EPA-AA-AC 76-04
Technical Support Report for Regulatory Action
SST Emissions Projection
June, 1976
Notice
Technical support reports for regulatory action do not necessarily
represent the final EPA decision on regulatory issues. They are in-
tended to present a technical analysis of an issue and recommendations
resulting from the assumptions and constraints of that analysis. Agency
policy considerations or data received subsequent to the date of release
of this report may alter the recommendations reached. Readers are
cautioned to seek the latest analysis from EPA before using the infor-
mation contained herein.
Standards Development and Support Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Office of Air and Waste Management
U.S. Environmental Protection Agency
-------
Abstract
This document details the derivation and estimate of the emissions
from both subsonic and supersonic commercial aircraft at John F. Kennedy
International Airport in 1990. The estimate includes two scenarios, one
presuming there are no standards, the other presuming implementation of
all existing standards and the T5 class standards recommended in "Alter-
native Derivations of the Standards for T5 CSupersonic Transport) Class
Gas Turbine Aircraft Emissions," EPA Technology Support Report, AC-76-
01. This estimate draws from several sources, principally FAA terminal
passenger projections, FAA fleet type projections, and manufacturers'
engine data. As the FAA information does not extend beyond 1985, this
estimate has had to rely on certain extrapolations in order to reach the
desired 1990 situation.
The projection shows that the emissions standards for subsonic
aircraft (classes T2, T3, T4) have a significant impact on aircraft
emissions at JFK in 1990. The projection further shows that if there
develops a moderate sized fleet of SST aircraft (150 by 1990), then
the T5 class standards recommended in EPA Technology Support Report,
AC-76-01, will substantially reduce further the emissions of hydro-
carbons and carbon monoxide. The T5 class standards
have little effect on the emissions of oxides of nitrogen.
Prepared by:
Richard W. Hunt, SDSB
Approved by:
W. Houtman, Program Manager,
Aircraft
Approved by:
Charles Gray, Chief/ SDSB
Approved by:
John P. DeKany, Directop7
EGTD
Distribution:
-------
Introduction and Summary
The preamble to the draft T5 class (SST) emissions regulations
contains a table shown below which estimates the contributions of the
subsonic fleet and the supersonic fleet to the air pollution load at
John F. Kennedy Airport in New York in 1990. The table further assesses
the impact of both the subsonic and the supersonic emissions regulations
by presenting pollution load scenarios both with and without these
regulations in effect.
This table differs somewhat from that presented in the preamble of
the Notice of Proposed Rulemaking for the T5 class emissions standards
(FR Vol. 39, No. 141, July 22, 1974, p. 2665-4) owing principally to new
estimates of the size and distribution of both the subsonic and supersonic
fleets (distribution includes both aircraft type as well as the level of
compliance with the standards).
This document explains the derivation of the numbers quoted in
Table I. This derivation involves far more than reference to a published
estimate of the distribution of type and compliance level of aircraft at
JFK in 1990 and application of that estimate to the emissions figures
implicit in the respective levels of compliance. First, the distribution
of type and compliance level of aircraft is not available from any
published source. Rather, the work of this document has been to draw
from several relevant sources of different kinds of data, make hopefully
reasonable assumptions plus.some arbitrary hypotheses, and arrive
independently at.an. estimate of the size and distribution. Secondly,
the typical landing-takeoff (LTD) cycle at JFK differs from the LTO
cycle specified in the EPA standards. Hence the standards alone do not
offer enough information to predict individual aircraft emissions by
type and level of compliance. Hence, adjustments must be made to levels
predicted by the standards in order to describe emissions at this
particular airport. Of course, the assumption that the present LTO
cycle at JFK will be similar to that experienced in 1990 is certainly
arbitrary, but is as equally defensible as any other guess.
It should be recognized that often the final result is not terribly
sensitive to the assumption in question. While error bands were not put
into the analysis, the skeptical reader is advfsed to check for himself
the sensitivity of the result to a reasonable departure from an assumption
which is in question. The important point is that this impact analysis
seeks only to (1) compare the relative importance between the subsonic
(T2, T3, T4 classes) standards and the supersonic (T5 class) standards
and (2) offer a rough idea of the magnitude of the aircraft pollution
load. The first goal can be reasonably well met regardless of the
precise accuracy of many of the assumptions. Table I, in fact, shows
rather strongly that T5 standards for hydrocarbons (HC) and carbon
monoxide (CO) are an important contribution to the overall aircraft
picture (at an international airport such as JFK, at least) despite the
relatively few SST aircraft in 1990, about 70 U.S. SSTs versus 3500 U.S.
subsonic jet aircraft and a comparable ratio for foreign aircraft. The
table also emphasizes the unfortunate fact that despite the large impact
-------
-2-
TABLE I
Emissions Impact of Supersonic Transport Aircraft at
John F. Kennedy Airport in 1990
(Tons per year)
, HC CO NOx
Uncontrolled subsonic aircraft emissions- 3,300 7,950 3,200
Uncontrolled supersonic aircraft emissions--2,100 7,850 1,050
Total uncontrolled aircraft emissions5,400 15,800 4,250
Reduction in aircraft emissions due to
standards for subsonic aircraft only 1,900 3,700 950
;, Percent_reduction from uncontrolled
fleet 35 23 22
Reduction in aircraft emissions due to
standards for supersonic aircraft only 1,300 3,950 150
Percent reduction from uncontrolled
fleet . 24 25 4
Reduction in aircraft emissions due to
standards for both subsonic and supersonic-
aircraft > -3,200 7,650 1,100
Percent reduction from uncontrolled
fleet . 59 48 26
Note: (1) Estimate: 150 SST aircraft in world fleet; 50 LTOs per
day at JFK.
(2) JFK taxi-in and taxi-out modes are 9 minutes and 20
minutes respectively.
-------
-3-
of SSTs in the oxides of nitrogen CNOx) picture, the SST standards do
very little to improve it, largely because of the lack of effective NOx
control reflected in the T5 newly manufactured engine (ME) standards.
In addition, the relatively large. HC and CO output from the T5
class even with the regulations imposed on them indicates a possible
need for a retrofit requirement for T5 class engines built before the
compliance date for NME.
Discussion
The derivation of the emissions from aircraft at JFK in 1990 (what
is presented in Table I) requires knowledge of:
I. The aircraft usage (numbers and types) at JFK in 1990.
II. The emissions from each type, including a distinction between
the different levels of compliance.
The discussion below is divided according to these separate analyses:
I. Aircraft Usage at JFK in FY 1990.
The steps involved here are:
1. Estimate the passengers (PAX) departing JFK in 1990;
2. Estimate the passengers on foreign carriers (international
flights only), U.S. carriers (domestic and international
flights), supersonic aircraft, and subsonic aircraft (by type,
e.g., short haul domestic, etc.);
3. Estimate freight;
4. Calculate the number of LTOs performed by each type in order
to accomplish the necessary passengers and freight carriage.
Reference 1 indicates 16,763,000 passengers at JFK in FY 1986, the
furthest projection available from the Department of Transportation.
Projecting the 1985-1986 growth rate (2.04% per annum) for the next four
years gives an estimated 18,173,000 passengers in FY 1990, the answer
required by step 1 above.
References 2 and 3 show that U.S. carriers at JFK served 4,556,000
domestic and 2,869,000 international passengers (7,425,000 total) in CY
1973 and 4,381,000 domestic and 2,544,000 international passengers
(6,925,000 total) in CY 1974. Averaging these calendar year figures
gives a good approximation for FY 1974:
U.S. Carriers - domestic 4,469,000
international 2, 706,000
total 7,175,000
-------
-4-
Reference 1 further cites that the total passengers for FY 1974 at JFK
were 10,034,000, the difference, 2,859,000, being attributable to foreign
carriers, all of which were international. For FY 1974, then,
U.S. Carriers - 7,175,000 71.5%
domestic - 4,469,000 44.5%
international - 2,706,000 27.0%
Foreign Carriers (international) - 2,859,000 28.5%
Total International 55.5%
Domestic 44.5%
For a lack of a better defined position it will be assumed that
these percentages apply also to the FY 1990 data. Applying these ratios
to the 18,173,000 passengers predicted at JFK for FY 1990 gives:
U.S. Carriers: 12,995,000
international - 4,808,000
domestic - 8,187,000
Foreign Carriers: 5,178,000
Total 18,173,000 (1)
Total International . . . 9,986,000
Domestic 8,187,000
This resolves step 2.
Reference 3 states that in FY 1974 450,600 tons departed JFK on all
carriers, but reference 3 and 4 together show that only 392,400 tons
could have been carried on U.S. freighter aircraft so the remainder was
evidently carried aboard either U.S. passenger aircraft or foreign
aircraft, either freighter or passenger. This implies that up to 87% of
the cargo business was carried aboard U.S. freighter aircraft in 1974
and it is assumed in this report that that percentage will also apply in
1990.
Assuming, arbitrarily, a 5% growth in freight to 1985 and a 2%
growth thereafter, then in 1990, 682,000 tons will depart JFK and 87% of
that, or 594,000 tons, will be hauled aboard U.S. carrier freighters.
The remaining 13% is carried aboard U.S. or foreign passenger craft or
foreign freighters. As no data are available to predict what fraction
of the 13% might be carried aboard foreign freighter aircraft (thereby
adding to the number of LTD cycles at JFK), it is assumed for simplicity
that all the remaining 13% is carried aboard passenger aircraft so there
is no increase in the LTD cycles. This completes step 3.
In order to calculate the number of LTOs per year performed by each
aircraft type, the following assumptions are made:
-------
-5-
1. All freighters are 4 engine jumbo types.
2. All freighters operate full.
3. 4 engine jumbo types are not used domestically for passenger
carriage by the U.S. fleet.
4. 4 engine narrow body types are absent from the U.S. fleet.
5. 10% of the foreign fleet are 4 engine narrow body types.
6. 2 and 3 engine narrow body types are not used internationally.
7. 2 engine jumbo types are in the foreign fleet only.
8. 3 engine super stretch types are used only by the U.S. fleet
and are used domestically and internationally.
9. Load factor is 70% for passenger hauling.
10. SSTs are used on international flights only.
Examples of the aircraft types referred to above are:
2 engine narrow body - DC-9, B737
3 engine narrow body - B727
4 engine narrow body-- B707", DC-8
3 engine super stretch - B7X7*, B7N7*
2 engine jumbo - A300, DC-X*
3 engine jumbo - DC-10, L1011
4 engine jumbo - B747
SST - Concorde, AST**
Freight Requirements
From reference 4 and the estimated freight to be shipped (594,000,
see discussion of step 3), the number of LTD cycles per year in 1990 is:
594,000 x 2000 ,._. T_nl . _.
166,750 = 7124 LTO?s/year C2>
Passenger Requirements
Consider first the supersonic international flight by both U.S. and
foreign carriers. It is hypothesized that there are 50 LTOs/day by SST
type aircraft and further that the worldwide fleet of 150 SSTs include
* This aircraft is not yet in production nor fully defined.
** AST = Advanced Supersonic Transport (Not yet in production nor fully
defined).
-------
110 Concorde type aircraft and 40 ASTs. Assuming that the 50 LTOs per
day also reflect this distribution, then there are 37 Concorde LTOs and
13 AST LTOs per day at JFK in 1990.
Annually, this means:
Concorde type: 13,505 LTOs./year
AST: 4,745 LTOs/year (3)
The use of SSTs will mean, of course, fewer people to be carried on
the subsonics and thus fewer subsonic LTOs per year. The passengers carried
by SST aircraft are:
Concorde: 13,505 x 120 x 0.7 = 1,134,000
AST: 4,745 x 250 x 0.7 = 830.000
1,964,000
where 0.7 is the load factor (as assumed). The full Concorde capacity
of 120 is expected (reference 5), and the AST capacity is here assumed
to be 250 (reference 6) .
If the SST passenger (PAX) distribution follows the total inter-
national PAX distribution between U.S. and foreign carriers (.see (1))
then
IT.S. Carrier SST PAX = 946,000-
Foreign Carrier SST PAX = 1,018,000 ^ '
1,964,000
This leaves for subsonic (M<1) international flight, from (1) and (3),
U.S. carrier M<1 PAX = 3,862,000
Foreign carrier M<1 PAX = 4,160,000 (4)
The international subsonic aircraft LTOs are next calculated on the
basis of the remaining passenger requirements. To this end, the subsonic
LTOs for U.S. carriers and foreign carriers are considered separately.
U.S. Carriers -
It is first necessary to estimate the distribution of LTO's by
different aircraft types at JFK in 1990. From reference 3, in 1974 at
JFK, U.S. carriers used on international flights,
3 engine narrow body: 2316 LTOs/year
4 engine narrow body: 9612
3 engine jumbo: 2083
4 engine jumbo: 5995
-------
-1-
The ratio of these types will be used for the 1990 computation with cer-
tain differences assumed. Consistent with the assumptions listed on
page 5, the 3 engine narrow body will be replaced by the 3 engine super
stretch for international flights. As the new aircraft has a seating
capacity of 190 versus 130 for the older plane, the 2316 LTOs/year for
1974 would become effectively:
7 3D
2316 x ~ = 1585 LTO's/year
if the new plane had been in use in 1974. Also consistent with the
earlier assumptions is the replacement of the 4 engine narrow body types
by 3 and 4 engine jumbos (190 seats vs. 380 and 400 seats, respectively).
Arbitrarily assuming that the passengers of the older aircraft are
divided equally among the two newer types, then the additional LTOs/year
of the newer types in 1974 resulting from a replacement of the 4 engine
narrow body type are:
A 3 engine jumbo = 9612 x -|~ x -| = 2403
and
A 4 engine jumbo = 9612 x ||| x y = 2283
Therefore,- the 1974 LTO picture for U.S. carriers on international
flights with a hypothetical 1990 style fleet (i.e., types in service)
wouid be .
3 engine super stretch: 1585 LTO's/year (11.0%)
3 engine jumbo: 4486 LTO's/year (31.3%)
4 engine jumbo: 8278 LTO's/year (57.7%)
(100.0%)
As stated above, these ratios of types will be used to represent
the distribution of LTOs among the aircraft types for international
flights by U.S. carriers. In 1990, from (4), the U.S. carriers will
move 3,862,000 passengers from JFK on subsonic international flights.
The total number of LTO's needed to do this (N) is:
NX (.11 x 190 x .7 + .31 x 380 x .7 + .58 x 400 x .7) = 3,862,000
where 0.7 is the load factor, the ratios are as above for each type, and
the capacity of each type is found in reference 4. Solving,
N = 14,883
So the LTO's per year by type for U.S. carrier international flights
are:
3 engine super stretch: 1637 LTOs/year
3 engine jumbo: 4613 (5)
4 engine jumbo: 8632
-------
-8-
Foreign Carriers -
Again some estimate of .the'LTD distribution of types is required
for 1990. For a lack of a better resolution, it is arbitrarily taken
that the foreign carrier LTOs are distributed by type according to the
ratios of types found in a future U.S. fleet, appropriately adapted.
This implies two pertinent thoughts: (1) the future foreign carrier
fleet largely parallels the future U.S. fleet, at least for international
(long range) activity; (2) for overseas travel, the flight times are
comparable for all types (there being no short haul) and so it may be
expected that the ratio of LTOs to number of type is the same for all
the types used on international flights.
Two adaptations are made, however. First, it is arbitrarily
assumed that 10% of the foreign fleet is still flying 4 engine narrow
body types in 1990. This is to reflect the trend that many smaller
foreign airlines have neither the need for nor the capital to purchase
the large, but expensive jumbos. Second, it is postulated that the
foreign fleets will not use the B7X7 for international travel, but will
rely upon the 2 engine jumbo, an original European aircraft, to fill
that slot. Thus, using the U.S. carrier fleet projection from reference
7 and incorporating the above adaptations, it is found that the distribution
of foreign carrier LTOs at JFK in 1990 are:
4 engine jumbo - 20%
3 engine jumbo - 33%
2 engine jumbo - 37%
4 engine narrowbody- 10%
100.0%
From this distribution and the passenger requirement (3), the total LTOs per
year(N) is given by
Nx(0.20x400x.7 + 0.33x380x0.7 + 0.37x350x0.7
+ 0.10x190x0.7) = 4,160,000
The 2 engine jumbo seating is given in reference 4, and again the load
factor is 0.7. Solving for N gives
N = 16,790
Therefore, by types, the foreign carrier LTOs/year are:
4 engine narrow body: 1679 LTOs/year
2 engine jumbo: 6212
3 engine jumbo: 5541 (6)
4 engine jumbo: 3358
Finally there are the U.S. domestic passenger who require aircraft.
Reference 3 and statement (1) above give the total for JFK of
-------
-9-
Domestic PAX ('74) = 4,469,000
Domestic PAX ('90) = 12,995,000 .
which is a growth factor of 2.9 times the 1974 figure over the 16 year
period. It is assumed that this growth factor applies also to the
individual categories of domestic:travel (short, medium, and long haul)
whose 1974 passenger levels are given in.reference 3. While undoubtedly
not true to some degree, it is the.most conservative assumption to make
lacking a realistic estimate of the individual growth rate of each
distance category.
Then, as certain aircraft types are associated with specific cate-
gories of usage (eg, 2 engine narrow body types for short haul), the '
LTOs required of each aircraft type to serve the passengers of each
category are readily computed as follows:
Category
Type
'74 PAX (x2.9) '90 PAX
Aircraft LTOs
Capacity required
short
haul
medium haul
2
3
3-
eng
eng
eng
narrow
narrow.
super str
49 7K
1407K .
-
1445K
1606K.
2486K.
115
150
190
17
15
18
,957
,.294*'
,693*^
long haul 4 eng narrow
3 erig jumbo
4 eng jumbo
1168K
783K
614K
- -
7459K 380 28,041***
* at 70% load factor
** Ratio of LTOs based upon project fleet ratio of these types at the time
in question. Fleet projection is discussed on pp. 16.
***This scenario is consistent with the assumptions listed on p. .§,
This concludes step 4.
Part I may then be summarized:
-------
-10-
Table U
Total JFK LTD cycle frequency (per year) in 1990
Type
U.S. PAX
Domestic
U.S. PAX Foreign
International PAX
U,S.
Freight
2 engine
narrow 17,957
3 engine
narrow 15,294
4 engine
narrow
3 engine
super str. 18,693
2 engine
jumbo
3 engine
jumbo 28,041
4 engine
j umbo
Concorde
AST
1,637
4,613
8,632
6,505
2,285
6,212
5,541
3,358
7,000
2,460
7,124
Total
17,957
15,294
1,697
20,330
6,212
38,195
19,114
13,505
4,745
137,031
II. Aircraft Emissions in FY 1990.
This part consists of two phases, the first being the specification
of the LTO emissions by aircraft type and standard involved and the
second being the prediction of the fleet distribution by type and
standard met.
Specification of the LTO Emissions
In order to compare the effect of the standards on the aircraft
emissions in general it is necessary to assume on one hand that in 1990
the standards do not exist (save for the present JT8D in-use smoke
standard which is already in force), and on the other, that the present
standards are being enforced in 1990. Therefore, it is necessary for
each type to specify emissions performance for no standards, newly
manufactured engine standards, newly certified engine standards, and the
special JT3D in-use smoke standard.
The EPA standards are predicated upon an LTO cycle which has 26
minutes of taxi/idle time total for inbound to and outbound from the
terminal. If the emissions performance of an engine is known in terms
of the EPA regulatory parameter (EPAP) or if it is presumed (ie, to meet
a particular standard), then the pounds of pollutant over that cycle can
be found by
-------
-11-
Pounds of pollutant = EPAP x (Impulse/1000).
where the impulse is that over .the entire cycle in pounds-thrust x
hours.
However, at JFK the typical LTO cycle (at least in 1976) has a 29
minute taxi/idle duration (reference 8). This has a significant effect
on the hydrocarbon (HC) and carbon monoxide output as both are produced
nearly exclusively in that mode, but a much more diluted effect (5-15%)
on the oxides of nitrogen (NOx) output as that produced largely in the
high power modes. For those engines for which the EPA has modal data
(ie, pounds of pollutant per hour per mode), the extra three minutes of
idle in the JFK LTO cycle can be handled directly, but for those engines
for which only EPAP data are available, the effect of the extra idle
must be estimated by reliance upon the modal patterns of similar engines.
Table III below shows all the relevant engines, and their JFK LTO
cycle emissions (ie, 29 minutes of taxi/idle) in their present production
form (i.e., with no standards imposed except for the JT8D infuse smoke
standard). The emissions per LTO cycle at JFK for nonregulated engines
can now be tabulated (Table IV).
It is next necessary to consider the emissions performance of
engines that comply with"the standards for newly manufactured' engines
(NME). Actual emissions performances'cannot be predicted so it is
necessary to assume only that each engine will just meet the standards
with no margin. This is conservative as the standards require all
engines of a kind to comply which implies with the statistical variation
involved in the testing procedure that the average emissions of a type
of engine must surpass the standards by a healthy margin.
For all engines except the JT3D and the Olympus 593, the emissions
levels are estimated as follows:
Ibs of HC or CO (JFK LTO) =
EPAPHC>CO std x (Impulse/1000) x (29/26)
Ibs of NOx (JFK LTO) = (7)
EPAPNOx gtd x (Impulse/1000) x [0.15x(29/26) + 0.85]
and the relevant standards are:
EPAP Std
HC 0.8
CO 4.3
NOx 3.0
-------
-12-
Table III
No Standards Emissions
Pollutant (Ibs/LTO cycle - JFK)
Engine
CF6-50C
CFM56
CF6-6D
JT10D
JT9D-70
JT9D-7
JT8D-17*
JT8D-15*-!-
JT3D-7*
JT3D-7
RB211-22B-H-
RB211-524++
Olympus 593
AST engine
HC
18.4
1.5
11.3
9.6
27.0
7.2
5.9
33.5
60.0
57.5
41.1
53.0
68.8
CO
46.4
19.0
33.3
assumed same as
39.6
71.8
26.1
24.1
47.4
72.0
82.4
57.7
199.7
259.4
NOx
29.8
6.8
21.9
CFM56
28.8
22.6
12.2
10.5
9.6
6.4
27.6
39.8
26.7
34.7
Reference
9
10
11
12
12,
13,
11,
11,
11,
17
17
18
**
13
14
15, 16
15
15
* Smokeless type combustor (already in use on the JT8D, but not on
the- JT3D) ..
+ Distribution of pollutants in each mode assumed to be the same
as for the JT8D-17 from reference 16.
++ For the -22B, the following corrections to the EPAP value were used
based upon the known modal distribution of the CF6-6D: For HC, CO:
Ibs of pollutant = (Ibs of pollutant)..,-.- TTn x if 0.9 x
(29/26) + 0.1}
For NOx:
Ibs of NOx = (Ibs of NOx)EpAp LTQ x {0.1 x! (29/26) "+ 0.9}
For the -524, the corrections were based upon the known modal
distribution of the CF6-50C:
Ibs of HC = (Ibs of HC)EpAp LTQ x (29/26)
Ibs of CO = (Ibs of CO)EpAp LTQ x {0.95 x (29/26) .+ 0.05}
Ibs of NOx = (Ibs of NOx).- Trpn x {0.05 x (29/26) + 0.95}
LIU
** Engine not in existence. Estimated by assuming a 50K Ib thrust
engine and ratioing the Olympus 593 values by the the AST engine/
Olympus 593 thrust ratio (50K Ibs /38.5K Ib)
-------
-13-
Table IV
Non-regulated Emissions
Ibs/LTO/engine
Aircraft Characteristic
Type Engine HC CO NOx
2 engine narrow JT8D-15 5.9 24.1 10.5
3 engine narrow JT8D-15 5.9 24.1 10.5
4 engine narrow JT3D-7 (smokey) 60.0 72.0 6.4
3 engine super str. CFM56, JT10D 1.5 19.0 6.8
2 engine jumbo CF6-50C 18.4 46.4 29.8
3 engine jumbo *** 29.1 54.0 26.4
4 engine jumbo JT9D-7 27.0 71.8 22.6
Concorde Olympus 593 53.0 199.7 26.7
AST AST engine 68.8 259.4 34.7
*** assumes an equal mix of DC-10-10s (CF6-6), DC-10-30s (CF6-50),
and LlOlls (RB211-22B)
The first equation presumes that all the HC and CO comes from the idle
mode, which is essentially true for the low emissions combustors that
would be used to comply with the standards. The second "equation is
based upon an estimate that 15% of the LTO NOx comes from the idle mode.
On the average, this appears to be true for the low emissions combustors
explored so far (a high of 25%" at idle for JT8D-17'and'a'low of 10% for-
the CF6-6D, for instance).
The JT3D will not meet the NME standards but will be forced to
comply with an in-use engine smoke standard. The data are supplied in
Table II.
The Olympus 593 performance is based on reference 18. The AST, if
it is to meet any standard, will meet the NCE standards and so is not
included in Table V below. For aircraft haying engines which comply with
the newly manufactured engine standards, the emissions performance over
the JFK LTO cycle is shown in Table VI.
Finally, the emissions levels of engines complying with the newly
certified engine (NCE) standards must be addressed. As with the NME
standards emissions discussed above, it can only be assumed that each
engine will just barely comply with the requisite levels; it cannot be
assumed that any one will exceed the standards. Furthermore, in this
case, only new types of engines are to be considered. Hence, no existing
engine types are referenced. For each category of aircraft an appropriate
sized engine is selected and LTO (EPA) impulse computed assuming a 5%
idle. The emissions are then computed using equation (7). with the EPAP
standard values for newly certified engines (NCE) of,
-------
-14-
Table V
Newly Manufactured Engine Standards Emissions Pollutant
(Ibs/LTO cycle-JFK)
Engine Impulse* HC .CO NOx
JT3D-7**
JT8D-17
JT9D-7
JT9D-70
JT10D
CF6-6D
RB211-22B
RB211-524
Olympus 593
1584
1456
4546
4666
3007
3731
4442
3002
.5
1.3
4.1
4.2
(assumed same as
2.7
3.3
4.0
12.6
47.4
7.0
21.8
22.4
CFM56)
14.4
17.9
21.3
96.0
9.6
4.4
13.9
14.2
9.2
11.4
13.6
26.7
* Pounds-thrust x hours over the EPA LTD cycle (26 minutes taxi/idle).
EPA LTD cycle available from reference 19, rated thrust information
available from reference 4, and engine idle point definitions available
in references 9-18.
** Complies with in-use smoke standard, not NME standards.
Table VI
Newly Manufactured Engine Standards Emissions
Ibs/LTO/engine
Type . Engine HC JX) NOx
2 engine narrow
3 engine narrow
4 engine narrow*
3 engine super str.
2 engine jumbo
3 engine jumbo
4 engine jumbo
Concorde
JT8D-17
JT8D-17
JT3D-7
CFM56 (JT10D)
CF6-50C
**
JT9D-70
Olympus 593
1.3
1.3
33.5
1.6
3.5
3.4
4.2
12.6
7.0
7.0
47.4
8.5
18.6
18.1
22.4
96.0
4.4
4.4
9.6
5.4
11.8
11.5
14.2
26.7
* Complies only with in-use smoke standard, not NME standards
** Equal mix of DC-10-10 CCF6-6D), DC-10-30 (CF6-50C), and L1011
(RB211-524).
-------
-15-
EPAP Std
HC . 0.4
CO. 3.0
NOx 3.0
The engines are:
A. Jumbo aircraft: 50,000 pound-thrust engine, idle - 5%, impulse
(EPA T2 LTO cycle) = 4225 pound-thrust x hours.
B. 3 engine super stretch and 2-3 engine narrow body: 22,000 pound-
thrust engine, idle = 5%, impulse = 1859 pound-thrust x hours.
C. AST: 50,000 pound-thrust engine, idle - 5%, impulse (EPA T5 LTO
cycle) = 3899 pound-thrust x hours.
Thus, the engine emissions over the JFK LTO cycle are:
Ibs/LTO cycle (JFK)
Engine Impulse HC . CO NOx
A
R .
C*
.-> 4225
1859
3899
1.9
0.8
4.1
14.1
6.2.
32.8
12.8
5.6
17.8
* Modal contribution is determined by Tables X and XII of reference 20,
scaled to 50K Ib thrust, not by equation (7).
The emissions per LTO cycle at JFK for NCE regulated engines are then:
Table VII
Newly Certified Engine Standards Emissions
Ibs/LTO/engine
Type
Engine
HC
CO
NOx
2 engine narrow
3 engine narrow
3 engine super str.
2 engine jumbo
3 engine jumbo
4 engine jumbo
AST
B
B
B
A
A
A
C
0.8
0.8
0.8
1.9
1.9
1.9
4.1
6.2
6.2
6.2
14.1
14.1
14.1
32.8
5.6
5.6
5.6
12.8
12.8
12.8
17.8
There are no 4 engine narrow body aircraft which would comply with the
NCE standards.
-------
-16-
The second step of this part is the projection of the fleet distribution
of the level of compliance with the emissions standards. This is necessary
in order to ratio the LTOs of each type according to the level of emissions
compliance (ie, no standards, NME or NCE standards compliance). The
basic data come from reference 7 which offers a U.S. fleet projection
through 1985. It is then necessary to extrapolate this projection to
1990 and to assume that a comparable distribution holds for the aircraft
types in the foreign fleet using JFK.
Reference 7 postulates that there is no SST in the U.S. fleet and
is therefore distorted for this purpose. The existence of an SST in the
U.S. fleet would impact the numbers of 3 engine and 4 engine jumbo
aircraft, specifically through a lower production rate in the 1980' s.
From (4), U.S. carriers haul 48% of the SST PAX and it is thus
assumed that the U.S. will possess 48% of the global SST fleet of 110
Concordes and 40 ASTs. Therefore, the U.S. SST fleet carries
Concorde: 120 x .7 x 53 x 2 = 8904 PAX
AST: 250 x .7 x 19 x 2 = 6650 PAX
per day, assuming two departing flights per day.
Subsonic competitor aircraft C3 and 4 engine jumbo) individually carry
per day ,
3 engine jumbo: 380 x .7x1=- 266. PAX . : :.-.-
4 engine jumbo: 400 x .7x1= 280
assuming one departing flight per day. Also assuming, for convenience,
about equal numbers of PAX on the two subsonic types, then
_ 8904 + 6650 _
" .5 x (266 + 280) ~
or about 29 three engine jumbos and 28 four engine jumbos are equivalent
to the U.S. SST fleet of 53 Concordes and 19 ASTs (out of a global SST
fleet of 150). Furthermore, as the Concorde is basically an aircraft
whose engine will be held to the NME standards as far as the U.S.
airline purchases are concerned, it is logical to assume that its subsonic
equivalent fleet would also be subject to the NME standards. Thus, U.S.
Concordes serve
120 x .7 x 53 x 2 = 8,900 PAX/day
(all airports) and the equivalent subsonic fleet would be
o
N = .5x(266 280T = 32
-------
-17-
of which, as postulated above, half are 3 engine jumbo and half are 4
engine jumbo. Treating the AST in the same fashion, it is found that 25
subsonic jumbos are necessary to replace the AST (and vice versa), again
equally split between 3 and 4 engine aircraft. Thus in summary, the
U.S. SST fleet of 53 Concordes (NME) and 19 ASTs (NCE) is equivalent to
Standard 3 engine jumbo 4 engine jumbo
NME 16 16
NCE "13. 12
29 28
Reference 7 records only the net aircraft of each type (2 engine
narrow, etc.) in the fleet each year up to 1985. Three additional pieces
of information must be added by hypothesis or assumption:
1. Attrition - With or without continued production, older planes
(those complying with no standards) are removed from service. Attrition
is estimated here by postulating a 20 year life (initial production
dates given in reference 5), and guessing at the initial production
rate on the basis of the fleet size after five or more years (as given
by reference 7). The attrition rate after the first twenty years of
service is then roughly equal to that initial production fate.
2. Extrapolation - As reference 7 goes only up until 1985, the
projection is extrapolated to 1990 by continuing the net growth rate of
the 1983-1985 period through 1990".; The production rate is- thus deter-. -
mined by the net growth and the attrition. While there is no sound
reason for this simple extrapolation, any other projection is equally
arbitrary within the available knowledge and also suffers from a lack of
a historical basis.
3. Production of NCE aircraft - The T2 class NCE standards go into
effect in 1981, but it cannot be expected that after that date all newly
produced aircraft will be powered by engines subject to those standards
(Recall that the NCE standards apply only to engines that are newly
certified; continued production of existing engine types must comply
only with the NME standards). It is assumed here that the first NCE
type engines will be produced during 1984 and will constitute 20% of the
production. Each succeeding year will add another 20% until 1989,
during which and thereafter, all engines built will meet the NCE standards.
Tables VIII through XII summarize the information of reference 7
as extended and amended according to the above mentioned criteria.
As no projections are available for the foreign fleet using JFK, it
is necessary to assume, as discussed above, that each type in that fleet
will have a distribution of levels of emissions compliance the same as
the U.S. fleet. The presence of the 2 engine jumbo in the foreign fleet
-------
Table VIII
Type: 2 engine narrow body
Year 1979 1980 1981
1982
1983
1984
1985
1986
1987
1988
1989
'* As of January 1
standard body aircraft began production in 1964; estimated initial production rate -20/year
H~
stretched body aircraft began production in 1967; estimated initial production rate-=60/year
Net growth rate (1983 - 1985) =0.5%
1990
Production
(No std)
(NME)
(NCE)
Attrition
(No std)
Net in*
Fleet
(No std)
(NME)
(NCE)
0
37
0
0
684
0
0
0
32
0
4
684
37
0
0
19
0
5
680
90
0
0
14
0
4
675
88
0
0
5
0
7
671..
102
0
, 0 0
11 10
3 6
20+ 20
;' 664 644
'-... 107 118
0 3
0
6
10
20
624
128
9
0
15
61
80++
604
134
19
0
0
76
80
524
149
80
0
0
76
80
444
149
156
364
149
236
00
I
-------
Table IX
Type: 3 engine narrow body
Year 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990
Production
(No std) !
(NME) 00000000
(NCE)
Attrition
(No std) 5 22+ 63 48 23 20 32 32
Net in* !.
Fleet
(No std) 840 835 813 750 702 679 659 627
(NME). 0 0 0 00 0 0 0
(NCE) 000 0 0 0 00
000
32 92++ 92
595 563 471 379
0000
0 0 0 0
* As of January 1
standard body aircraft began production in 1961; average estimated production rate -32/year
(these attrition figures to 1985 based on reference 7 directly).
i i
stretched body aircraft began production in 1968; estimated initial production rate =60/year.
-------
Type: 3 engine super stretched body
Year 1979 1980 1981 1982
Table X
1983 1984
1985
1986
1987
1988
* As of January 1
+ Production starts 1978
Net growth rate (1983 - 1985) = +15.3%
1989
1990
Production
(No std)
(NME)
(NCE)
Attrition
(No std)
Net in*
Fleet
(No std)
(NME)
(NCE)
0 . .
51
0
0 00
77+ 77
0 51
0 0
0 '' 0
78 54
0 14
000
. 77
. ; 379
. 0
0
33
22
0
77
433
14
0
36
53
0
77
466
36
0
20
82
0
77
502
89
0
0
118
0
77
522
171
0
0
136
0
77
522
289
0
77
522
425
O
I
-------
Table XI
Type: 3 engine jumbo body
Year 1979 1980
1981
1982
1983
1984
1985
1986
1987
1988
* As of January 1
Production started in 1969; estimated initial production rate =30/year
Net growth rate (1983 - 1985) = +9.3%
1989
1990
Production
(No std) 0 ...
(NME) 22
(NCE) 0
Attrition
(No std) 0 '0 0 0
Net in*
Fleet
(No std) 305- 305
(NME) 0 22
(NCE) 0 0
i
00 0 0 0
40 34 28 20 11
08 19 31 45
00000
305 305 305 305
. 157 191 219 239
';
: 0 8 27 58
0 0
0 0
61 97
0 30+
305 305
250 250
103 164
275^
(275)
250
(234)
261
(248)
I
N>
SST adjustment in parentheses. NME and NCE production has been reduced by 1990 by 16 and 13 aircraft
respectively to account for the SST aircraft in the U.S. fleet.
-------
Type: 4 engine jumbo body
Year 1979 1980
Table: XII
. I. .;
1981
1982
1983
1984
1985
1986
1987
1988
* As of January 1
Production began in 1968; estimated initial production rate =20/year
Net growth rate (1983 - 1985) = 11.9%
1989
1990
Production
(No std) 0
(NME) 17
(NCE) 10
Attrition
(No std) 0 0 0
Net in*
Fleet
(No std) 164 164
(NME) 0 17 .
(NCE) 0 0 . .
0 .' 0 0 0 0
29 26 22 16 9
.-0 .6 14 24 36
0 0 0 0 00
164 164 164 164
107 133 155 171
0 6 20 44
0
0
70
20+
164
180
80
0
0
76
20
i
144 124 .£
(124)"
180 180
(166)
150 226
(214)
SST adjustment in parentheses. NME and NCE production has been reduced by 1990 by 16 and 12 aircraft
respectively to account for the SST aircraft in the U.S. fleet.
-------
-23-
requires the additional assumption that its distribution of levels of
compliance is the same as that of the 3 engine jumbo in the U.S. fleet,
an aircraft of similar age and generally similar use.
If the LTD cycle frequency at JFK of the different aircraft types
reflects the distribution of levels of emissions compliance as presented
in Tables VIII through XII then, the LTO cycle frequency for 1990 at JFK
(Table II) can be broken down as follows:
Table XIII
LTO cycles per year (JFK)
Type
2 engine narrow
3 engine narrow
4 engine narrow
3 engine superstr.
2 engine jumbo*
3 engine jumbo
4 engine jumbo
SST**
No Standards
8,727
15,294
1,679
1,528
2,173
13,363
4,472
4,867
NME Standards
3,572
10,364
1,976
12,149
6,492
8,517
NCE Standards
5,658
8,438
2,063
12,683
8,150
4,866
.-+-- Foreign carriers only. Production-assumed" ceased prior to 1979.
* Foreign carriers only. See comment in text regarding assumed dis-
tribution.
-H- U.S. carriers only.
** Global distribution postulated based on anticipated production rates
and possible entry date of an AST.
III. Impact Calculation
The annual pollution contribution of each type of aircraft is calcu-
lated according to the formula:
3
Pollutant/year/type = £ (Number of LTOs/type/year) x
1=1
(Number of engines per aircraft for given type) x
(pollutant/engine over JFK LTO cycle for given type);
for each of the three pollutants, HC, CO, and NOx. The summation over
i (1, 2, 3) is for the independent consideration of each of the three
levels of compliance, No Standards, NME Standards, and NCE Standards.
The distinction of the level of compliance affects two terms, (1) the
number of LTO cycles per year per type (Table XIII), and (2) the pollution
level per engine over the cycle (Tables IV, VI, and VII).
-------
-24-
Two Opposite Cases are Treated:
CD No Standards. This estimates the aircraft pollution load in
1990 if all standards not presently enforced (e.g., the JT8D smoke
standard is presently enforced) are revoked. This then forms a baseline
against which to compare the utility of the standards if enforced as
presently promulgated (or about to be, in the case of the T5 class).
(2) Standards implemented as presently promulgated, including the
draft T5 class standards. This represents the optimum situation (maximum
control). Further improvements in the emissions by aircraft at JFK in
1990 must come from one or more of four possible choices: (a) promulga-
tion of standards for in-use engines for either or both of the T2 and T5
classes (retrofit), (b) improvements in the time in the taxi/idle mode
at JFK in the future, (c) more rapid replacement of old aircraft with
new, principally those meeting the NCE standards, and (d) a different
distribution of aircraft types. The EPA has control over (a), the FAA
might be able to achieve improvements through (b) and (c)_, the latter
indirectly through noise control regulations, while improvements through
method (d) would arise largely through market forces.
Consider first the case of no standards at all (except for the T4
class or JT8D in-use engine smoke standard now in force, which achieves
large reductions in HC and CO). The results are presented in Table XIV.
Table-XIV
JFK 1990 Emissions with No Emissions Standards
in Effect
Type
2 eng
3 eng
4 eng
3 eng
nr
nr
nr
nr
LTOs/
year
17,957
15,294
1,679
20,330
No. of
engines
X
X
X
X
2
3
4
3
Pollutants/LTO/engine
HC CO NOx
X
X
X
X
(5.9,
(5.9,
(60.0,
(1.5,
24.1,
24.1,
72.0,
19.0,
10.5)
10.5)
6.4)
6.8)
Tons of pollutant/year
HC CO NOx
106
135
201
46
433
553
242
579
189
241
21
207
superstr
2 eng
3 eng
4 eng
J
J
J
6,212
38,195
19,114
X
X
X
2
3
4
X
X
X
(18.4,
(29.1,
(27.0,
subsonic
46.4,
54.0,
71.8,
subtotal
29.8)
26.4)
22.6)
114
1,667
1,032
3,301
288
3,094
2,745
7,934
185
1,513
864
3,220
Concorde 13,505 x 4
AST 4,745 x 4
x (53.0, 199.7, 26.7)
x (.68.8, 259.4, 34.7)
supersonic subtotal.
grand total
1,432 5,394 721
653 2,462 329
2,085 7,856 1,050
5,386 15,790 4,270
-------
-25-
Consider next the case in which all the presently promulgated stan-
dards and the about to be promulgated T5 class standards are implemented.
The results are presented in Table XV. The figures of Tables XIV and XV
or manipulations of these numbers appear in Table I of the preamble to
the draft T5 class (SST) emissions regulations, appropriately rounded
off.
-------
Table XV
JFK 1990 Emissions with Standards
in Effect
Level of
Type Compliance*
2 eng narrow
3 eng narrow
4 eng narrow
2 eng Jumbo
3 eng Jumbo
4 eng Jumbo
3 eng
superstr
NS
NME
NCE
NS
**
NS
NME
NCE
NS
NME
NCE
NS
NME
NCE
NS
NME
NCE
LTOs/
Year
8,727
3,572
5,658
15,294
1,679
2,173
1,976
2,063
13,363
12,149
12,683
4,472
6,492
8,150
1,528
10,364
8,438
No. of
Engines
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
2
2
2
3
4
2
2
2
3
4
3
4
4
4
3
3
3
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Pollutants/LTO/cycle
HC CO NOx
(5.9,
(1.3,
(0.8,
(5.9,
(33.5,
(18.4,
(3.5,
(1.9,
(29.1,
(3.2,
(1.9,
(27.0,
(4.1,
(1.9,
(1.5,
(1.6,
(0.8,
24.1,
7.0,
6.2,
24.1,
47.4,
46.4,
18.6,
14.1,
54.0,
17.0,
14.1,
71.8,
22.0,
14.1,
19.0,
8.5,
6.2,
10.5)
4.4)
5.6)
10.5)
9.6)
29.8)
11.8)
12.8)
26.4)
10.8)
12.8)
22.6)
14.0)
12.8)
6.8)
5.4)
5.6)
subsonic subtotal
Concorde
AST
NS
NME
NCE
4,867
8,517
4,866
X
X
X
4
4
4
X
X
X
(53.0,
(12.6,
( 4.1,
supersonic
* NS = No Sta
inrlardR
gra
ind total
199.7,
96.0,
32.8,
subtotal
26.7)
26.7)
17.8)
Tons of Pollutant/year
HC CO NOx
51.5
4.6
4.5
135.4
112.5
40.0
6.9
3.9
583.3
58.3
36.2
241.5
53.2
31.0
3.4
24.9
10.1
1,401.2
515.9
214.5
39.9
770.4
2,171.6
21.03
25.0
35.1
552.9
159.2
100.8
36.8
29.1
1,082.4
309.8
268.5
642.2
285.7
229.8
43.6
132.1
78.5
4,221.8
1,943.9
1,635.3
319.2
3,898.4
8,120.2
91.6
15.7
31.7
240.9
32.2
64.8
23.3
26.4
529.2
196.8
243.5
202.1
181.8
208.6
15.6
84.0
70.9
2,259.1
259.9
454.8
173.2
887.9
3,147.0
NME = Newly Manufactured Engine standards
NCE = Newly Certified Engine standards ;
** Complies only with the T3 class (JT3D) in-use engine smoke standard
which produces substantial gains in HC and CO control.
i
ISJ
-------
-27-
References
1. DOT/FAA, Terminal Area Forecast, September 1974.
2. DOT/FM, 1973 Airport Activities. Statistics, (year ending 12-31-73)
3. DOT/FAA, 1974 Airport Activities Statistics, (year ending 12-31-74)
4. Aviation Week, Inventory Issue, March 15, 1976, p. 133.
5. Jane's, All the.World's Aircraft, 1972-73.
6. NASA, Advanced Supersonic Propulsion Study, Final Report, NASA
CR-134633, January 1974.
7. Communication with Mr. Hannan, FAA, Aviation Forecast Branch,
based on FAA, Aviation Forecasts Fiscal Years, 1973-84.
8. Port of New York Authority, A Study of Airline Departure Delays
at Kennedy International Airport, November 1964.
9. General Electric letter to EPA, September 24, 1975.
10. General Electric communication to EPA, July 29, 1975.
11. General Electric letter to EPA, September 29, 1975.
12. Pratt and Whitney letter to EPA, July 25, 1975.
13. NASA, Status.of Technological Advancements for Reducing Aircraft
Gas Turbine Engine Pollutant Emissions, NASA TMX-71846, December,
1975.
14. Pratt-and Whitney letter.to EPA, March 30, 1976.
15. Pratt and Whitney letter to EPA, December 17, 1974.
16. Cornell Aeronautical Laboratory Report, Analysis of Aircraft
Exhaust Emission Measurements; Statistics. CAL No. NA-5007-K-2,
November 19, 1971.
17. Rolls Royce submission to the Aircraft Hearings, January 28, 1976.
18. Rolls Royce submission in response to the T5 class NPRM of
July 24, 1974.
19. EPA, Control of Air Pollution from Aircraft and Aircraft Engines,
FR, vol. 38, No. 136, July 17, 1973.
20. EPA Technical Support Report, Alternative Derivative of the
Standards for T5 (Supersonic Transport) Class Gas Turbine Aircraft
Engines, EPA AC-76-01, January 1976.
------- |