstorms with severe turbulence, torrential rain, lightning, and strong wind shear? “The biggest thing we respect is maneuvering speed and turbulence penetration speed,” says Stevens. Because an airplane flying below maneuvering speed will stall before it sustains structural damage, Stevens and the crew take every possible precaution. “We respect the structural limitations of our aircraft, and always operate below VA,” he says. But turbulence isn’t the only hazard.
The mission. Although technically an Air Force Reserve unit, about half of the members of the 53rd are full-time civil servants, which allows them to operate the squadron on a daily basis and respond quickly to their unique mission. They are tasked to fly anywhere from the mid-Atlantic to 300 miles west of Hawaii. That big an area means multiple crews are often operating at the same time. Since most Atlantic hurricanes affect the Caribbean island nations and Central and South America, a number of crews, airplanes, and support personnel will stage out of St. Croix in the U.S. Virgin Islands to monitor these storms. As the storms move west, the operation is moved, and based out of Florida, Georgia, Texas, or Andrews Air Force Base in Maryland.
Once tasked with a mission by the National Hurricane Center in Miami, the mission preparation begins. Flight planning is done with a military-spec online tool, not unlike AOPA’s Internet Flight Planner. As the navigator, Stevens will prepare the plan, print out and gather charts, and prepare an IFR flight plan for the crew to review, and for the aircraft commander to file. From there it’s out to the airplane for what is often a 12-hour mission. This includes transit time to the storm, six hours of work inside and around the storm, and transit time back.
Typically the unit will fly one of two missions—an invest, or investigative mission, or a fix. On an invest, the crew flies out to an area of low pressure system that the meteorologists at the National Hurricane Center believe has the potential for further development. The crew will get readings that help determine if it is a tropical wave or a closed low. Closed lows are the precursor to tropical storms and hurricanes. It simply means the wind makes a complete circle. On these missions, the crew will fly only 500 to 1,500 feet above the surface of the ocean since storms are categorized and defined by surface winds. From this altitude the weather officer can observe the sea state, which is another indication of the storm’s strength.
Once a closed low has formed, the crew will be tasked to fly out to the system and get a position fix and other data every 12 hours. As the storm approaches land, that frequency increases to six hours, and then three hours. And, yes, that means they are flying into hurricanes at night.
Once on site at the storm, the crew will fly between 5,000 feet and 10,000 feet, and fly through the storm’s center four times each mission. For a fix mission, the object is to do just that—get a latitude, longitude, and pressure at the center of the storm, as well as temperature and general characteristics. Capt. Jonathan Brady, a weather officer in the unit, says that the visual eye seen on the satellite photos may not be the same as the center of low pressure at the surface. The weather officer helps the pilot hunt for the center by checking for when the wind abruptly switches direction. “It’s sort of like a VOR station passage,” Stevens says.
Other than finding the center, the weather officer gathers data throughout the flight. Using a SFMR, or Stepped Frequency Microwave Radiometer, the weather officer can get readings of surface wind direction and speed. They will also release dropsondes three times each pass—one on initial eyewall penetration, one in the center of the eyewall, and one on the opposite side. These devices are essentially a weather balloon in reverse. They fall to the ocean surface under a parachute, taking pressure, temperature, dew point, and wind readings all the way down. As Stevens puts it, “If the satellite is an X-ray picture, the airplane is a biopsy of the storm. We go through the storm, measure the intensity, and pinpoint the location.”
If the flight is successful (Stevens says the unit has a better than 99-percent mission effectiveness rate over decades of storm flying), the data is transmitted back to the hurricane center via satellite in close to real time, where it is placed into forecasting models. According to the National Hurricane Center, the work of the 53rd increases the accuracy of the forecast path by 30 percent. That may not seem like much, but when you consider it costs $1 million a mile to evacuate for a storm, the savings can be significant. Between that, and a better allocation of limited emergency and evacuation resources, the benefits are huge.
Washing machine. Stevens describes the feeling of being inside a hurricane as like a washing machine. There’s severe to extreme turbulence, torrential rain, and serious updrafts and downdrafts. “I’ve seen instances where we’ve had airplanes at idle power, that weigh 130,000 pounds, the pilots maintaining a pitch attitude to stay well below VA, going up 6,000 feet a minute,” he says.
The feeder bands that form the eyewall are usually the strongest part of the storm, and Stevens says they could encounter 6,000-feet-per-minute updrafts before crossing through the feeder band, only to be pushed down at 6,000 feet a minute on the opposite side. “Sometimes it can be a 45-degree crab just to fly straight, during the portions of the flight within about 45 miles of the eye,” he says.
Once they cross into the eye, things calm down for a minute. “The wind can drop from 110 knots to 90, 80, 70 as fast as you can say it,” Stevens says. If the eye is well-defined, the crew could potentially see the ocean and then a straight wall of clouds going up to 60,000 feet. The eye may be only five to 15 miles across for well-defined storms, or up to 50 miles or more for those not as strong.
Getting to the eye is one of the more dangerous parts of the flight, and the navigator and weather officer work hand in hand to make sure it’s done safely. The WC-130J has onboard weather radar that’s able to show extreme turbulence, which Brady says can even be set to flash for the worst conditions.
“As a navigator, the primary responsibility I have is monitoring and updating the crew via radar. We can detect wind shear, we can detect turbulence through Doppler sensing. So we don’t barrel straight into everything. We do some maneuvering around, especially the dangerous-looking portion of the storm,” Stevens says.
Unbelievably, there are no ops specs or guidelines for when a storm might be too severe to fly in to. “We’re not going to say we’re not going into that because it’s a category 5,” Brady says. According to Stevens, they’ve flown every storm since 1944. In fact, Stevens remembers only one storm where the crew called it off, but that was after they had made it through the eye and gathered the data. It was Hurricane Mitch, and they were flying off the coast of Nicaragua. Once the hurricane hit land, the mechanical turbulence from the mountains caused especially difficult conditions, even for the crew still flying over water. “The pilot said, ‘I think I’ve had about enough of this. What do you think?’” And with that they went home.
Although on the surface it may seem contrary to everything we know as pilots to fly into such awful weather, the crews of the 53rd do it safely thanks in part to a simple technique all pilots learn from nearly the beginning of pilot training: Maintain a pitch attitude and power setting to stay below maneuvering speed and the airplane will stay intact.
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