Public Demands and Technological Response: Austin Tobin, Leo Beranek and the Advent of Jet ...

19 Pages·2017·0.55 MB·English

by  John Ackroyd

Journal of Aeronautical History Paper No. 2017/03
Public Demands and Technological Response: Austin
Tobin, Leo Beranek and the Advent of Jet Travel

Jameson W. Doig
Research Professor in Government, Dartmouth College;
Professor Emeritus, Princeton University

Abstract

As the Luddite protests in the 19th Century and resistance in the 20th Century to building
nuclear power plants illustrate, technological change often generates powerful public
opposition. In some instances, however, scientific strategies, joined with sustained pressure
from well-placed supporters, can be used to ameliorate the worst effects of technological
change - as the case described below illustrates.

When Pan Am tried to introduce jet planes for travel in the US and across the Atlantic, it
generated a battle that lasted more than two years. The public agency that operated all three
major airports in the New York region - the Port Authority - had been designed to encourage
its officials to emphasize scientifically based analysis in setting policy; and the agency's
leader, Austin Tobin, had developed a strong reputation for political independence and
integrity. He also had previous encounters with the airlines, described below, leading him to
be suspicious of their assertion that jet planes were not unduly noisy. Therefore, to test jet
noise, he recruited the nation's premier acoustical engineer, Leo Beranek, and when Beranek
concluded that jets were perceived to be much louder than expected, the aircraft industry
fought back, challenging the findings, appealing to federal officials, and alleging that Tobin
might be corrupt. After two years of conflict, the airplane industry capitulated, and in a few
years the standards developed for the New York airports were embraced by airport managers
across the United States and Europe.

This paper summarises the battle that ensued between the Port Authority and the airlines,
leading to the development of noise limits for operations at the New York airports during the
early days of jet travel.

1. Introduction

By the mid-1950s, residents living near airfields in the United States began to complain about
the level of noise, as an increasing number of propeller-driven planes took off and landed in
their neighbourhoods. Those living near Newark Airport filed a lawsuit, and at New York's
Idlewild Airport (now JFK), there were threats that "if the noise . . . increases, mothers with
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1
baby carriages would go "onto the runways". Adding to the tension, in 1956 Pan American
Airways asked for permission to fly a jet-powered plane, the Boeing 707, at Idlewild.

The Port Authority of New York & New Jersey 2 operated the Newark and Idlewild airfields,
as well as LaGuardia, as it does today. The executive director of the Port agency, Austin
Tobin, was concerned that jet aircraft might be noisier than propeller-driven planes, but
Boeing assured Tobin that a jet plane, as measured by Boeing's sound monitors, generates no
3
higher noise levels than a propeller plane of the same size. Wary of Boeing's claim, Tobin
and his aides decided to monitor the 707's noise level. Some background on the Port
Authority and Tobin will be helpful at this point and is provided below.

2. An Unusual Public Agency and its Exceptional Leader

The Port Authority (PA) had been created in 1921 through a formal compact between the
states of New York and New Jersey that established a Port District encompassing New York
City, portions of Long Island and Westchester County, and parts of nine counties in New
Jersey. The Port Authority was designed to provide an unusual degree of independence for
its officials. The agency was controlled by six commissioners, three appointed by each state
governor for six-year terms, thus signalling that they could serve beyond the shorter terms of
the appointing executives. Moreover, the PA was required to finance its activities from rents
and tolls, so the state legislatures could not use the threat of withholding appropriations to
bend the agency to achieve narrow political goals. In addition, the commissioners were
expected, under terms of the 1921 treaty, to act in ways that would benefit the entire bi-state
region, rather than focusing on short-term political benefits for the appointing governor or
4
their own state.

Austin Tobin, born in Brooklyn in 1903, graduated from the College of the Holy Cross,
Worcester, Massachusetts, in 1925 and joined the staff of the Port Authority in 1927, while
completing work on a law degree. Tobin signed on to the agency as it was completing

1
John Wiley, the Port Authority's Director of Aviation, as quoted on page 2 of Beranek (2004).
"Idlewild" was the name of the golf course replaced by the new airfield, and "Idlewild" became the
airport's informal but widely used name until 1963, when it was named John F. Kennedy International
Airport. From 1947 to 1963, its official name, rarely used, was "New York International Airport".
2 The title of the agency was changed in 1972 from Port of New York Authority to Port Authority of
New York and New Jersey, to better reflect the equal status of the two states in governing the agency.
3 Austin Tobin, Nov. 8, 1956, as cited in Beranek (2004), p.2.
4
Doig, 2001, chapter 3. In the 1920s, New York governors had two-year terms and New Jersey
governors three-year terms. In 1927, the two governors were given the power to veto actions of the
PA, and in 1930 the number of commissioners was increased to six from each state.
Those who have followed the Port Authority's recent sad history will know that New Jersey's current
governor, Chris Christie, appointed commissioners and patronage-linked staff members who misused
their powers; in several cases, they were removed from the agency and found guilty of criminal
behaviour (see Amanda Terkel, “Top Christie Aides Found Guilty of All Charges in Bridgegate
Scandal" Huffington Post, Nov. 4, 2016). In the earlier era examined in this essay, the agency and its
leaders were largely free from that kind of political incursion.
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several major projects - three toll bridges connecting New Jersey and Staten Island, and the
George Washington Bridge, which opened in 1931. In 1930-31, the PA also took control of
the Holland Tunnel, which had been built by another bi-state body. The PA's hopes for a
large influx of funds from bridge-and-tunnel revenues were sharply diminished by the
Depression, and the agency was only able to undertake a few projects, notably the first tube
of the Lincoln Tunnel. However, Tobin used his position on the legal team to take a
dominant role in combating Franklin Roosevelt's attempt to eliminate tax-exempt bonds.
Successful in beating FDR, Tobin won the admiration of most PA commissioners, and in
1942 he was appointed Executive Director; it was a position he would hold for nearly 30
5
years.

With the agreement of the PA Board, Tobin recruited a talented staff to identify needed
projects in the region and once World War Two was over, Tobin was ready to extend the
PA's reach beyond bridges and tunnels. Gasoline rationing ended in 1946, and the Port
Authority began receiving millions of dollars a year, mainly from tolls on the George
Washington Bridge, the Holland Tunnel, and the Lincoln Tunnel (whose first tube opened in
1939). Tobin persuaded the PA commissioners to approve a range of major projects - a
massive bus terminal in Manhattan, marine terminals that could be acquired or built on both
sides of the Hudson, and the take-over and modernization of all the major airports in the
region. By 1946, the entire PA Board supported expansion into new fields, and they deferred
to Tobin and his executives in deciding on the steps needed to carry out these projects.

3. Working with the airlines.

The PA's leaders faced several challenges in their efforts to win control of the region's major
airports - Newark, LaGuardia, and Idlewild.6 Newark's elected officials resisted turning over
their airport, and in response Tobin announced a plan to invest $55 million in modernizing
the field; he also promised to provide the city with millions more, in lieu of taxes. With
Newark's leaders still reluctant, Tobin then enlisted the New Jersey State Governor, who
suggested that rejecting the PA's offer might jeopardize substantial state aid to the city.

Across the Hudson, Tobin faced resistance not only from New York City's mayor but also
from Robert Moses, who had persuaded state officials to create a "New York City Airports
Authority", to be controlled by Moses's appointees. Tobin challenged the Moses scheme,
explaining to Juan Trippe (founder of Pan American World Airways), Eddie Rickenbacker
(General Manager of Eastern Air Lines from 1935 and owner and President from 1938) and
other airline executives that the Port Authority could use millions from its toll revenues to
modernize and expand LaGuardia and Idlewild facilities; he expressed doubt that the new
Moses creation would have the funds needed to modernize those airfields. Tobin also
contacted Eugene Black, a prominent banker he knew from the 1930s battles on tax-exempt
bonds. Black then called the Mayor and told him that the Moses agency could never raise the

5 Doig, 2001, chapters 9 and 10.
6 On the complex airport negotiations described below, see Doig, 2001, chapter 11, and Nicholas
Dagen Bloom, 2015, chapter 1.
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money needed to achieve the airlines' expansive needs. Tobin played the two sides against
each other, arguing to New York officials that Port Authority investment in Newark could
make that city the region's premier landing site; to Newark leaders he pointed out that their
airport would soon lose to New York in the battle for regional eminence - unless PA was
permitted to lease Newark Airport and invest heavily there. By the fall of 1947, Newark and
New York City had both succumbed, signing over control of the three airports to the Port
7
Authority.

3.1 The airlines challenge Tobin

Trippe, Rickenbacker, C. R. Smith (President of American Airlines) and their fellow airline
executives had fought actively - in the press and behind the scenes - in support of the Port
Authority's take-over plans. Their efforts were motivated in part by their expectation that the
Port agency would be able to modernize the airports far more quickly than the cities, whose
leaders faced heavy demands in the early post-war years to invest in new schools, roads, and
other facilities. However, the airlines' strong support for the PA option at Newark, LaGuardia
and Idlewild was also shaped by a second, very important reason: Tobin had told them that he
would not try to increase the rates the airlines were paying to use the airports. In 1944-45,
the airline executives had persuaded Mayor Fiorello LaGuardia to grant them very favorable
lease rates, extending for 40 years, as a way of enticing them to move their maintenance and
other operations from Chicago to New York. A preliminary review suggested to Tobin that
the charges levied on the airlines under those leases - for landing and taking off, and for use
of airport hangars - were adequate to permit the airports to break even, in the long run. His
staff had developed plans to include bookstores, restaurants, and other activities that would,
they felt sure, provide a substantial funding base for airport financial success.

Once the Port Authority had taken control of the three airports and analysed the lease rates
more closely, Tobin and Wiley realized they were probably too low to allow the airports ever
to be self-supporting. They explained this to the airline executives and said the rates had to
be increased, but Trippe and his colleagues resisted any change in the lease rates and
appeared confident they could win this battle. As one airline official commented later:
"The airline executives thought he [Tobin] didn't know what league he was batting in.
8
He would be no match for an aggravated Rickenbacker or C.R. Smith."

But they misjudged Tobin, who responded aggressively to the executives' resistance. First,
he arranged to discuss the airline situation with several business groups in the New York
region, and there he outlined the Port Authority's plans to spend millions to modernize the
three airfields, including new hangars and passenger buildings; however, since these new
facilities were not included in the "LaGuardia leases" (which focused on landing fees and

7 The final negotiations are described in Doig, 2001, pp.272-281.
8 Robert W. Tuttle, American Airlines official in the 1940s, letter to the author, May 31, 1984. The
conflict with the airlines regarding leases as summarized below is discussed at greater length in Doig,
2001, pp.292-312 and 513-524. For a brief review, see Bloom, 2015, pp.33, 35, 41-44.
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existing hangars), they would only be available to airlines that agreed to new leases with
higher rates. Second, he offered "preferred choice of space" to several foreign-flag airlines
that were not bound by the leases negotiated by the American carriers. And third, he
contacted the directors of the largest airports in the U.S. and urged that they join forces in
pressing the airlines to accept higher lease rates. They readily agreed, since all believed their
deficit-generating airfields needed increased funds from airlines, and early in 1948, they
created an "Airport Operators Council" to generate nation-wide counter-pressure against the
airlines. The airlines had their own national organization, the Air Transport Association of
America (ATA) (now Airlines for America [A4A]), which included all the major U.S.
carriers; the ATA set policies nationally on lease rates and other issues. Tobin's staff went to
the press with their concerns, leading the New York Times and the Wall Street Journal to
endorse the Port Authority argument that the airlines should pay higher fees.

The U. S. carriers countered by creating a boycott of Idlewild, which they asserted would be
maintained until the Port Authority agreed to abide by the LaGuardia leases at all the PA's
airfields. Then, when it was learned that foreign-flag carriers were planning to move their
operations from LaGuardia field to Idlewild, the ATA sent out information suggesting that
conditions at Idlewild were "unsafe". And when the Port agency issued new bonds,
undergirded by bridge and tunnel tolls, to finance improvements at the airports, the ATA
allegedly spread rumours indicating that those bonds were not a sound investment. Finding
the Port Authority unmoved, the airline executives filed suit against the PA commissioners
and against Austin Tobin, and they appealed to New York Governor Thomas E. Dewey to
intervene on their behalf. 9

3.2 Dewey enters the fray

Exhausting negotiations followed. On July 21, 1949, Governor Dewey brought together
Rickenbacker, Trippe, C. N. Smith and the PA Commissioners, plus Tobin and his top aides,
to discuss the lease issue; he said he wanted the problem resolved quickly. No real progress
was made after several hours, so he scheduled another meeting for July 29. That one lasted
13 hours and produced no agreement. But Dewey announced that progress had been made
and that a final agreement would be achieved at a meeting set for August 4. By now Dewey
had modified his position, essentially agreeing with the Port Authority that the airlines must
pay much more for use of the New York airports, so the PA would have the money needed to
turn Idlewild into a first-class airfield. Even so, Dewey's third meeting took 23 hours. At the
end of that marathon, Trippe and his fellow executives agreed to sign new leases that would
levy much higher charges on the airlines.

9 The airlines thought they had Dewey in their corner, as indicated in a memorandum summarizing
his views as he entered the fray in July 1949: "He thought it was a public scandal for the Port
Authority to follow such a policy of harassment . . . that the airlines which were being harassed were
headed by outstanding businessmen and that they had valid leases which should be honored" (Port
Authority, Memorandum regarding events leading to the Agreement, July 1949, p.2; quoted in Doig,
2001, p.521).
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Announcing the formal Agreement (now it was August 5), Dewey spoke with enthusiasm: "I
believe," he said, "the rest of the country will follow the pattern of our airport agreement."
And so it did, facilitated by the AOC, and much to the chagrin of Rickenbacker, Trippe and
C.R. Smith.10 It would be incorrect to count this as a defeat for the airlines. In the short run,
the agreement signed by Dewey and largely adopted across the nation meant that the airlines
would pay more - and that local taxpayers, often resistant to funding airfield improvements,
would be much less burdened and less aggrieved. The agreement "actually proved valuable
in the long term for airlines and the aviation industry", as Nicholas Bloom (2015) concludes,
for it provided funds that airport managers then used to modernize and expand the airfields in
New York, Newark, Denver, and dozens of other cities.11 But the battle over the leases gave
Tobin a very unfavourable view of the values and behaviour of the airline industry.

4. Jet Aircraft Noise and the Tobin-Beranek Alliance

We turn now to 1956; seven years have passed since the lease issue was resolved. The
airlines were paying much larger fees to use the airports, yet their business was booming.
The Port Authority used the extra funds to turn Idlewild into a first-class facility and to make
substantial improvements at LaGuardia and Newark. On the down side, the noise from
increasing airline takeoffs and landings was generating growing opposition in the communities
12
under the major flight paths. And Tobin had not shaken free from the negative attitude
toward the airlines that had been engendered by the battle over lease fees. Meanwhile, jet-
propelled planes had been developed and tested. Compared with propeller-driven airplanes,
they were faster, and they offered great savings in fuel cost. Airline executives were
enthusiastic, and in the fall of 1955, Pan American Airways committed to purchasing 20 jet
planes built by Boeing. Pan Am expected to use the Boeing 707 for commercial flights from
New York to Europe, beginning in the fall of 1958. American Airlines soon followed with an
13
order for 30 jet airliners from Boeing.

When they alerted Austin Tobin and John Wiley to their plans, Pan Am officials said that
Boeing had tested the new plane using its sound monitors, and that jets were no noisier than
propeller driven planes. However, the lease negotiations had left Tobin with a very sceptical
view of the airline executives; he did not trust them, and he decided the Port Authority should
conduct its own tests before permitting jet planes to use its three airfields.

10 "Idlewild Dispute is Ended on Terms Drawn by Dewey," New York Times, August 6, 1949; "Of
National Significance" (editorial), Newark News, August 7, 1949.
11
Bloom, 2015, pp.43-44.
12
"In the area around Idlewild, the loud buzzing of propeller aircraft was so distinctive, so close, and
so frequent that even the most elite and bucolic suburbs, housing their fair share of air travellers, rose
up in protest" (Bloom, 2015, pp.56-57). It is worth noting that the original versions of the Boeing 707
used pure turbojet power plants. These noisy engines were later replaced by quieter models that
employed bypass and turbofan technology.
13
Richard Witkin, "45 Jets Ordered by Pan Am: Cost $269,000,000," New York Times, October 14,
1955; George Horne, "30 Turbo-Jet Airliners Ordered by American for Use in Mid-1959," New York
Times, November 9, 1955. (Pan Am also ordered DC-8 jets from Douglas.)
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Tobin had a habit of seeking out experts who could provide an independent analysis of
complex problems faced by his agency. In 1946, for example, he had located a nationally
prominent planner who reviewed the Port Authority's plans for Newark Airport, and he had
consulted with experts at the Regional Plan Association in analysing the pros and cons of
combining the three major airports under one manager (the Port Authority). Now, working
with his aviation director, John Wiley, a graduate of MIT, Tobin sought an independent
expert who could test Boeing's assertion on jet noise levels, and he soon fixed on Leo
Beranek.

5. Beranek of MIT and BBN

Leo Beranek was born in Solon, Iowa in 1914. He attended Cornell College in Iowa, where
he became interested in radio technology; while an undergraduate, he designed and installed a
complex antenna system for radio reception in a dormitory at the College. Graduating in
1936, Beranek was accepted for graduate work at Harvard and completed a PhD in
engineering in 1940.14

When the United States entered World War Two, Beranek was placed in charge of the
Harvard laboratory that designed noise-reduction systems used by U.S. aircraft. In 1947, he
joined the MIT faculty, and a year later he and two other engineers created the firm Bolt,
Beranek and Newman (BBN) to work on acoustics problems. In 1954, Beranek published
Acoustics, which soon was viewed as a classic textbook in the field.

5.1 Tobin calls

On November 7, 1956, as Beranek later recalled, "I was sitting in my office . . . when I
received a telephone call from Austin Tobin". Tobin said he was the director of the Port of
New York Authority, which is "facing a very serious noise situation and we have to deal with
it reasonably fast. We'd like to talk with you about it". 15 Beranek said he could not leave for
New York at once, since he had to teach a class at MIT the next day. But he agreed to take a
plane after class to LaGuardia, and there he transferred to a PA helicopter, which landed atop
the PA building at 14th Street and 8th Avenue.

At the November 8 meeting, Tobin explained that "Pan American Airways has asked for
permission to begin jet aircraft operations from Idlewild Airport in November 1958". A new
jet-propelled passenger airplane, called the Boeing 707, would be used, and "we must know
how noisy it is". Tobin pointed out that the PA faced a lawsuit at Newark Airport, brought
by residents complaining about noise from propeller-driven airplanes. Wiley then noted that
a few years earlier "we told the airlines that a jet plane must make no more noise that a large

14 This summary of Beranek's early life is drawn from his autobiography, Riding the Waves: A Life in
Sound, Science, and Industry, chapter 1-5 (Beranek, 2008).
15 Beranek (2004), p.1. The 2004 paper was later modified to form chapter 6 in Beranek, 2008.
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propeller airplane on takeoffs and landings; the maximum set was 112 decibels. Boeing
claims they have met this requirement", for their sound-level meter shows "the same number
of decibels of noise from the jet plane during flyover as from a Super Constellation propeller
plane." But we need, Wiley concluded, an independent assessment of the noise level. Beranek
agreed to take on the task. "The first step would be for Boeing to make flyovers, so we could
measure the noise." 16 It was, as Beranek later commented, an unusual strategy. "Regulation
of flight profiles by an airport operator was unheard of" and the effort would be "intensely
resisted both by the airline/aircraft industry and the FAA (Federal Aviation Agency; in 1956,
this was the Civil Aeronautics Administration (CAA))." 17

6. Boeing fails the first test

Tobin contacted Boeing, which had retrofitted a military jet tanker plane to serve as a
passenger aircraft (the Boeing 707). The test was conducted at Boeing's headquarters in
Seattle, and the plane flew about 1,000 feet overhead (about the same height as planes at
Idlewild when they flew over nearby houses), with Beranek, Tobin, and Wiley below. As
18
Beranek recalled, "We were stunned - the noise was terrible, unbelievable." Tobin
concluded that his agency "will not approve the use of our airport by a plane this noisy" and
so informed the Boeing staff. "They bristled at this," since the jet plane and the propeller-
19
driven plane measured the same on their sound-level meter. How could one sound much
louder to the human ear?

Here Beranek's acoustical expertise provided the answer: A propeller plane has its loudest
noise in the low-frequency range, 50-200 Hz, while the jet's loudest noise occurs in the range
of 500-2,000 Hz. One hertz is defined as one cycle per second, and the sound meter measured
the sound energy, without regard to whether it was at high or low frequency. However, the
human hearing mechanism is "many more times more sensitive to high- than to low-
20
frequency noise".

16 Beranek, 2008, p. 126. The Port Authority-BBN teamwork is briefly summarized in Bloom, 2015,
pp.86-88. For a useful overview of the noise issue as it evolved, see Alexis Faust and Dina Taylor,
"Aircraft Noise, 1948-1972," October 1986 (an essay prepared for J.W. Doig and available in the New
Jersey Archives, Doig files).
17 Beranek letter to Seymour, Jan. 5, 2004, p.1.
18
Beranek, 2004, p.3. As Nicholas Bloom recalls the experience of living under the Idlewild flight
path;it meant "skies, backyards, and living rooms filled with the din of shrieking jet engines" (Bloom,
2015, p.85).
19 Beranek, 2008, p.127.
20
Beranek, 2004, p.3. His autobiography (2008, p. 127) refers to the two ranges as "50 to 2,000 hertz"
and "500 to 2,000 hertz"; this is almost certainly a typo, and I have used as accurate the ranges in his
2004 paper. As Jay Buckey comments, “the Boeing measurements showed that the total sound energy
was the same” for prop and jet planes, but they failed to “take into account how the human ear
perceives sound” (message to J. Doig, Oct. 1, 2017).
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7. Measuring noise as heard by the human ear

The next step, Beranek and Tobin agreed, was to conduct a series of tests that might indicate
what level of jet takeoff and landing
noise would be acceptable to those
living below the flight path. The Port
Authority agreed to finance this
exploration, which would begin in
December 1956 and be conducted by
Beranek's firm, Bolt-Beranek-Newman
(BBN). BBN set up test locations in
residential areas near Idlewild Airport -
mainly between two and three miles
from the start of takeoff roll - and the
firm installed cameras (to determine the
height of the flight at each location)
plus magnetic tape recorders (to capture

the sound level). Takeoffs of the Super
Figure 1 Lockheed L-1049 Super Constellation
Constellation (Figure 1) and other large
National Aerospace Library, RAeS
planes were monitored. The result was a
series of measurements taken at various
21
times of day that described "what noise levels neighbours were experiencing."

With the recordings of noise from propeller planes at Idlewild in hand, BBN then went to the
Seattle airport where, in January 1957, Boeing agreed to fly 707s - fully loaded, using lead
bars as ballast - into and out of the airfield. The evening before the tests began, "Boeing tried
to put us in a good mood by hosting a lavish diner". In view of Tobin's known hostility
toward the airline executives, described above, one should not have expected that the tactic
would be successful. 22

Boeing engineers and BBN staff took measurements from standard sound meters as well as
recordings on magnetic tapes. Now the challenge was to use the Idlewild and Seattle findings
in a way that allowed BBN and Tobin to determine what level of jet noise (from the Seattle
monitors) felt no worse than the noise level generated by large propeller aircraft (as measured
at Idlewild).

Tobin and Beranek agreed that the propeller-driven plane most similar in size to Boeing's 707
was the Lockheed Super Constellation, which Boeing had used in its initial noise comparisons.
BBN had recently hired Karl Kryter, an experimental psychologist, and he brought several of

21 Beranek, 2008, p. 128. The discussion below is drawn mainly from this source, pp. 128-134.
22 At the dinner, "we were told how much the new plane meant to the company and how it was certain
to open up a new world of commercial travel. The journey by air from California to New York, they
boasted, would be cut from eight hours down to six. But these lobbying tactics made little impression
on the Port Authority people, who remained skeptical and content to await analysis of the test results"
(p.128).
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Journal of Aeronautical History Paper No. 2017/03
the firm's engineers and secretaries into a room outfitted with loudspeakers. The flyover
noises from the Lockheed prop plane and the Boeing 707 were adjusted so they would be
heard "as if inside a typical home, in summertime, with open windows". The subjects were
asked to use a knob to adjust the flyover noise from the jet planes, as taken from the tape
recordings, so it was no noisier than the prop noise. The same test was conducted with three
other groups, using somewhat different instructions. 23

The results provided a stunning confirmation of the difference between measurement using a
sound-level meter and the human hearing mechanism. If the noise levels of the 707 jet were
to be no more disturbing than the noise levels of the Lockheed propeller plane, the 707 noise
level would have to be "reduced by more than 15 decibels. This was, Beranek concluded,
"tantamount to reducing the noise made by 30 jet engines to that made by a single engine"! 24

Tobin took this unwelcome news to Boeing. Boeing then sent several staff members to New
York to take the same comparison test, which convinced them that further efforts to reduce
noise were essential. The firm agreed to develop "the best mufflers that they could conceive
of" to attach to the jet exhausts; they hoped this would solve the jet-noise problem.25

8. Noise reduction: the 112 PNdB goal

Meanwhile, at BBN, Dr. Kryter devised a new unit of measurement for determining the level
of noise as humans encountered it - the perceived noise level in decibels or PNdB. The
propeller-aircraft noise data recorded during months of measurements - at various distances
from the end of JFK runways - are displayed in terms of PNdB in Figure 2. As the graph
shows, when the planes passed over the nearest houses (2.5 miles on the graph below), 25%
of the flights exceeded the goal of 112 PNdB, the maximum noise level Tobin and his aides
26
would permit.

As Nicholas Bloom comments, "this standard revolutionized the field of noise pollution by
27
significantly raising the bar for aircraft operators and manufacturers."

The airline industry refused to accept the 112 PNdB standard, but Tobin and his aides held
firm. "The Port Authority needed jets to pay its bills," Bloom notes, "but it also had a lot to
lose if neighbours revolted successfully. In New York's often volatile political arena, even a
seemingly powerful and independent agency such as the Port Authority had to negotiate with

23 Beranek, 2004, p.4.
24 Beranek, 2008, p.129.
25 Beranek, 2004, p.5.
26 The nearest residences to the airport were in Howard Beach, about 2.5 miles from the start of
takeoff roll (The graph is included in the 2004 paper, but not in Beranek's 2008 autobiography.)
27
Bloom, 2015, p.86. "Perceived noise level measured in PNdB became the rating adopted
internationally for measuring aircraft noise. It continues to be used today in certification of airplanes"
(Carl E. Hanson, "Leo Beranek's Contributions to the Field of Transportation Noise," Acoustics
Today, Fall 2014, p.33).
34