WC-130J Hercules

The WC-130J is a C-130J transport configured with palletized weather instrumentation that collects weather data, and is capable of staying aloft almost 18 hours at an optimum cruise speed of more than 300 miles per hour. To fulfill this requirement, the aircraft is equipped with two external 1,400 gallon (5,320-liter) fuel tanks and an internal 1,800 gallon (6,480 liter) fuel tank.

The WC-130 provides vital tropical cyclone forecasting information. It penetrates tropical cyclones and hurricanes at altitudes ranging from 500 to 10,000 feet (151.7 to 3,033.3 meters) above the ocean surface depending upon the intensity of the storm. An average weather reconnaissance mission might last 11 hours and cover almost 3,500 miles while the crew collects and reports weather data. The WC-130J carries a minimal crew of five: pilot, co-pilot, navigator, aerial reconnaissance weather officer and weather reconnaissance loadmaster.

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.

The C-130J's Allison AE2100D3 engines generate 29 percent more thrust and increase fuel efficiency by 15 percent over the older models, while bringing the aircraft to a cruising altitude of 28,000 feet in 14 minutes. Standard C-130J "glass cockpit" avionics and computer software automate many tasks, allowing crewmembers to spend more time on the mission. Sensors mounted on the outside of WC-130Js provide real-time temperature, humidity, barometric pressure, radar-measured altitude, wind speed and direction. These are used to calculate a complete weather observation every 30 seconds.

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 and other sensing devices and is released from the aircraft around every 400 miles over water. 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 by satellite. This information is transmitted by satellite directly to the National Hurricane Center for input into the national weather data networks. Forecasters use the data to better predict the path of a storm or hurricane.

The WC-130J program was managed by the C-130J Development System Office. In September 1998 the C-130J Development System Office signed a contract with Lockheed Martin Aeronautical Systems, Marietta, Georgia to modify 6 C-130Js to the "W," or weather reconnaissance, configuration. This involved installing and integrating special avionics and weather sensors, as well as making structural modifications. The Development System Office later exercised contract options to modify an additional 4 C-130J aircraft. The contract to modify all 10 aircraft was valued at $62.9 million.

During development, 4 major issues confronted the WC-130J weather reconnaissance aircraft according to the Director, Director, Operational Test & Evaluation (DOT&E). These were that the radar could not perform the hurricane reconnaissance mission, continuous satellite communication had not been achieved, there was propeller delamination, and there was excessive vibration in the auxiliary crew member's station.

The low-power color radar was designed as a weather avoidance radar, but it had been installed in the WC-130J to perform the weather penetration mission. The radar did not support operational requirements for the weather mission. The program office developed a plan to correct this deficiency. Additional software modification tests were planned for late 2003 (storm season), but testing was not accomplished due to software deficiencies. Hardware modifications were to be tested approximately 26 months after the contract was awarded. Initial operational capability could be no sooner than FY06. Since the WC-130J could not perform its primary mission, the correction of the deficiency was critical. The secondary impact was that the 10 older WC-130H models that were performing the mission were already planned to be converted to aerial refueling tankers and transferred to Air Combat Command. That conversion could not occur until the WC-130J was fully operational. A proposed fix to the propeller delamination problem had been installed on test aircraft. Data was then collected by the Air Force Reserves. The fix had to be tested in a hurricane environment however.

The US Air Force took delivery of its first WC-130J aircraft on 12 October 1999. The aircraft was assigned to the Air Force Reserve Command's 53rd Weather Reconnaissance Squadron at Keesler Air Force Base, Mississippi. The 53rd Weather Reconnaissance Squadron, a component of the 403rd Wing, was the only unit in the Department of Defense flying the mission requiring the WC-130 type. Six other WC-130J aircraft were delivered to the base in 1999, and 3 more in 2000. In May 2007, the WC-130J were equipped with the Stepped-Frequency Microwave Radiometer, which continuously measured the surface winds and rainfall rates below the aircraft. The WC-130Js completely replaced the 53rd Weather Reconnaissance Squadron's fleet of 10 WC-130H-model aircraft by 2006.