The opinion of the court was delivered by: DOOLING
Nine major American-flag air carriers, the Port of New York Authority, Charles H. Ruby as president of the Air Line Pilots Association, three air line pilots, individually and as representatives of their class, and the Administrator of the Federal Aviation Agency (as intervenor) have sued to enjoin the enforcement against them of the Town of Hempstead Unnecessary Noise Ordinance (No. 25), Article II, as amended March 10, 1964, so far as it applies to aircraft using John F. Kennedy International Airport. Plaintiffs have moved for a preliminary injunction against the enforcement of the ordinance and defendants have moved for a preliminary injunction against violations of the ordinance by the plaintiffs. Some four thousand pages of testimony have been taken, elaborate affidavits and detailed exhibits have been presented and the parties have, in addition, agreed in effect on many of the background and underlying facts. In addition, tape recordings of actual flyovers monitored by the Town's acoustical expert were played back under controlled conditions which reproduced in the Courtroom as nearly as possible the actual experience of flyovers against a background of normal domestic sounds.
It is concluded that the plaintiffs and intervenor are entitled to enjoin pendente lite enforcement of the Ordinance and that the Town is not entitled to a preliminary injunction against violations of the Ordinance by the plaintiffs. The facts have been found separately and will not be repeated in detail here.
The Town of Hempstead lies east of Kennedy Airport and extends both farther north and farther south than the Airport. Some 150,000 residents of Hempstead live within four miles of the Airport. The easterly ends of the five runway strips at Kennedy Airport are from 1,300 to 20,850 feet from the Hempstead boundary.
The conflict in the present case arises out of the Town's addition to its Unnecessary Noise Ordinance of a new article forbidding anyone from operating a mechanism or device (including airplanes) which creates a noise within the Town exceeding either of two "limiting noise spectra." The noise spectra are set out in two tables; the Table I spectrum sets out eight octave bands of center frequencies (in cycles per second) from 63 in the first octave band to 8,000 in the eighth octave band, and sets forth the noise limit for each band in decibels of "band pressure level" (referred to the conventional base of 0.0002 microbars, considered the pressure level of a sound at the threshold of audibility). The decibel limits range from 92 decibels in the first or lowest pitched band to 52 decibels in the eighth or highest pitched band, thus recognizing that high pitched sounds are more "annoying" than low pitched sounds of equal pressure level. The Ordinance treats as a violation any transient noise having a "duration" exceeding twelve seconds in the daytime hours 7:00 A.M. to 7:00 P.M., or exceeding six seconds in the night hours 7:00 P.M. to 7:00 A.M. The second or Table II spectrum applies to "steady noise" exceeding one minute in duration and the limiting band pressure levels are, in each octave band, 20 decibels lower than the corresponding Table I value. "Duration" of transient noise (during the entire period when the noise from a source is first distinguished from the ambient noise until the noise from that same source finally recedes into the ambient noise) is defined as the time beginning when the noise first exceeds a certain band pressure level until it no longer exceeds the same band pressure level, provided it remains above the same band pressure level for at least one-third of the total "duration." Exceeding the band pressure level in any one octave band is a violation even if all other octave band noises are well below their limiting levels. It is not suggested that the "limiting noise spectra" of the Ordinance are unreasonably low viewed as stating sound levels above which noise is irritatingly loud when heard in private dwellings.
There is no question, indeed both sides insist, that take-offs from and landing approaches to Kennedy Airport regularly produce noise that exceeds the limiting noise spectrum of Table I in Hempstead while the aircraft are passing over parts of the Town. And, in what may be taken to be a typical enough year, in 48% of the landings the aircraft passed over some part of Hempstead and in 36% of the take-offs the aircraft passed over some part of Hempstead. The parties assume that Kennedy Airport will be used more intensively in future, and that in general, the aircraft using the Airport will be larger and will use jet engines of greater thrust than those presently in use.
Plaintiffs and the intervenor contend that the Town is impotent to impose such anti-noise legislation as is here involved because it amounts to forbidden regulation of interstate and foreign commerce. Defendants contend that the Ordinance is a proper exercise of police power to protect the welfare of its citizens and that it does not operate in any field actually occupied by federal action or peculiarly reserved for federal action. Defendants argue strenuously that overflights can be all but eliminated by changing take-off and landing approach procedures in logical extension of existing procedures already approved by the Federal Aviation Agency (FAA) for certain take-offs and landings at Kennedy Airport.
It would be difficult to exaggerate the magnitude of the regional and national commitment to Kennedy Airport, and the importance of its role in the interstate and intercontinental transport of mail, passengers and cargo, and it is needless to add that air transport, and particularly long distance air transport, is not an optional alternative to ground and water transport but is indispensable. The two other major airports serving the greater Metropolitan area, LaGuardia and Newark, operated under a common control through the Port of New York Authority, do not, with Kennedy, provide all the airport capacity the region requires. The search for new airport facilities to relieve the overburdened airports of the present and make room for the future has been publicly conducted for years.
In the years since 1948, when the Port Authority undertook to operate Kennedy, turbo and fan jet aircraft have all but displaced turbo and piston driven propeller craft. Larger, heavier and faster than propeller craft, the jets have demanded lengthened runways, and exacted new constants of air traffic management. Broadly, the airport base they required, was, in absolute terms, larger in every dimension than what had been required for propeller craft, and the inverted truncated cone of air space resting on the airport, that can be thought of as representing the zone marked by the jets landing glide slopes of about three degrees, was far nearer the edges of the airport and closer down on the bordering communities. It was as if every existing propeller craft runway had been suddenly moved out toward the boundary of the airport. The margin of laterally insulating air that had sheltered the neighborhood of the airport from take-off and landing noise was radically reduced and the impact on the surrounding communities was marked and unhappy.
The Town of Hempstead, neighboring the Airport to its east, is the largest town in the State. It is 128 square miles in area and has grown rapidly in population in recent years; its population was 432,506 in 1950, was 740,738 in 1960, and was estimated at nearly 806,000 in September 1963. In 1964 there were about 225,000 dwelling units in the town, and the population density in the areas nearest to the Airport exceeded 10,000 persons per square mile. It is estimated that 150,000 people live in the incorporated villages that lie within three miles of the Airport. The Town is primarily residential.
The problem with which the Town Ordinance deals does not affect the whole Town. Parts of the Town - Levittown and Wantagh, for example - are as far from the center of the Airport as is Central Park. Thickly populated areas in Queens, including the Rockaway Peninsula, and Brooklyn are as close to the center of the Airport as the northwest corner of the Town, which is affected by flights taking off from or landing on the northeast - southwest oriented runways at Kennedy. The noise problem is not peculiar to Hempstead nor does it equally affect the many communities in the Town. It is a problem that affects communities in terms of their proximity to the Airport quite without reference to town, city and borough boundaries.
The dimensions of the noise problem cannot be minimized. It is, however, one of the manifold of environmental problems that press on a society in which the pace of industrialization steadily outstrips the capacity to deal with its modification of the total environment of urban and suburban existence. Perhaps the aircraft noise problem differs in that it appears to be unavoidable, in the present stage of technical development, and not a consequence of the failure to take feasible precautions or to provide practical remedies.
The testimony has dealt mostly with turbo-jet and turbo-fan aircraft since they are the ones on which the problem centers and they are steadily displacing propeller driven aircraft. The testimony - and this area is non-controversial - showed that the noise sources are the compressor whine produced by beating of the blades and vanes on the air and the sound produced outside the engine by the exhaust discharge, moving at high velocity and shearing through the ambient air and dragging it along in eddies that increase in size as they are swept along. The sound wave length - and sound pitch - of the eddies is related to their diameter. Turbo-jet and turbo-fan engines, while broadly similar as noise sources, differ in that the wake velocity of the turbo-fan is relatively lower and more of the energy of the engine is used in the compressor, which has an annular discharge directly to the air. Jet aircraft noise is thus predominantly the product of relative mass flow between the ambient air and exhaust discharge. There is no indication that it could be muffled like an automobile engine or that progress in diminishing noise-production by jet engines can in the foreseeable future do more than mitigate it by such advances as the turbo-fan represents in relation to the turbo-jet.
Given the jet engine, with its noise characteristics, the amount of noise it produces in service as it affects the neighborhood of an Airport is determined by the airframe of the aircraft, its take-off weight or landing weight, the thrust applied by its engines, the flap setting of the wings and other physical constants. The evidence showed plainly take-offs and landings are essentially mathematical solutions of problems in physics and not inspirational piloting. The evidence is very clear that a very high degree of skill and judgment in the piloting of aircraft is indispensable, but the point is that, to the uninitiate, the flght manual is an immense array of graphs and tables that translate aircraft weight, air temperature and humidity, change in weight during flight due to fuel loss, radius of ...