Lockheed WC-130 - Variants

Variants

The Lockheed C-130 has been operated as a Weather Reconnaissance aircraft in the following sub-types:

Lockheed WC-130A

Three aircraft were converted to WC-130A standard for use by the 54th Weather Reconnaissance Squadron, (56-519, 56-522 and 56-537), flying from Guam and Udorn RTAFB in Thailand. All three were returned back to C-130A standard, with 56-519 returning to Vietnam where it was captured at Tan Son Nhut Air Base on the surrender of the South to the Viet Cong, remaining there to this day.

Lockheed-Martin WC-130J

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 53d Weather Reconnaissance Squadron, an Air Force Reserve Command unit assigned to the 403rd Wing at Keesler Air Force Base, MS. The 53rd WRS, known as the Hurricane Hunters, is responsible for the reconnaissance mission in the Atlantic Ocean, Caribbean Sea, Gulf of Mexico, and Eastern and Central Pacific Ocean areas.

The aircraft is capable of staying aloft almost 18 hours at an optimum cruise speed of more than 300 mph (480 km/h). An average weather reconnaissance mission lasts 11 hours and covers almost 3,500 miles (5,600 km). The crew collects and reports weather data as often as every minute.

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.

A 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 (41 cm) long and 3.5 inches (8.9 cm) in diameter and weighs approximately 2.5 pounds (1.1 kg). The dropsonde is equipped with a high frequency radio and other sensing devices and is released from the aircraft about every 400 miles (640 km) 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.

Beginning in May 2007, the WC-130J will be equipped with the Stepped-Frequency Microwave Radiometer, which continuously measures the surface winds and rainfall rates below the aircraft.

The WC-130J provides data vital to tropical cyclone forecasting. The WC-130J usually penetrates hurricanes at an altitude of approximately 10,000 feet (3,000 m) to collect meteorological data in the vortex, or eye, of the storm. The aircraft normally flies a radius of about 100 miles (160 km) 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 30%. Collected data are relayed directly to the National Hurricane Center, in Miami, Fla., a Department of Commerce weather agency that tracks hurricanes and provides warning service in the Atlantic area.