The Air Can Be Safer
by T. P. WRIGHT
FOUR fatal accidents occurred to U.S. air carriers during the last seven days of 1946. The sensational headlines which followed were a shock to many readers; yet despite these accidents the fact remains that the safety record of U.S. airlines for the entire year 1946 was the best in history. Although flying more than 7 billion passenger miles, almost double the 1945 amount of civilian flying, they had only 11 fatal accidents, against 10 in 1945. This means that the passenger fatality rate per 100 million passenger miles, which is the best, measure of risk, was cut from 2.31 for 1945 to 1.60 for 1946.
Airline travel is still not so safe as rail or bus travel, but it is much safer than riding in passenger automobiles. Of the 100,000 persons killed by accidents of all kinds in the United States last year, 30,000 were killed by automobiles, against 73 in accidents of the scheduled airlines.
Plane travel can be made still safer in 1947 and the years to follow if the American people are prepared to invest the funds needed to install and operate the improved air navigation aids already available, and to perfect new safety aids now in an experimental stage.
The Civil Aeronautics Administration is by no means complacent about the safety problem, and is constantly analyzing accident causes and seeking remedies. What were the major causes of airline accidents in 1946, and what can be done to eliminate them?
Causes of accidents
Most numerous on the list of last year’s fatal accidents were those which occurred during the approach or landing, in many cases with a low ceiling.
We are attacking this situation in two ways. First, there is the installation, now well under way, of radio, radar, and lighting aids, which ultimately will make landings under any weather conditions as reliable as those carried out today under “contact” — that is, with clear view of the ground. Next we are changing two rules governing airline operations. One change requires pilots to abide by any Weather Bureau report on ceilings at airports, whether estimated or scientifically measured; this wall curb any tendency to make landings in hazardous, borderline weather. The other increases the minimum ceilings for four-engine planes, which need more maneuvering space than smaller twin-engine types.
To keep airplanes from running into the sides of mountains, our remedy is better aids to navigation, and we are confident that CAA can provide these if sufficient funds are made available. Again, an intensive study has been made of fire in the air, resulting in a new set of specifications for preventing, detecting, checking, and extinguishing fires.
Some people will ask, “What about the human element? Are unfit pilots and mechanics responsible for these accidents?” I think not. Our airline captains are men with thousands of hours of flying experience, who regularly take the most stringent physical examinations and flight tests to determine continued proficiency. Furthermore, they are limited by regulation to a maximum of 100 hours of flying a month, to prevent fatigue. Nevertheless, we are studying the vast accumulation of war data on aviation psychology to determine whether methods of selecting and training pilots can be improved.
While it is necessary to put many accidents down on the books as caused by pilot error, I am inclined to think that in a good number of these the error would not have occurred if the pilot had had better navigation aids. As for the mechanics, there is almost no evidence of improper maintenance causing accidents.
The big question mark, then, is navigation aids.
What have we learned in peace or in war of devices that will make flying safer? How many of these devices are immediately applicable to civil use? And what will it cost to install them?
Wartime developments
The public has obtained an unfounded Impression that wartime developments offer a ready-to-hand solution of all our problems in this field. Top leaders of the armed forces make no such claims. As Lieutenant General Ira C. Eaker told the House Interstate Commerce Committee, “The military must accept safety factors which are much lower than the civil operators can afford to accept. For example, in wartime we cleared airports with heavily loaded planes carrying tons of high explosives under weather conditions and under operational systems which would be unthinkable for peacetime operations and which certainly could not be adapted to civil aviation; the hazards would be too great.”
Statistics submitted by the armed services to the same committee underline this point. They show that the passenger fatality rate of the Army Air Transport Command was four times as high as that of the commercial airlines in 1944, about twice as high in 1945, and almost five times as high in 1946. The Naval Air Transport Service safety record was somewhat better than that of its sister service, but still not comparable with that of the civil airlines.
Much exploratory work remains to be done, work of a kind that is both costly and time-consuming. It costs a great deal of money — and I mean hundreds of millions of dollars — to develop, install, maintain, and operate airways devices that make for all-weather flying, and to build or improve airports that will make for speedier service to air travelers.
Who is to pay?
If the money for airways aids is to come from the Federal government — as it appears it will have to — Congress must be convinced beyond doubt that the national interest warrants such expenditures. Under our Federal budgetary system, estimates must be prepared a year and a half before the money actually will be spent, a difficult requirement to meet in industries that advance as rapidly as aviation and electronics.
If local government is to provide a part of the funds — as it is being called on to do in the case of airports — the voters must usually be persuaded that it is good business to float a bond issue.
And if the airlines themselves are to make an investment, particularly in their present difficult financial situation, they must have some assurance that It will be recouped by earnings within a reasonable period.
In drawing up a realistic program for civil aviation, CAA has given due regard to these economic factors. We believe the nation can follow this program with confidence over the next five to ten years.
Immediate safety aids
The heart of the airways problem is to provide facilities which will make flying safe where it now may be dangerous, regular where it is now uncertain.
Heading the list of these facilities in the CAA program is a comprehensive instrument landing system. With such a system, we expect to cut in half the time spent waiting in aerial “stacks,” by speeding up the frequency of landings from one every five minutes or more to one every three minutes or less; to eliminate the “missed approaches,” which at best delay other planes waiting to land and at worst cause fatal accidents; and to make possible a progressive lowering of minimum ceilings for improved regularity of airline operations.
In layman’s language, lowering of minimum ceilings for airline operations means there will be fewer occasions when the traveler is told, “Sorry, your flight is canceled because the airport at your destination is ‘closed in.’”
Our objective is to reduce from 500 to 200 feet the minimum cloud ceiling under which airline landings are permitted, and to reduce the visibility requirements correspondingly, both with no sacrifice of safety. This will reduce the proportion of unflyable weather at most airports from 6 or 7 per cent at present to 1 or 2 per cent. Boston Airport, for example, last year was closed by bad weather a total of 379 hours, equivalent to almost 16 full days. It should be possible in about a year to slash the unflyable time at Boston by two thirds, permitting safe and speedier landings, on instruments or otherwise, for the equivalent of 360 full days.
The comprehensive instrument landing system that CAA is installing to achieve these objectives has three major components: radio, lights, and radar. The radio element essentially consists of two “beams” —one known as the localizer, extending in a vertical plane down the center line of the runway and for a considerable distance beyond; the other, known as the glide path, at an angle of 2½ degrees to the ground, which intersects the localizer and gives the pilot the correct air roadway for descent. These signals actuate a cross-pointer instrument dial from which the pilot gets a constant picture of his relation to the on-course path. He simply adjusts his course to the right or left, up or down, as may be required in order to keep the two needles centered. A third radio feature is some form of distance indication — at the present time, marker beacons which, when flown over, cause lights to flash on the instrument panel at known distances from the “touch down” point. Our plans call for these to be replaced later on by distance measuring equipment (DME) which gives a constant reading, on a dial, of distance from the airport.
Approach light lanes, now of the neon bar type, later to be superseded by high-intensity units, are a very important feature of the instrument landing system. Even in the worst weather, they enable the pilot to see the ground during the last 50 to 100 feet of descent, after he has broken out of the overcast.
Installation of localizers, glide paths, markers, and approach lights was begun by CAA before the war, but with our entry into the war the Army took over all the facilities existing or on order. They made good use of the instrument landing system, which is credited with hundreds of “saves” at airports in the Pacific. Now the system is installed at 33 or more civil airports, with another 133 airports scheduled for installations during the next two years if funds are made available. The airlines encountered delays in obtaining the receiving equipment necessary to take advantage of the localizer and glide path signals, but now have the proper sets in about half of their domestic fleet of 683 planes, and are proceeding rapidly with the training of their 5000 pilots in the use of the system. By the time bad weather rolls around again, landings by this means will have become routine, and I am confident U.S. aviation will never experience another “black week” like Christmas week, 1946.
Radar
The place of radar in our program has been the subject of vigorous debate. CAA has been pictured as resisting and delaying the civilian use of radar. To end that false impression, I want to state flatly that we consider ground radar an integral part of our instrument landing program. Air-borne radar for collision avoidance still must be made more accurate and lighter for general civil use, but CAA now has had sufficient time to develop ground radar to the point where we are pressing for its installation in a large number of CAA-operated airport traffic control towers.
In all cases, the tower radar will be used for traffic surveillance, enabling the controller to see on a scanning screen, even in bad weather, the movement of planes within a radius of 20 miles. It will thus be possible to eliminate many of the questions and answers as to position which now must be conducted between plane and tower by two-way radio, speeding up landing and take-off clearances to that extent and assuring the safe operation of all aircraft.
At congested airports, we plan to install the more precise radar screens associated with the ground controlled approach or “talk down” system (GCA). Already operating in the New York, Chicago, and Washington towers, these are scheduled for twentysix others if the funds are made available. The GCA type of radar will serve both as a double check on the radio facilities, permitting the tower to advise the pilot if he is not following the localizer and glide path properly, and as a primary means of guiding to a safe landing any pilot in distress who does not have the localizer and glide path receivers, or any pilot who wants to descend under GCA ground directions.
Loan of equipment by the Army Air Forces, financing of installation work by the Air Transport Association, training of personnel by the manufacturer of the radar equipment, and actual operation and maintenance of the facilities by CAA make possible the current use of GCA at three stations. The joint endeavor reflects the effort that has been and is being made by all groups interested in civil aviation to utilize radar at the earliest possible moment consistent with safety. It is important to note, however, that the three radar sets in use are only on loan, and that the CAA personnel monitoring them have been diverted from other operations at a time when we have been forced to discontinue service at fifty-five communications stations because of lack of funds. The continuation and expansion of this radar program hinges entirely on Congressional appropriations.
Aids en route
Just as this radio-lights-radar combination will increase safety and speed of operations at airports, other devices are now available for swifter and surer navigation between airports. Completion of the CAA’s three-year program for installation of such devices should put an end to those accidents in which aircraft smash into mountainsides.
A new type of radio range is the heart of this program. The radio range now in general use on our 40,000 miles of airways transmits, on low frequencies, directional signals along four courses.
Use of this device during the last two decades has been an important factor in making U.S. airlines from three to twenty times as safe as those of other countries. Its defects, however, have been known to us for some time, and only the severe restrictions of war kept us from undertaking earlier a scheduled replacement program.
Static and interference on the low frequencies often make it difficult to fly “on the beam,” and if for this or any other reason the pilot gets off the 10-mile-wide range course, he is in danger of getting lost, particularly in bad weather.
The new type of range, however, assures clear reception under all atmospheric conditions by transmitting on very high frequencies, and furnishes courses in all directions instead of just four. With enough VHF omni-directional ranges, it would be virtually impossible for a pilot to get lost, for the whole air space over the United States becomes a radio-tracked airway.
Not only will the pilot be sure, through the VHF range, what course he is flying, but he will know at all times exactly how far he is from the range, by means of distance measuring equipment now in an advanced stage of development.
A small radio transmitter in the plane sends out a signal which “trips” a transmitter at the ground station, and the ground transmitter’s signal is then received back in the plane. (This differs from radar, which involves “bouncing” a single signal.) The time taken by the signals to travel is translated into mileage and registered on a simple dial in the cockpit. To obtain his distance from the ground station, the pilot needs only to glance at this dial, instead of interpreting with the aid of a map the signals of radio marker beacons (which, incidentally, are more expensive to install and maintain).
The combination of VHF omni-directional ranges and DME, in addition to increasing safety, will make it possible to move a greater volume of traffic without delays, by permitting planes to fly along several parallel channels of an airway.
The VHF range will be a boon on shorter hops, such as New York to Boston. VHF signals do not carry far enough for long-distance navigation, however. We have therefore started to install a grid of omni-directional ranges transmitting on low frequencies, but with high power. Airplanes making long-distance, nonstop flights — from coast to coast, for example — will use these ranges to navigate speedily on high altitude, great-circle courses, avoiding the “dog legs” and heavy traffic of existing airways and taking advantage of good weather and favorable winds.
Airports
Advances in electronic and lighting aids cannot alter the fact that the ultimate speed and safety of air traffic are limited by the capacity of the airport itself. The number and arrangement of runways and taxiways definitely fix the number of planes that can be dispatched and landed safely, and in this respect many of our older airports are serious bottlenecks. Aggravating the situation in some cases are airport locations unduly subject to ground fog or blankets of industrial smoke.
We must modernize our airports as well as our airways, and to this end Congress has authorized a seven-year Federal aid program, under which the first construction is about to start. This year we have sufficient funds to help local agencies start construction of 388 new airports and improvement of 412 existing fields. During the entire seven years, we hope the program will result in about 2700 new airports and improvement of about 2000 others.
Roughly 40 per cent of the Federal money will be used to build or improve some 450 large airports of the type used by the airlines. Many of the 4000-odd smaller airports in the program, however, either will be used jointly by the air carriers and personal flyers, or will serve to free airline terminals of other traffic for efficient handling of scheduled operations. It is obviously difficult to arrange with safety a series of landings involving, on the one hand, scheduled liners that approach the airport at 125 miles an hour or more and are fully equipped with radio, and on the other hand, private planes that come in at 60 miles an hour or less, and can be directed only by flag or light gun signals. Non-scheduled flying is increasing at an unprecedented rate, but until a city can offer local or itinerant private flyers adequate fields other than the terminal airport, it is hardly in a position to wave them away from what is, after all, a public facility.
In approving proposals for construction of large airports with Federal aid, CAA will guard the interests of air travelers who now suffer from poor planning of many older airports. Today it may be necessary to spend a full hour crawling through heavy traffic between the downtown area and the airport. All other factors being equal, CAA will require a location that can be reached quickly. Field and buildings will have to be designed for expeditious movement of passengers, cargo, and aircraft — not only today, but in the years of expanding air traffic that lie ahead. Ultimately, we envision some airports handling as high as 300 movements per hour by means of 12 specially arranged runways and a system of landing aids.
For the future
Automatic all-weather flying is the keynote for future development. Likely to be introduced at an early date are automatic instrument landings. By having the signals from the instrument landing localizer and glide path transmitters actuate the automatic pilot, the plane can be brought in with great accuracy. The human pilot actually can keep his hands off the controls, acting only as a monitor until he takes over the very last stage of setting the plane on the ground.
Despite the perfect safety record of our traffic control activity — no collisions between scheduled airliners in ten years of operation — the increasing volume and speed of airway flights make it desirable also to introduce automatic elements into the traffic control system. Already the posting of flight movements on boards at busy CAA traffic control centers like New York approaches confusion, just as would be the case in a stock exchange if the personnel tried by hand to chalk up market changes on a blackboard. We hope to see automatic electric posting boards installed in our twenty-six air traffic control centers, followed by something similar to the railroad block signals to obviate the need for radio telephone or telegraph messages concerning the pilot’s position and progress en route.
Finally, we are investigating a number of systems which, by radio, radar, television, or a combination of these methods, propose to consolidate for the pilot in simplified form the complete information needed to navigate from take-off to landing. These include such sounding devices as Lanac, Navar, and Teleran, all of which offer interesting possibilities for the future.
These long-range development plans for the airways will be carried on just as intensively as funds permit, but in the interests of public safety we will skip no stage in the time-tested sequence for achieving technical advancement: research, to get fundamentals; development, to work out practical devices; service test, to prove their merit to the user; and then production, to consolidate gains in a system for general application. If it is taking years for an entertainment device like television to reach widespread usage, at least equal patience must be exercised in the introduction of devices to which we entrust human lives.
Coöperative effort
In the task of making air travel safer and faster, there is close collaboration between CAA and the aviation industry, both the manufacturers of navigation equipment and the airway users. From the industry, the air traveler can and should expect a number of improvements. For example, better service at airports, in ticketing, baggage handling, and all other such phases, appears to be at hand as the result of an experiment being conducted by the airlines at Willow Run Airport, Detroit. There, a joint corporation sponsored by all airlines using the airport has been set up to provide the various terminal services now handled by them separately.
Basically, the air public demands just three things: safety, maximum speed and regularity, and fares that represent a reasonable price.
The present average fare of 4.5 cents per passenger mile is the lowest in history, and although it is not the ultimate goal, it represents real value in the face of rising prices generally.
To a considerable degree, the public itself will write the ticket on safety and the elimination of delays. The taxpayers will have to determine how far they want to go in underwriting the modernization of our airways, which were forced to remain virtually static during the four years of war. Eventually, I believe, the airlines will be able to participate substantially in the cost of maintaining and operating air navigation aids. That time has not yet arrived; and in any case, the initial investment for establishing the facilities should properly be made by the Federal government.
The public, through its representatives in Congress, has endorsed the expenditure of half a billion dollars of Federal money on airport construction in the next seven years. A decision of comparable magnitude must be made as to public policy on airways aids, which are so closely integrated with airports in actual living practice.
If given the go-ahead, CAA is ready to undertake a carefully planned program of airways modernization. The technical details involved in that program represent not only the best U.S. thinking, but were endorsed almost 100 per cent for world-wide application by the foremost technicians of twenty-six nations, who met in Montreal after a series of radio aids demonstrations in England, the United States, and Canada.
Given the necessary public support, the government will carry forward this program with the same technical thoroughness which has brought the United States its present leadership in world aviation. Simultaneously, the industry can be expected to subject itself to intensive self-criticism and improvement, resulting in more efficient and selfsustaining operations. Out of this combined effort, the public will get transportation by air which will offer a combination of speed, regularity, and safety beyond anything the world has seen.