Published February 12, 2013
The WC-130J Hercules is a high-wing, medium-range aircraft used in weather reconnaissance missions. This plane is a C-130J transport configured with palletized weather instrumentation for penetration of tropical disturbances and storms, hurricanes and winter storms to obtain data on movement, size and intensity. The WC-130J is the weather data collection platform for the 53rd Weather Reconnaissance Squadron.
The aircraft is capable of staying aloft almost 18 hours at an optimum cruise speed of more than 300 mph. An average weather reconnaissance mission lasts 11 hours and covers almost 3,500 miles. The crew collects and reports weather data as often as every minute.
The WC-130J carries a minimal crew of five: pilot, co-pilot, navigator, aerial reconnaissance weather officer and weather reconnaissance loadmaster. The crew and the aircraft are assigned to the 53rd WRS, an Air Force Reserve Command unit assigned to the 403rd Wing at Keesler Air Force Base, Miss. The 53rd WRS, known as the Hurricane Hunters, is responsible for hurricane reconnaissance missions in the Atlantic Ocean, the Caribbean Sea, the Gulf of Mexico and the eastern and central Pacific Ocean areas.
From the front of the cargo compartment, the Aerial Reconnaissance Weather Officer operates the computerized weather reconnaissance equipment and acts as flight director in the storm environment. The weather officer also evaluates other meteorological conditions such as turbulence, icing, visibility, cloud types and amounts, and ocean surface winds. The ARWO uses the equipment to determine the storm's center and analyze atmospheric conditions such as pressure, temperature, dew point and wind speed. This data is sent in real time via satellite link to the National Hurricane Center in Miami, FL.
In May 2007, the WC-130J was equipped with the Stepped-Frequency Microwave Radiometer, a state of the art instrument which continuously measures the surface winds and rainfall rates below the aircraft. This data is critical in mapping the surface wind environment below the aircraft and provides enhanced surface wind information to the National Hurricane Center.
Another critical piece of weather equipment on board the WC-130J is the dropsonde system. The GPS Dropsonde Windfinding System is a cylindrically-shaped instrument about 16 inches long and 3.5 inches in diameter and weighs approximately 2.5 pounds. The dropsonde is equipped with a high frequency radio. The instrument is dropped within the eye and eyewall of hurricanes and provides a direct reading of surface pressure. As the instrument descends to the sea surface, it measures and relays to the aircraft a vertical atmospheric profile of the temperature, humidity and barometric pressure and wind data. The dropsonde is slowed and stabilized by a small parachute. The Dropsonde System Operator receives, analyzes and encodes the data for transmission via satellite.
The WC-130J provides data vital to tropical cyclone forecasting. The WC-130J usually penetrates hurricanes at an altitude of approximately 10,000 feet to collect meteorological data in the vortex, or eye, of the storm. The aircraft normally flies a radius of about 105 miles from the vortex to collect detailed data about the structure of the tropical cyclone.
The information collected makes possible advance warning of hurricanes and increases the accuracy of hurricane predictions and warnings by as much as 20 percent. Collected data is relayed directly to the National Hurricane Center, in Miami, a Department of Commerce weather agency that tracks hurricanes and is responsible to provide warning services in the Atlantic and Pacific oceans.
Primary function: Weather Reconnaissance
Primary contractor: Lockheed-Martin
Power plant/manufacturer: Four Rolls-Royce AE 2100D3 turboprops
Horsepower: More than 4,700 horsepower each engine
Length: 97 feet, 9 inches (29.3 meters)
Height: 38 feet, 10 inches (11. 9 meters)
Wingspan: 132 feet, 7 inches (39.7 meters)
Speed: 417 mph/362 ktas (Mach 0.59) at 22,000 feet (6,706 meters)
Ceiling: 28,000 feet (8,615 meters) with 42,000 pounds (19,090 kilograms) payload
Maximum Range with 35,000 pound payload: 1,841 miles (1,600 nautical miles)
Maximum takeoff weight: 155,000 pounds (69,750 kilograms)
Crew: Five (pilot, co-pilot, a navigator, aerial reconnaissance weather officer, and weather reconnaissance loadmaster)