HURRICANE RECONNAISSANCE
Aerial weather reconnaissance is vitally important to the
forecasters of the National Hurricane Center. Reconnaissance
aircraft penetrate to the core of the storm and provide detailed
measurements of its wind field, as well as an accurate location
of the center: information that is usually not available from any
other source. The information helps the meteorologist determine
what is going on inside the storm as it actually happens.
Aircraft data are a vital part of the information the hurricane
specialists use in their forecasts of speed,intensity, and
direction of movement of the storm.
The National Hurricane Center is supported by specially modified
and equipped aircraft of the U.S. Air Force Reserve (AFRES) and
the National Oceanic and Atmospheric Administration's Aircraft
Operations Center (NOAA/AOC). AFRES' 53rd Weather Reconnaissance
Squadron,known as the "Hurricane Hunters" is based at Keesler Air
Force Base near Biloxi, Mississippi. The unit flies the Lockheed
WC-130 "Hercules," a four-engine turboprop aircraft which carries
a crew of six people and can stay aloft for up to fourteen hours.
NOAA flies Lockheed WP-3 "Orions", another four engine turboprop
which carries a crew consisting of from seven to seventeen
persons and can stay aloft for up to twelve hours. The NOAA/AOC
aircraft and crews which fly primarily research missions are
based at MacDill Air Force Base in Tampa, Florida. Both units can
be deployed as needed in the Atlantic, Caribbean, Gulf of Mexico
and the Central Pacific Ocean.
Meteorological information obtained from aerial reconnaissance
include winds, pressure, temperature, dew point temperature and
location of the storm center. A parachute borne weather sensor
dropped from the plane measures the storm characteristics below
the aircraft. Data from the storm environment is available almost
instantly with observations taken as often as every 30 seconds.
This information provides a detailed look at the structure of the
storm and a clear indication of its intensity.
Flying into a hurricane is a unique experience. Weather crew
members who have flown combat missions say that their feelings
before both types of missions were similar. There is a blend of
excitement and apprehension. Adding to the tension is the
knowledge that no two hurricanes are alike. Some are gentle while
others are like raging bulls. Preparations for flying into a
hurricane must be thorough. All crew members are highly trained
specialists. Loose objects are tied down or stowed away and crew
members wear seat belts and safety harnesses. Once the
meteorological equipment pinpoints the storm center, the crew
determines the easiest way to get inside. In a well developed
storm, this can be a difficult challenge. Winds at flight
level often exceed 100 miles per hour and the wall cloud
surrounding the center can be 10-15 miles thick. Rain often comes
in torrents,and updrafts and down drafts are usually strong and
frequent. Inside the eye, however, the conditions are much
different; many times the ocean is visible and there is blue sky
and sunshine above. The flight level winds are nearly calm. Often
the eye and wall cloud presents a stadium effect, like standing
in the center of a large football stadium.
Both the WC-130 "Hercules" and the WP-3 "Orion" operate most
efficiently at altitudes of 24,000 to 30,000 feet. Since most
storms occur some distance from the aircraft's home station the
crew usually flies to the storm at high altitudes to conserve
fuel. About 200 miles from the storm the aircraft descends to its
storm operating level. If the storm is in its infancy such as a
depression or tropical storm with winds less than 50 ,mph, the
crew operates as close to the surface of the sea as
possible--from 500 to 1500 feet. If the storm is more fully
developed, either a hurricane or a strong tropical storm, the
aircraft flies its pattern, including penetrations to the center,
at 10,000 feet altitude. A typical mission will last from 10-12
hours during which time the crew will penetrate to the center of
the storm anywhere from 3 to 6 times. When the mission is
completed, the aircraft will climb back to high altitude for the
trip home.
Aerial weather reconnaissance into one of nature's most
destructive forces is not without risk. In September 1955, a Navy
P2V and its crew of nine plus two Canadian newsmen were lost in
the Caribbean Sea while flying in Hurricane Janet. Three Air
Force aircraft have been lost flying in typhoons in the Pacific.
The job of coordinating the reconnaissance effort rests with a
small group of Air Force civilians assigned to the Hurricane
Center.This unit, under the Chief, Aerial Reconnaissance
Coordination, All Hurricanes (known by the acronym CARCAH) is
responsible for determining requirements and arranging for
supporting flights. Data relayed back to the Center by satellite
downlink is checked for accuracy by CARCAH and then transmitted
to the world-wide meteorological community through both military
and civilian communications circuits.
53rd WEATHER RECONNAISSANCE SQUADRON
HURRICANE HUNTERS
The 53rd Weather Reconnaissance Squadron located at Keesler Air
Force Base near Biloxi, Mississippi is a one-of-a-kind
organization--it is the only unit in the world flying weather
reconnaissance on a routine basis. The mission of the Hurricane
Hunters is to recruit,organize and train assigned personnel to
perform aerial surveillance of tropical storms and hurricanes in
the Atlantic, Caribbean, Gulf of Mexico and Central Pacific. The
unit also flies winter storm missions off both coasts of the
United States.
The 53rd WARS is authorized 20 aircrews. Each aircrew is made up
of six personnel: two pilots, a flight engineer, navigator,
weather officer and dropsonde operator.
To perform their mission, the Hurricane Haunters have ten WC-130
aircraft. These are C-130 Hercules which are specially-configured
with computerized meteorological data-gathering instruments.
HISTORY
The unit was activated on January 1, 1976, as the 815th Weather
Reconnaissance Squadron, Air Force Reserve, at Keesler AFB. Known
as the Storm Trackers, the unit's first hurricane mission was
June 9,1976, when it flew two penetrations into Hurricane Annette
off Western Mexico in the Eastern Pacific. In 1991, it became the
last Air Force organization flying weather missions. The unit was
renamed the 53rd Weather Reconnaissance Squadron "Hurricane
Hunters" on November 1, 1993, in honor of the active duty
organization of the same name that had flown the Atlantic
hurricane mission since the 1950's. The 53rd WARS continues a
proud weather reconnaissance tradition of service to the country
which began in 1944 after Admiral Halsey's fleet experienced two
disastrous encounters with typhoons in the Western Pacific.
RESEARCH AIRCRAFT
The National Oceanic and Atmospheric Administration (NOAA)
maintains two "flying laboratories" to support its oceanographic
and atmospheric research activities. The WP-3D Orions are
heavily instrumented and powered by four turbo-prop engines.
They have been in NOAA's service since 1975.
On the average, each research aircraft logs about 400 hours a
year, aiding scientists in better understanding hurricanes,
studying the ocean currents, and investigating the structures of
severe storms. The aircraft are also used for testing new
instrumentation and participating in a variety of other
scientific endeavors.
During the hurricane season, the P-3s help support the National
Hurricane center (NHC) in monitoring and forecasting tropical
storms and hurricanes. The aircraft penetrate these dangerous
storms to collect and transmit meteorological data critical to
the forecasts and warning issued by NHC forecasters.
AIRCRAFT SPECIFICATIONS AND PERFORMANCE DATA
Length: lll'2" True Air Speed: 325 kts
Height: 33'8" Wing Span: 99'7"
Engines: (4) T-56-A14 Max Range: 3,600 nm
Mission Time: 8.5 hrs @ low altitude
11.0 hurs @ high altitude
WC-130 WEATHER RECONNAISSANCE AIRCRAFT
AIRCRAFT - Cost: $22 Million new
- $2,500 per hour to operate
- Flying time is 14 hours depending on speed,
altitude and weight
- Uses 4-5,000 lbs of fuel or 670-830 gallons
of fuel per hour
- 35,000 ft maximum altitude
- Maximum speed is 32- knots
- Wing span is 132'7"
- Tail height is 38'6"
- Length 100'2"
- 25 passenger maximum
ENGINES - Allison T56-A-15 Truboprop, constant speed
- Develops 4,300 shaft horsepower
- Weight 4,200 lbs.
- RPM 13,820
- Cost $132,000 each
PROPELLERS - Weight 1,400 lbs each
- Cost $30,000 each
- Diameter is 13'6"
- Tip of blade travels at just under the speed
of sound
TIRES - Cost $600 new, $400 recapped, 90% used are
recapped
- Weight 350 lbs,
- Size 20" rim, 26 ply
METEOROLOGICAL PARAMETERS MEASURED:
- Precise geographical position of the flight-level storm
center and relative position of the surface center
- Center sea-level pressure determined by dropsonde or
extrapolation from within 1,500 ft of the sea surface
- Minimum pressure at 5,000 ft or 10,000 ft altitude
- Wind profile data for flight level
- Temperature profile at flight level
- Dew point profile at flight level
WEATHER RECONNAISSANCE --A PERSPECTIVE
On 27 July 1943, Major Joe Duckworth flew a propeller-driven,
single-engine North American AT-6 Texan trainer into the eye of a
tropical storm near Galveston, Texas. Major Duckworth flew into
the eye of the storm twice that day, once with a navigator and
again with a weather officer, in what are generally considered to
be the first airborne attempts to obtain storm data for use in
plotting the position of a tropical cyclone as it approached
land.Duckworth's pioneering efforts paved the way for further
flights into tropical cyclones.
By the late 1950's, over 100 aircraft were configured for a
variety of weather missions. As weather satellites were developed
and refined during the 1960's, they eventually replaced aircraft
for general reconnaissance duty because of their large viewing
area. While tropical cyclones can also be easily observed by
satellites, detailed information on their position and strength
can only be measured by an aircraft. As a result, what has
developed over the years is known as the United States Air Force
Tropical Cyclone Reconnaissance Mission. Today that mission is
proudly carried on by the Air Force Reserve.
The workhorse of the Air Force weather reconnaissance fleet has
been and continues to be the Lockheed WC-130 Hercules. The
aircraft in current use is the WC-130 which was adapted for the
weather reconnaissance role from earlier transport and rescue
versions. The aircraft is straight off the production line and
receives no further strengthening to fly the hurricane mission.
WC-l30's carry a basic crew of six: pilot, co-pilot, flight
engineer, navigator, aerial reconnaissance weather officer (ARWO),and dropsonde operator. The pilot who is the aircraft commanderand the co-pilot fly the plane. The navigator keeps track of theaircraft's position and movement. The flight engineer monitors the mechanical functioning of the aircraft. The ARWO observes and records meteorological data at flight level. The dropsonde operator collects and records vertical meteorological data from flight level to the surface of the ocean using a parachute borne instrument called the dropsonde.
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