Editing Lockheed WC-130 (section)

== Variants and operational history ==
The Lockheed C-130 has been operated as a Weather Reconnaissance aircraft in the following sub-types:

===WC-130B (1962–1973)===
Five new C-130Bs<ref group=n>The first group of B-models were AF serial numbers 62-3492 through -3496.</ref> factory-configured for air sampling were delivered to the [[55th Space Weather Squadron|55th Weather Reconnaissance Squadron]] at [[McClellan Air Force Base]], California, in 1962. After operational testing and evaluation, three were distributed to the 54th, 56th, and 57th WRS and the 55th deployed one of its remaining two to [[Eielson Air Force Base]], Alaska. In 1965 all had [[dropsonde]] systems<ref group=n>The system then in use consisted of the AN/AMR-1 Radiosonde Receptor manufactured by Landers, Frary and Clark, and the Bendix AN/AMT-6 dropsonde.</ref> installed at the [[Warner Robins Air Force Base|Warner Robins Air Materiel Area]] (WRAMA) and were transferred to the 53rd WRS at [[Ramey Air Force Base]], Puerto Rico, for use in the Hurricane Hunter mission. The first of thousands of such missions for the just-designated WC-130 was flown on 27 August 1965 into the eye of [[Hurricane Betsy]], the most destructive hurricane in recorded history to that time.{{sfn|Fuller|1990|p=355}}

In the aftermath of [[Hurricane Camille]] in August 1969 and the simultaneous shutdown of the WB-47 program, funds were appropriated to fund Project ''Seek Cloud'', an upgrade of tropical storm reconnaissance capability by an increase in C-130 platforms and an upgrade in meteorological equipment. 12 additional C-130B transports<ref group=n>The second batch of veteran C-130Bs acquired were s/n's 58-0725, -0726, -0729, 0-731, -0733, -0734, -0740, -0741, -0742, -0747, -0752, and -0758.</ref>  were obtained from [[Pacific Air Forces]] and modified in 1970–1971 with the new equipment suite.<ref group=n>The ''Seek Cloud'' suite consisted of an AN/APN-42 Radar Altimeter, AN/AMQ-28 Rosemount Total Temperature System, and AN/AMQ-19 Dropsonde receiver and control panel previously mounted in retired [[Boeing B-47 Stratojet|WB-47]]s; an AN/AMQ-29 Dropsonde Data Recording System; a Hewlett-Packard 9100B Desktop Programmable Calculator; an AN/AMQ-34 Cambridge Optical Dewpoint Hygrometer; a Barnes Engineering PRT-5 Infrared Sea-Surface Temperature System; three strip chart recorders (for recording wind speed and direction data, ambient dew point, sea-surface temperature, pressure altitude and radar altitude); and a AN/AMQ-31 Dropsonde Dispenser and AN/AMT-13 Radiosonde. All but the dropsonde dispenser were installed with their controllers in a new console on the flight deck.</ref>  One was soon transferred to the [[National Oceanic and Atmospheric Administration]] (NOAA)<ref group=n>58-0731 was re-numbered with civil registration N8037 and nicknamed ''NOAA's Ark''. It served as a hurricane research aircraft from 1970 to 1981.</ref> but the other 11 went into military service, three to the 54th to replace the WC-130As and the rest to the 53rd, which had transferred four of its five original B-models to other squadrons after receiving ''Seek Cloud'' retrofits. Efforts to develop forward-looking and side-looking weather radars were unsuccessful. The second batch of C-130Bs were in service only a few years before all were de-modified and turned over to the reserve forces.

The WC-130Bs were powered by four [[Allison T56|Allison T56-A-7A]] [[turboprop]] engines rated at {{convert|4,050|shp|kW}}, had a cruising speed of {{convert|350|knot|mph km/h}}, a radius of action of {{convert|1,200|miles|nmi km}} with a payload of {{convert|25,000|lb}}, and a service ceiling of {{convert|30,000|feet|m|0}}.{{sfn|Fuller|1990|p=355}}

===WC-130E (1965–1993)===
In 1965 the Air Force procured six E-model variants to replace six [[Boeing B-47 Stratojet|WB-47Es]] in the [[54th Weather Reconnaissance Squadron]] at [[Anderson Air Force Base]], [[Guam]].<ref>Fuller (1990), p. 355</ref> Three veteran airlifters were transferred from the [[Tactical Air Command]] (TAC) and three obtained new.<ref group=n>The six E-models were serial numbers 61-2360, 61-2365, 61-2366 and 64-0552 through -0554.</ref> All were modified with the AMT-1 dropsonde system and assigned to the 54th WRS, where they remained until 1972. From then to 1987, when they were assigned permanently to the 53d WRS, the E-models were assigned to the operational demands of all the operational weather reconnaissance squadrons. In 1989 they were upgraded with the Improved Weather Reconnaissance System ("I-Wars") utilizing the [[Omega (navigation system)|Omega Navigation System]]<ref group=n>"I-Wars" consists of three semi-independent sub-systems: the Atmospheric Distributed Data System (ADDS) which records and computes flight level meteorological data from various angle-of-attack probes, the radar altimeter, the pressure altimeter, ambient temperature and dewpoint sensors, and navigation data; the Dropsonde Windfinding System (DWS) which processes temperature, pressure, humidity, wind speed and direction data received from a dropsonde; and the Satellite Communication system (SATCOM). The ADDS generates measurements in the horizontal aspect ("horizontal data"), the DWS in the vertical ("vertical data"), and the SATCOM provides immediate direct transfer of the data to the user.</ref> previously installed in WC-130H model and remained in regular operational service until retired in 1993.

===WC-130A (1967–1970)===
Three C-130A transports<ref group=n>The three A-models were serial numbers 56-519, 56-522 and 56-537</ref> were obtained from TAC in 1966 during the [[Vietnam War]] to conduct [[Operation Popeye]], a rain-making operation in Southeast Asia. In early 1967 they were modified for an additional weather reconnaissance mission by installation of the AMT-1 dropsonde system. Two were based for the dual missions on a rotational basis at [[Udorn Royal Thai Air Force Base]], [[Thailand]], with a third at Anderson AFB for maintenance and crew changes. Missions were flown by crews of the 54th WRS and included [[Synoptic scale meteorology|synoptic weather reconnaissance]] to all areas of SEA. All three reverted to C-130A standard in 1971 after their replacement by upgraded models.<ref group=n>56-519 was given to the [[Republic of Vietnam Air Force|South Vietnamese air force]] and was captured at [[Tan Son Nhut Air Base]] by the North Vietnamese Army in 1975.</ref>

===WC-130H (1973–2005)===
[[File:Lockheed WC-130H Hercules (L-382), USA - Air Force AN1263353.jpg|thumb|right|WC-130H Hercules in flight]]
With the drawdown of U.S. participation in the war in Southeast Asia, a number of extended-range [[Lockheed MC-130#MC-130P Combat Shadow|HC-130H CROWN airborne controllers]] assigned to the [[Air Rescue Service|Aerospace Rescue and Recovery Service]] (a sister agency of the Air Weather Service in the [[Military Airlift Command]]) became excess because of budgetary reductions. With Hurricane Camille still fresh in the minds of Congress and the American public and retention of the AWS flying mission still strong in MAC Headquarters, AWS proposed to Headquarters Air Force in March 1972 that its 16 WC-130Bs be replaced by a like number of the available HC-130Hs. The request was approved in December 1972 but altered a month later. AWS was ordered to retain three of the Bs and could give up the other 13 in return for 11 HC-130Hs. $4.5 million was budgeted for WRAMA to transfer the ''Seek Cloud'' equipment from the Bs to the newer Hs, and the changeover occurred between June 1973 and July 1974.<ref name="fuller357">Fuller (1990), p. 357</ref> Four additional HC-130Hs were converted in 1975.

A total of 15 HC-130H rescue Hercules were eventually modified with ''Seek Cloud'' equipment and designated WC-130H,<ref group=n>These were all built as standard C-130E transports and reconfigured as HC-130H. Their serial numbers were 64-14861 and -14866; and 65-0963 through -0969, and -0972, -0976, -0977, -0980, -0984, and -0985.</ref> replacing all 16 WC-130Bs in the weather reconnaissance squadrons. The WC-130H was equipped with the more powerful [[Allison T56|Allison T56-A-15 turboprop engines]] rated at {{convert|4,910|shp|kW}} and had wing-mounted fuel tanks that provided an additional {{convert|2,720|usgal|impgal L}} of fuel, extending the WC-130H's radius of action at maximum cruise speed ({{convert|230|kn|mph km/h}} (KIAS), {{convert|350|kn|mph km/h}} (KTAS)) to {{convert|2,250|nmi|mi km}}.<ref name="fuller357"/>

A contract was awarded [[Tracor|Tracor Aerospace]] on 29 September 1987 to build and install 20 IWRS suites but two days later the 54th WRS was inactivated,<ref group=n>Manned weather reconnaissance for the second time faced a campaign to put it out of business to gain its funding, this time from supporters of the Defense Meteorological Satellite Program (DMSP) and its [[Television Infrared Observation Satellite|TIROS]] weather satellites at Headquarters AF and in the AWS. A "selective" tropical storm reconnaissance program was instituted in the Western Pacific in 1971 after TIROS was introduced, reducing the number of sorties flown and their associated costs, while the U.S. Navy had withdrawn from the manned weather reconnaissance business entirely in 1975. As a consequence, the [[Joint Typhoon Warning Center]] had incrementally reduced its reliance on WC-130 data until by 1986, although unquestionably more reliable than that from the satellites, it nevertheless made up less than 10% of the data used by JTWC to plot typhoons. The 53d WRS at Keesler was also a target, but it still had strong "[[pork barrel]]" support in Congress for its continuation that the Guam-based unit did not have. (Fuller 363–364, 370)</ref> leaving only ten WC-130s in service, seven with the 53d WRS and three in the Air Force Reserve.<ref name="fuller357"/> Even so, the IWRS system went operational in the WC-130H in 1988 and remains standard equipment.<ref group=n>In 1998 the original Omega Navigation Equipment for the DWS was replaced by the GPS-based Airborne Vertical Atmospheric Profiling System (AVAPS).</ref>

Manned weather reconnaissance continued to be reduced when AWS finally divested itself of its flying mission in 1991 by inactivating the 53d WRS and transferring both the mission and its few remaining aircraft assets to the [[Air Force Reserve Command]] (AFRC). But the devastation wrought by [[Hurricane Andrew]] in 1992 again demonstrated the need for "hurricane hunting" and state-of-the-art equipment to accomplish it, and the 53d was resurrected as a full-time unit of AFRC in 1993. The WC-130s were transferred back to it but the H-models were showing their age and between 1999 and 2005 all were replaced by the new, technologically-advanced J-variant.

===WC-130J (1999–present)===
[[File:Lockheed Martin WC-130J.jpg|thumb|WC-130J on the ramp at Dobbins Air Reserve Base during [[Hurricane Katrina]], 2005. A second WC-130J is landing in the background. The 53d WRS was displaced by severe storm damage to its base at Keesler AFB, Mississippi.]]
The WC-130J was the first variant obtained new from the factory since 1965. Ten were procured<ref group=n>AF s/n 96-5300 through −5302, 97–5303 through −5306, 98–5307 and −5308, and 99-5309.</ref> and assigned to the 53d WRS, now the only manned weather reconnaissance unit in the Department of Defense. The new model encountered teething problems<ref group=n>These were primarily damage to its [[composite material]] 6-bladed propellers from hail and ice and a lack of sensitivity in its color radar images.</ref> that delayed its Initial Operational Capability until just before the [[2005 Atlantic hurricane season]]. Conversion of the [[Lockheed Martin C-130J Super Hercules]] greatly enhanced the capability and safety of the WC-130 in its penetration of tropical cyclones on critical "fix" missions.
 
The WC-130J carries a minimum crew of five: pilot/aircraft commander, co-pilot, [[combat systems officer]], aerial reconnaissance weather officer and weather reconnaissance loadmaster. The 53d WRS maintains twenty air crews (ten full-time and ten part-time) to meet its capabilities obligations in support of requirements for the National Hurricane Operations Plan of five sorties per day from Keesler AFB and two from deployed locations. Weather data instrumentation and the dropsonde delivery and recording systems are mounted in the aircraft on removable pallets at the front end of the cargo compartment,<ref group=n>The ARWO station is mounted on the port side facing aft and the dropsonde operator's position on the starboard facing forward.</ref> giving the aircraft a standard cargo mission capability also.

The aircraft is not equipped for [[aerial refueling]], but with wing-mounted auxiliary fuel tanks is capable of staying aloft almost 18 hours at an optimum cruise speed of more than {{convert|300|mph|kn km/h|abbr=on}}. An average weather reconnaissance mission lasts 11 hours and covers almost {{convert|3500|mi|nmi km}}. The crew collects and reports weather data as often as every minute.

The Aerial Reconnaissance Weather Officer operates the computerized weather reconnaissance equipment, generates the "horizontal data" measurements (also known as "Recco"), and acts as flight director inside 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 to create a Vortex Data Message sent to the National Hurricane Center.

A critical piece of weather equipment on board the WC-130J is the GPS Dropsonde Windfinding System, a cylindrically-shaped instrument about {{convert|16|in|cm}} long and {{convert|3.5|in|cm}} in diameter and weighing approximately {{convert|2.5|lb}}. The dropsonde is equipped with a high frequency radio and other sensing devices and is released from the aircraft 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. Through use of the Advanced Vertical Atmospheric Profiling System (AVAPS),<ref group=n>AVAPS is a self-contained system installed in two standard 19-inch racks that records current atmospheric conditions vertically below the WC-130J aircraft as a deployed sonde falls to the surface. AVAPS consists of expendable sondes, a Dropsonde Telemetry Chassis, high power computer, and a color monitor.</ref> the Dropsonde System Operator generates the "vertical data" (also referred to as "Drops") needed by the NHC, receiving, analyzing and encoding the data for transmission by satellite.

Between May 2007 and February 2008, all ten WC-130J were equipped with the Stepped-Frequency Microwave Radiometer (SFMR or "Smurf"), which continuously measures the surface winds and rainfall rates below the aircraft, mounted in a radome on the right wing outboard of the number four engine.

The WC-130J provides data vital to tropical cyclone forecasting. The WC-130J usually penetrates hurricanes at an altitude of approximately {{convert|10000|ft}} to collect meteorological data in the vortex, or eye, of the storm. The aircraft normally flies a radius of about {{convert|100|mi|nmi 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.