One of the most unusual missions presently assigned to a U. S. Navy unit is that being carried out by Airborne Early Warning Squadron Four, otherwise known as the Navy’s “Hurricane Hunters.” The prime mission of this Navy squadron is to seek out, track, and penetrate the worst of nature’s weather phenomena—hurricanes.
Tropical cyclones, which are called hurricanes in the West Indies and typhoons in the Pacific and Far East, are considered by meteorologists to be the most intense of all general storms. It is true that a tropical cyclone is exceeded in localized violence by a tornado; however, since tropical storms or cyclones cover an area several times greater than tornadoes, travel much greater distances, and last for longer periods of time, their total destructive capacity is much greater than that of tornadoes. Since man first began recording the damage wreaked by tropical cyclones in the Western Hemisphere, property damage has amounted to billions of dollars and loss of life well into the thousands. Operating as a unit of the Joint Hurricane Warning Service, AEWRON Four patrols the Gulf of Mexico and the Caribbean Sea from early June until late November searching for these destructive tropical storms.
From the weatherman’s point of view, a hurricane in the Northern Hemisphere is a strong, counter-clockwise circulation of winds in excess of 75 miles-per-hour revolving about a central low pressure area and containing strong ascending currents. Air rushes into the churning mass of weather at low levels and from all sides with great force. This action forms the high, heavy cumulo-nimbus cloud masses characteristic of the tropical storm. Such extreme convergence and ascension of the air around the center of the tropical cyclone cause the high winds and intense pressure gradient, while the energy is basically derived from the release of heat from rapid condensation of water vapor.
Fundamentally, we can consider this type of storm as a huge parcel of circulating, ascending air expending tremendous destructive energy over an area about 200 miles in diameter. Of course, storms vary greatly in the amount of area they cover at given times in their development. Normally, their forward rate of movement over the water is between 10 and 20 miles-per-hour, but storms have reached speeds as high as 50 miles-per-hour in temperate latitudes.
The season for tropical cyclones extends from May through December in the Northern Hemisphere. The frequency of storms during this period varies greatly from month to month and from year to year. As an average, however, we can expect about eight tropical storms a year, of which five will grow into full-blown hurricanes. The variations in frequencies with which these storms occur are best realized when we see that as few as two, and as high as 21, have developed over the same periods in past seasons.
After years of dealing with the aftermaths of these tropical waves of destruction, the U. S. government recognized the need for some type of positive action to protect the public. Since there were no methods of controlling or dissipating the storms themselves, the only course of action open was early warning.
To provide such warning, the Miami Joint Hurricane Central was established in 1943. The organization was composed of units of the Navy, Army, and Weather Bureau. Its purpose was to gather weather information from island stations, ships at sea, commercial aircraft, and military aerial reconnaissance units, and to evaluate such information for prediction of tropical storm development and movement.
Prior to the establishment of the Miami Joint Hurricane Central, the U. S. Weather Bureau had been forced to rely on reports from whatever ships, planes, or weather stations happened to be located in the storm area. Needless to say, at the first indication of the possibility of a storm at sea, ships and aircraft altered course away from the danger areas, and information on the state and progress of the storm became extremely spotty. More often than not, reports reaching the Weather Bureau were so infrequent and widely scattered as to be of little use to forecasters. With the inception of military aerial reconnaissance however, the Miami Joint Weather Central had the capability of keeping close watch on tropical storms.
The Navy began fulfilling its function in the newly formed system by calling upon various naval aircraft squadrons in the Gulf of Mexico and Caribbean areas for storm reconnaissance’. No one squadron was assigned the task as a primary mission. The squadrons involved operated on a request basis for flights. It soon became apparent that such piecemeal activity could not supply the continual flow of precise information needed for accurate forecasting.
Consequently, in 1945 Navy Patrol Bomber Squadron One One Four operating out of the Naval Air Station Miami, Florida, was designated as the Navy’s first hurricane reconnaissance squadron. The plane selected for use was the four-engine, land-based Privateer. It was the Navy’s intention to make this squadron a specialized unit, in a ready status, capable of carrying out all types of weather reconnaissance.
The plan was successful, and at the end of its first season of storm tracking Patrol Bomber Squadron One One Four was re-designated as Weather Squadron Three. Then, at the end of its second season in weather reconnaissance, the Navy again changed its designation, this time to Meteorological Squadron Three.
By 1947, the slim base of knowledge on which aerial hurricane reconnaissance had begun was rapidly expanding. Lessons had been learned the hard way. Pilots were becoming more experienced and sure of themselves in storm penetration and weather personnel more knowledgeable in their special field of tropical meteorology. The hurricane service began to walk after a period of crawling.
In conjunction with Developmental Squadron Four based at the Naval Air Station, Quonset Point, Rhode Island, Meteorological Squadron Three entered the field of radar reconnaissance. Using radar-equipped B-17 Flying Fortresses the pilots and crews of Developmental Squadron Four proved the practicality of radar tracking of hurricanes and obtained the first night fixes on a tropical storm. Previous to this, night aerial hurricane reconnaissance had been so dangerous that it was considered almost impossible as a routine maneuver. Now another gap in the early warning system was closed, and a whole new area of study was opened to hurricane research.
Paralleling the development of radar tracking techniques was the improvement in basic visual hurricane flight techniques by the pilots of Meteorological Squadron Three. They had completed the development work on a “low-level penetration” technique that had started in 1944. After being thoroughly tested and proven in numerous storm flights it was no longer considered an unusual flight pattern.
The “low-level penetration” of a hurricane is basically just what the name implies: a low-level approach to the storm at 300 to 800 feet off the water, keeping the surface wind broad on the port wing so that the aircraft is always headed in towards the “eye” or center of the hurricane. There is naturally a great deal of heavy turbulence, intermittent instrument flight in very heavy rain squalls, and great strain on the pilot while flying so close to the water under the worst kind of flight conditions. But experience proved that it was a practical approach and provided the maximum amount of required surface weather data.
In 1949, Meteorological Squadron Three underwent another face-lifting operation. It was now to be called Patrol Squadron Twenty-Three.
For two more storm seasons Patrol Squadron Twenty-Three hunted hurricanes. Then in 1952, the squadron moved from Miami, Florida, to Brunswick, Maine. Its weather duties were assumed by Weather Squadron Two—a newly formed unit whose nucleus was experienced weather personnel from Patrol Squadron Twenty-Three. Immediately after the storm season of 1952, however, Weather Squadron Two was re-designated as Airborne Early Warning Squadron Four and its home base shifted to the Naval Air Station, Jacksonville, Florida. Since that time AEWRON Four has remained as the Navy’s Hurricane Hunters.
Throughout the period from 1944 to 1953 the Privateer had continued to be the accepted weather reconnaissance aircraft, but in 1953 AEWRON Four began shifting flight operations to the P2V Neptune, a twin-engine patrol bomber. The planes sent to AEWRON Four were especially configured for weather reconnaissance flight. Later models of this aircraft were also equipped with jet engines in addition to the standard reciprocating engines.
Further interest in improving the radar capability of the squadron resulted in experimentation with the WV-1 Constellation-type aircraft for storm flying in 1954. Following a full year of evaluation, further use of the Constellation was given the blessings of the pilots and weathermen of AEWRON Four. The squadron began to receive models of the weather-configured WV-3 Super Constellation for the 1955 hurricane season. The acid tests of the Constellation’s suitability for sustained weather reconnaissance flights were underway.
The Super Constellation came through with flying colors. It successfully completed its first full-fledged recon flight on hurricane Diane and then later made a radar penetration into the eye of lone. Hurricane hunting had moved into the electronic stage.
It took time, however, for AEWRON Four to shift its operations to the Lockheed Super Constellation exclusively. From 1955 until 1957 AEWRON Four operated both the P2V Neptune and the WV-3 Super Constellation. The Neptune performed the daytime low-level reconnaissance flights. The Super Constellation was used for night radar tracking. By now, night tracking and penetration of hurricanes was routine procedure for the Hurricane Hunters.
It would only be fair to add at this point that many pilots of AEWRON Four still were hesitant about flying a plane the size of the Super Constellation into tropical storms, particularly at low levels. But as their experience and familiarity with the plane increased, they began to recognize it as the more ideal aircraft for the job at hand, especially when it was proven that with proper flight techniques the Constellation could be used for low-level penetrations. Furthermore, it increased the weather reconnaissance potential of the squadron tremendously. With one sweep of its powerful radars the Constellation could scan an area greater than 200,000 square miles. One reconnaissance flight could provide information on an area encompassing 1,500,000 square miles.
To collect and correlate such a vast amount of information for dissemination from the aircraft and to keep the plane aloft for twelve to fifteen hours required a change in AEWRON Four’s flight crew assignments. Whereas the P2V had carried a crew of nine, the Super Constellation required a crew of approximately 24 officers and men to carry out a storm flight properly. For special missions the crew complement ran as high as 29 crewmen.
Basically, the squadron used a flight crew that was, and still is, broken down into three groups—a basic flight crew, a weather team, and a radar team. A basic flight crew consists of a plane commander, a co-pilot, two relief co-pilot navigators, three flight engineers, two radiomen, two electricians, and a flight metalsmith. A weather team will usually be made up of a weather officer, two weather specialists, and a photographer. A radar team will have aboard the aircraft a radar control officer, an assistant radar control officer, four radar plotters or specialists, and two electronics specialists.
The plane commander is the officer in charge of the flight. The lives of the crew are in his hands. He must not only be an experienced and competent pilot, but in addition must be a “weatherman” in his own right. He must have a practical, working knowledge of tropical storm phenomena in order to anticipate flight hazards in hurricanes and to deal with them properly and promptly. Also, his knowledge of radar and air control procedures must be such as to enable him to evaluate and use the information being passed to him by the radar team.
The weather officer is a trained meteorologist whose specialty is tropical weather phenomena. He is usually a graduate of the Aerological Engineering Course given at the Navy Postgraduate School in Monterey, California. He is responsible for the collection, interpretation, and transmission of weather information to the Joint Hurricane Warning Center.
The radar control officer supplements the data obtained by the weather officer through his radar observations and photography. Further, he gathers information through his radars that enable the pilot to penetrate the storm at its weakest point. A miscalculation in range, bearing, or altitude on the intense portions of the storm could easily place the aircraft in a hopeless situation, for the planes could not survive the stress of the intense weather cells in severe cloud build-ups.
The pilots and crews who fly hurricane reconnaissance flights are assigned to AEWRON Four in the same manner as personnel are assigned to any Navy billet. There are no specific requirements or qualifications other than proficiency in a basic flight specialty which must be met before a man can become a Hurricane Hunter. Once an individual is assigned to AEWRON Four, he receives intensive training in the methods and techniques used by the squadron to carry out hurricane reconnaissance.
Over the years, the Miami Joint Hurricane Central has also undergone changes until today it is the national nerve center for tropical storm research and forecasting. It, too, now has a new name, being presently designated as the Joint Hurricane Warning Center, composed of representatives of the Navy, Air Force, Federal Aviation Agency, and the Weather Bureau. It is the organization that releases storm warnings to the general public through the Weather Bureau. The Senior Navy Representative to the Joint Hurricane Warning Center is also the officer-in-charge of the Navy’s Fleet Hurricane Forecast Facility, the unit that is responsible for providing the naval establishment with adequate warnings on tropical storms.
To fulfill their responsibilities to the Joint Hurricane Warning Center, during the 1959 storm season, AEWRON Four regularly launched a reconnaissance flight every Monday, Wednesday, and Friday to survey the Gulf of Mexico. The flights averaged twelve hours in duration and completely covered the weather picture in that area. From the Hurricane Hunters’ advanced deployment unit at the Naval Station, Roosevelt Roads, Puerto Rico, other flights went far out over the Atlantic every Tuesday, Thursday, and Saturday. These flights into seldom-traveled regions that spawn over half of the hurricanes born each year, averaged about thirteen hours in length and covered a track distance of approximately 2,400 miles. In addition to these regular flights, special investigative flights were ready to go on one-hour notice from the Warning Center in Miami. AEWRON Four had seven Super Constellations and eight crews to carry out this full operational schedule.
Reports received in Miami from any reconnaissance flight are carefully plotted and compared with weather conditions in other parts of the areas investigated. From these comparisons and findings, storm predictions are made by the Joint Hurricane Warning Center. Conditions on which these predictions are based are wind shifts away from the normal easterly trade wind flow, falling atmospheric pressure, increases in sea states, and increases in wind velocities. Regions in which such changes occur are carefully watched, for these are the breeding signs of hurricanes. Any areas indicating an intensification of winds, sea states, rapid pressure drops, or abnormal precipitation are immediately put under constant surveillance by reconnaissance aircraft. To do this, a special flight is launched on orders from the Navy’s senior representative to the Joint Hurricane Warning Center, who also has operational control over AEWRON Four through ComEastSeaFron. If the flight finds a tropical storm or conditions favorable to a storm’s development, surveillance will continue until the storm develops and moves ashore, or until it dissipates.
Such investigative flights into suspicious areas are usually made at low-level, approximately 500 to 1,000 feet off the water, so that the Weather Officer can read surface winds and pressures. When all low-level data are collected, the plane climbs to 10,000 feet and later to 19,000 feet to obtain high-level readings. From the 10,000- and 19,000-foot levels, cloud formations can be observed on radar and in some cases visually. At designated points in the suspicious area dropsondes are ejected from the aircraft, which fall to the surface by parachute at the rate of about 1,000 feet-per-minute. Dropsondes are devices designed to be released in flight and relay to the plane by Morse code the atmospheric pressures, temperatures, and humidities from flight altitude to the surface.
All information obtained by the flight is relayed to the Joint Hurricane Warning Center half hourly. The Warning Center then determines if additional reconnaissance flights are necessary. Should a storm develop in an area under investigation, it is so designated and named by the U. S. Weather Bureau.
The efficiency and effectiveness of this federal service to the public can be readily shown. Prior to the establishment of the Joint Hurricane Warning Service, for every ten million dollars of property damage caused by tropical storms in the United States, about 400 people lost their lives. Today, that figure has been reduced to about four lives for the same amount of property damage.
The question usually arises in any discussion of hurricane reconnaissance flight techniques, why penetrate to the eye of the storm? Why not keep the aircraft safely on the outer fringes of the turbulent mass of tropical destruction and plot its position by radar? The answer is brief and simple. The primary information required by forecasters to predict the severity of storms is hidden in and about the eye. The position of the storm is, of course, important, but the real core of knowledge regarding the storm is behind the thick, black, wall clouds.
Within the storm, the trend in the intensity of the surface winds and the barometric pressures indicate to the weather observers the strength and potential development of the storm. At night, when it is impossible to observe surface winds visually, the barometric pressures obtained from the eye by dropsonde are used to predict tidal surges. During daylight hours, when it is possible to fly low and observe surface winds and surface pressures, it is possible for the forecaster to determine an even more accurate prediction of flooding and tidal surges. These predictions are of vital interest to low-lying coastal regions in the path of an approaching storm. For people in these areas must know more than just the fact that a storm is on the way; they need full information on its severity in order to take adequate precautionary measures.
It is interesting to note that surface wind observations in a storm are made by visual estimation by the weather officer. Checks on the accuracy of such observations, when available, have proven them to be extremely accurate. For the weather officer to “read” these surface winds, however, it is mandatory that the aircraft remain below the clouds—sometimes below 500 feet—so that the water will always be in sight.
Then, too, in most instances the wind eye, or in other words the focal point of the winds circulating about the storm center, is different from the radar or cloud eye. This leaves low-level penetration and investigation of pressure and winds as the best means bf determining the actual circulation center of a storm.
Without low-level penetration by the reconnaissance aircraft to the eye of the storm, the Joint Hurricane Warning Center would be unable to predict accurately the strength and track of a storm under their surveillance. Yet every individual engaged in hurricane research work feels and hopes that early warning is only a protective device for the present. Their final goal is to find some method of controlling or dissipating the storms themselves.
This year, for example, another step forward was taken in hurricane research. During the 1959 storm season, details and theories that had been worked out and proven over the past years resulted in a Navy reconnaissance aircraft of AEWRON Four being at the scene of an incipient storm. For the first time, radar photographs were taken of a hurricane—Gracie—from birth to death. Over a four-day period, more than 30,000 frames of film were taken, and the pictures gave meteorologists another tool to use in seeking an answer to the control of tropical storms. Until the final answer to the problem of storm control is found, however, early warning by reconnaissance aircraft remains the best solution to the immediate problem of protecting the public.
In September 1959, when Hurricane Gracie smashed ashore on the South Carolina coast, most of her fury was directed against Charleston. As previously stated, every detail of this storm was known to the Joint Hurricane Warning Center. The population in the path of the storm had complete and adequate warning on the approaching danger. When Gracie hit the coast, winds in excess of 130 miles-per-hour were reported by ground stations, yet only 22 deaths were reported as due to the storm.
Within the same week, however, Typhoon Vera struck the coast of Japan. Winds in this storm also were reported up to 135 miles-per-hour. Yet, when a count was made on the loss of life due to Vera, the figures showed that more than 5,000 persons were dead or missing.
Comparing the death toll of Vera with that of Gracie gives the American public substantial evidence of the value of Airborne Early Warning Squadron operations. It is one reason why the Navy’s Hurricane Hunters find their jobs very satisfying in addition to being difficult and exacting.
Lieutenant Commander Toole was commissioned in 1946 from the N.R.O.T.C. Unit at the University of North Carolina and served with the 7th Fleet. He entered flight training in 1950 and received his wings in 1951. He flew with Patrol Squadron Ten based in Brunswick, Maine until February 1954. He was then assigned to the Office of CNO as liaison officer with Headquarters, U. S. Air Force Intelligence. In 1957, he became Aide and Flag Lieutenant, Staff, ComMidEastFor. He reported to AEWRON Four in December 1958 and is presently assigned as Airframes Officer.