I. DEVELOPMENT OF THE INTEGRATED LANDING SYSTEM

This paper presents a description of a method now available for landing aircraft during adverse weather conditions which restrict visibility at airports. If investigations now under way are pursued to completion and are applied on a nationwide scale with the vigor their importance merits, there no longer will exist any reason for cancellation of commercial aviation operations, for the landing of airline passengers at fields hours away from their scheduled distinction by surface transportations, nor, most important of all, for the tragic loss of lives each year in crashes attributable to the inability of commercial and military aircraft to land at airports shrouded in fog, rain, or falling snow. To review the full story of the Integrated Landing System would require explaining in detail several exciting scientific investigations beginning long ago, which flowered under wartime pressure into the several components of that system. This is not the place to retell the complex story of radar; of radio beam instructions for air navigation; of the investigations into approach and runway lighting made by the army, navy, and Civil agencies concerned with aviation progress; nor of FIDO itself, although this first categorical answer to Mark Twain's famous epigram on talking about the weather has many interesting chapters.

The history of the Integrated Landing System is essentially that of the Landing Aids Experiment Station at Arcata, California, where the several partial answers to aviation's bad weather problem were first combined into a method of operations which permits landings to continue on a routine basis even when the runway is invisible from the control tower. The Landing Aids Experiment Station is an outgrowth of a meeting held in Washington, D. C., on September 20, 1943. At that time the Navy Department was planning an air station in the Aleutian Islands. Among the many problems requiring solutions before the Aleutian base could be made effective for operations against the Japanese was that of overcoming the heavy advection fogs which blanket the Aleutian area much of the time. A two-year study of the region indicated that heavy fog might be expected 50 per cent of the time between May and September, and 10 per cent of the time during the remainder of the year. Aleutian fogs are often 4,000 feet thick and are accompanied by winds as high as 35 miles per hour. Obviously, such conditions would seriously hamper the use of air power in the Aleutian theatre.

On September 20 and 23, 1943, meetings were held in the Navy Office of the Coordinator of Research and Development for the purpose of discussing means of handling the Aleutian problem. Scientists of the National Defense Research Council met with interested naval officers, including Commander J. P. Lurger, USN, who represented the Navy Bureau of Aeronautics, and former commander R.L. Champion, who represented the bureau of yards and docks. At this meeting plans were laid for thoroughly investigating British developments in fog dispersal using gasoline burners and also for studying other methods including sonic coagulation. During November and December of 1943, the two Navy representatives examined FIDO installations in Britain and discussed the technical problems involved, with British authorities; the Haigill vaporizing burner was selected as the most suitable for Aleutian conditions. In January and February, 1944, tests were conducted at Sandburg, California on Sonic methods for dispersing fog. Although a 50 percent increase in the visibility was obtained (from 200 to 400 feet) the method did not appear practical for Aleutian fogs. So, in March, 1944, because of the need for haste, a FIDO installation was scheduled for the Amchitka Army Air Forces, who were also interested in the possibilities of FIDO equipment.

A full scale Haigill-type burner installation was fabricated at Amchitka. Navy Construction Battalions moved enormous quantities of tundra to provide burner foundations, drilled and assembled miles of burner and pre-heater pipe, laid supply lines to a new fuel storage area and pumping station. Working at top speed, they completed and tested the gigantic furnace in July, 1944, subsequently turning it over to the Army Air Forces for operational use. After the completion and successful testing of the Amchitka FIDO installation, Commander Champion returned to the United States convinced that an experimental station should be established within the continental limits at some locality having a high incidence of fog, so that all types of equipment for facilitating the operation of aircraft in adverse weather might be thoroughly tested and speedily approved for general use. Gaining official Navy support, he visited again in Britain to keep abreast of new developments during the Normandy operation, when portable FIDO burners were being carried along by advancing front line air support arms. Following this visit, he was authorized to select a suitable location for an Experimental Station. In the course of his survey he visited air stations along the entire Pacific Coast.

Meteorological conditions along the West Coast favor a high incidence of fog. The Aleutian current, which flows eastward across the North Pacific, continues down the west coast of North America produces a belt of cold water along the coastline. This secondary stream, known as the California Current, upwells at two points along the coast. The Landing Aids Experimental Station is located almost at the center of the most northerly point of upwelling. The Eastern Pacific cell of high pressure creates a westerly flow of air to the coast, especially during the summer months, when the cell migrates northward. Just before reaching the coast, these moist and relatively warm tropical air masses pass over the colder California Current. Their lower strata are cooled by the contact, with the result that heavy advection fogs are of common occurrence along the coast. The Landing Aids Experiment Station, therefore, is ideally located for tests of landing aids equipment. In addition, heavy winter rainfalls provide ample opportunity for investigating navigational aids in all types of weather.

According, the Navy Bureau of Aeronautics requested the construction at Arcata of the most effective FIDO systems then known, and the installation of the ISL (SCS-51) low approach systems for directing aircraft to the runway in low visibility. Construction of these facilities at Arcata was begun in March, 1945, by Navy C.B. personnel. These installations include the following FIDO types:

Slot

Hades-Rapex

PWD Non-Glare

Haifox Portable

All the above types burn vaporized gasoline, varying principally in the methods used for pre-heating the fuel, and in their thermal output. The Slot, Haigill, Haifox, and PWD Non Glare burners all operate on a principle similar to that used in a gasoline stove. The vaporizer is a supply tube suspended parallel with and above the burner tube to which it is connected at the end of the burner unit. The Hades-Rapex burner has a separate vaporizer unit in which sufficient fuel is vaporized to supply approximately 1500 feet of burner line.

The thermal output of the vaporizing burners is variable from approximately 15 to 50 therms per yard hour, except for the Hades-Rapex which can be designed to produce a maximum of 80 therms per yard hour.

In addition, an entirely new type of FIDO was projected for installation at Arcata. This is the High Pressure Atomizing Burner, the design for which was developed by the Babcock and Wicox Company of Barberton, Ohio, under contract with the Bureau of Yards and Docks. Featuring instantaneous ignition, ability to burn on low-priced diesel oil, fully automatic operation, and simplified construction, it promised to reduce the cost of FIDO to a figure which would make its use economically feasible in peace time commercial aviation.

The low pressure FIDO burners along the instrument runway, comprising approximately 12,000 feet of burner lines, were largely completed during the Summer and Fall of 1945. This work was accomplished by U.S. Navy Construction Battalions. It included, in addition to the burners, a low pressure pumping station for supplying the burners, a tankfarm having storage capacity for 200,000 gallons of gasoline and 40,000 gallons of diesel fuel, a railroad siding for tank car delivery, and a 4,500 foot six-inch pipe line from the railroad to the tank farm. In addition, Navy Electronics personnel installed the ILS [SCS-51] radio beam low approach system along the LAES instrument runway. Test of the slots and Hades burners, and flight tests of the FIDO installations in combination with the ILS were conducted in September, October, and November of 1945. The University of California participated in these preliminary tests.

During the winter of 1945-46, discharge of naval personnel made it necessary to adopt other methods for completing construction at Arcata. The bureau of yards and docks let a contract for completion of the additional low pressure burners enclosing the cross runway, and the new high pressure system. This work included the installation of a Byron-Jackson 9-stage centrifugal pump, powered by a GE 800 horsepower motor, which can supply 840 gallons of fuel per minute to the high pressure burners at a pressure of 1800 pounds per square inch. Since the local electric company was unable to supply the power required for operation of the high pressure system [750 kilowatts], three diesel-powered electric generators were also installed to operate the high pressure pump. This part of the work was completed by 30 April, except for final tests and adjustments.

With the end of the war in 1945 the termination of security restrictions released a flood of interest in wartime blind landing equipment. During the war, airlines had flown greatly expanded schedules without these aids, but, becoming cognizant of the Navy's Fog Dispersal and GCA achievements, and of the Instrument Landing System and new approach and runway lighting developments which were nearing perfection at the AAF equipment laboratory they were intensely interested in seeing what immediate applications might be possible in commercial aviation the civil aeronautics authority by congress with responsibility for assuring safe operation of the air ways was likewise concerned the sponsors of the Arcata Experiment Station therefore considered it highly desirable to broaden its scope to cover the development and testing of all types of landing aids. Also in order to fully coordinate the efforts of the several agencies, reduce development cost avoid duplications and assure the speedy standardization of the best equipments it seemed highly desirable that the landing aids experiment station be made a joint activity of the Army, Navy, CAA and the air lines.

Accordingly Commander Champion was assigned the task of organizing these varied interest into a concrete joint program enthusiastic support was immediately forthcoming from Lt. Colonel W.T. Harding of the Air Material Command, Wright Field. Harding was already concerned with the selection of locality for the testing of new ideas in approach and runaway lighting and at once proceeded to set up a project and provide funds for its testing at Arcata. Similarly, Lt. Col. Joe Bishop of the Equipment Laboratory at Wright field has also agreed to cooperate. His concern for the testing of FIDO installations which could not be accomplished at Wright Field because of the almost complete absence of fog. Mr. Frank Richardson of the AAF also support the army interest in the project. CAB participation was implemented by Joe Duckworth and Charles Cary, who assisted in organizing the combined activity. Interest of the CAA in the work was formulated by W. A.. Burden, Ted Wright, Jim Angier, Les Vipond, and Cory Pearson. Milt Arnold represented the Air Transport Association. With this impressive backing, and with the support of Rear Admirals Richardson and Combs and Mr. Frederick Sass of the Bureau of Aeronautics, Commander Lunger and Commander Champion obtained approval from the Chief of Naval Operations for the deactivation of the Naval Auxiliary Air Station, and its conversion into an Army-Navy-Civil Landing Aids Experiment Station. The Navy Bureau of Aeronautics was designated as the coordinating agency to be charged with the operation of the station through a suitable research contract.

NAAS, Arcata, was deactivated on April 30, 1946, and management of the Landing Aids Experiment Station was transferred to the University of Southern California on a letter of intent issued by the Bureau of Aeronautics. During the month of May, 1946, the station remained in caretaker status. Difficulties in negotiating the BuAer contract and a change of University policy forced USC to withdraw from the contract on June 4, 1946.

In the meantime, United Air Lines had become interested in the work projected at the Landing Aids Experiment Station. Only a commercial airline, perhaps, could fully appreciate the necessity for, and the promise of, a unified and fully organized attack on the low visibility problem now, making use of all the available devices and skills developed during the war for overcoming its hindrance to all weather operation. A contract, therefore, was let to United Air Lines for continuing the experiments at Arcata.

The compelling reason for United's interest in the landing aids experiment station may best be shown by considering the losses sustained by this one airline as result of interrupted flights and canceled schedules during 1946. The direct out-of-pocket costs for housing and feeding passengers at alternate terminals, arranging surface transportation during sustained periods of adverse weather, and other related expenses, amounted to $150,000. An additional revenue of approximately $2,300,000 was also lost. It is estimated that passengers scheduled to be carried on flights which were cancelled at the point of organizing 1946 would have paid this amount in fares. To this $2,450,000 loss, which can be directly estimated from the airline's traffic figures, must be added an indeterminable sum representing the revenue which would be paid by persons who are at present discouraged from air travel because they may not be able to suit surface transportation, especially during the winter months, when adverse weather is most likely to disrupt airline traffic. Revenue lost because of this factor cannot be accurately measured, but probably runs into the millions. It should be remembered that these figures represent the losses only one of several major airlines. And it should also be pointed out that they may well mean the difference between prosperity and bankruptcy for any one airline. It can be seen, therefore, why United Air Lines and the Air Transport Association were anxious to see the work at LAES proceed with all possible speed.

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