AC78-01
Technical Support Report for Regulatory Action
Cost-Effectiveness Analysis of the Proposed Revisions
in the Exhaust Emission Standards for
New and In-Use Gas Turbine Aircraft Engines
Based on EPA's Independent Estimates
by
Richard S. Wilcox
Richard W. Hunt
February 1978
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 informa-
tion 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
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TABLE OF CONTENTS
Introduction 1
Methodology 2
Discussion 6
Part 1 6
Part II 30
Conclusions 39
References 40
Appendix A Derivation of Emissions Reduction
and Fuel Savings—Additional Infomation A-l
Appendix B Fleet Projection and Engine Inventory B-l
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INTRODUCTION
To determine the most efficient means of achieving the National
Ambient Air Quality Standards (42 CFR §420), the cost effectiveness of
various pollution abatement control strategies are compared and the most
effective are implemented. This report contains a cost-effectiveness
analysis of the proposed revisions in exhaust emission standards for new
and in-use aircraft gas turbine engines using EPA's independent cost
estimate.
The control strategies analyzed are:
1. Control of newly manufactured gas turbine engines in 1981
for HC and CO only;
2. Retrofit of in-use gas turbine engines in 1985 for HC and CO
only (to the same levels as in #1); and
3. Control of newly manufactured gas turbine engines in 1984 for
HC, CO, and NOx.
Discrepancies between industry estimates and data from earlier EPA
studies (References 1 and 2) made it necessary for the EPA to prepare an
independant cost estimate.
This interim report represents EPA's preliminary cost analysis in
a continuing effort to expand and update its cost information in a
timely manner. Care must be taken in interpreting the results of this
analysis. Because of the complexity of the subject matter and the
uncertainties which prevail, the choice of simplifying assumptions can
have a significant effect on the direction of the results. Every effort
has been made to present a realistic scenario of the costs of control.
The subsequent final report will be more precise and will incorporate
information received during the comment period of the Notice of Proposed
Rule Making concerning this regulatory action.
The Discussion section of this analysis is divided into two main
portions. Part I was prepared to allow a direct comparison with gas
turbine engine manufacturers' estimates as published in TSR AC77-02
(Reference 3), although the cost-effectiveness figures are not directly
comparable since this report includes the latest FAA fleet projection
(Reference 4) and other modifications. Part II presents an alternative
way to compute the cost-effectiveness of the proposed standards. This
alternative reflects the uncertainty associated with the promulgation of
a NOx standard in 1984. It differs from Part I in that the 1981 NME
Standard is projected as the final requirement for all newly manufactured
engines. The second part also differs from the first in the method of
determining the incremental burden associated with the possibility of
NOx control.
In addition, the purpose of this analysis is to present EPA's cost
estimates; therefore, the discussion of several important elements
presented in TSR AC77-02 is not repeated in detail here.
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METHODOLOGY
The procedure used in this analysis consisted of determining the
cost increment and the total reduction in fleet exhaust emissions for
each control strategy. A portion of the total cost was then applied to
each individual pollutant. The resulting HC, CO, and NOx cost-effectiveness
factors are defined in terms of dollars spent per ton of pollutant
reduced ($/ton). The undiscounted lifetime costs (zero discount rate),
expressed in 1976 dollars, are used throughout this analysis.
As previously mentioned, several elements which were detailed in
the previous cost-effectiveness report are not repeated in this study.
Some of these elements are a part of the methodology and include:
1. The derivation of emissions reduction over an engine's lifetime;
and
2. The derivation of fuel savings associated with the proposed
standards.
For a detailed discussion of these derivations the reader should refer
to TSR AC77-02 (Reference 3).
This analysis includes several engine families which were not part
of TSR AC77-02. Recent information indicates that the JT8D-209, CF6-32,
and RB211-535 may hold significant shares of the market in compliance
with the standards under consideration. The EPA has very little data on
the JT8D-2G9,-and no data on. the, CF6-32 and RB211-535. (The latter
engines are clipped fan versions of the CF6-6 and RB211-22B, and are
presumed to be in the design phase, therefore, very little information
is available.) The assumptions used to derive the statistics necessary
to complete the analysis are given in Appendix A. These engines are
further discussed in Appendix B, "Fleet Projection and Engine Inventory".
A brief discussion of each part of the methodology used in this
analysis is presented in the following sections.
EMISSIONS REDUCTION
The pollution abatement brought about by the use of a low-emission
version of an engine is computed by finding the net reduction per
landing-takeoff (LTO) cycle and multiplying that figure by an estimate
of the total LTO cycles the engine will experience during its useful
life.
The number of LTO cycles for each engine are the same as those used
in Reference 3, except that those for the B707 and DC-8 retrofit (JT8D
and CFM56 engines) have been changed to reflect the long-haul low-LTO-
cycle operation of these aircraft (Reference 4, See Appendix A).
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Th'e following1 formulae are used to- determine the'number of LTO--cycles
for specific engines based on their representative aircraft"type. The
inputs come from published CAB data'as found in Reference 3 and 4.
' LTOs/day Daily aircraft utilization in hours (1)
Revenue hours/Revenue departures '
or
' LTOs/day Daily block hours per aircraft (2)
Stage length/Block speed
COST
•The incremental cost of each control strategy is conveniently
separated into four major components: non-recurring, manufacturing,
operating, and maintenance. In most instances, the amounts of each cost
• component were-derived from References 1, 2, 7, 8, and 9. Where costs
were incomplete, vague, or incorrect based on more recent knowledge,'
systematic application of judgment was used to complete the estimate.
Non-recurring. This major component is composed of several' elements:
development, certification, service evaluation,'-initial production,'-"and
engine dedication.- These funds represent" the corporate investment' '
associated? with >the application1 of* demonstratetf technology' ttr specif ic
engine .families and'must be "recovered in the engine selling price.' Not
?T, included are the research'and development (R&D) costs of initial design
,and engine demonstration which were funded through1 U.S. Government
contract and Independent Research and Development (IR&D) money.'" J
Manufacturing. The cost of manufacturing refers only to the
increment, in engine selling price as a1 consequence of the increased
complexity or more expensive materials found in 'a low-emission engine.
This burden is generally attributed to the combustor and fuel supply
system, but may include increased costs to manufacture the' pressure-'
casing and equipment bay.
Operating. In,this analysis, the-operating cost is defined "as the
.increment, injfuel,consumption between regulated and non-regulated
engines. --jNoj performance, penalties (such'as a loss' of thrust) ' ate' expected
from the use of low-emission technology.
.Maintenance.i^Although' generally>considered an!operating expense,
,,maintenance cost is_, segregated • in> this study'Because it'includes'subject
. areas ,for,,which:>no estimates are available,-'or-elements which dre too
abstracj: to<,define. with any certainty.- -These -)expenses'r,'(/typicallyiincurred
by the air carriers, are excluded from this analysis.
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FLEET PROJECTION
Having obtained the emissions reduction and cost of control for
each engine model, it is necessary to average them over the fleet in
order to obtain overall figures. Three fleets are of interest: (1) the
fleet of pre-1981 aircraft which is subject to the 1985 Retrofit Standard,
(2) the 1981 to 1984 aircraft fleet which is subject to the 1981 NME
Standard; and (3) the 1984 and beyond fleet of new aircraft which is
subject to the 1984 NME Standard.
The projection used to obtain each fleet mix (Reference 5) is based
on the FAA's latest fleet projection (Reference 6) and is discussed in
Appendix B.
COST APPORTIONMENT
The costing methodology employed in this analysis is consistent
with that used for automobile emission control strategies (Reference 10).
For the 1981 NME and 1985 Retrofit Standards which control only HC and
CO, no quantitative approach to cost application exists since the same
technology controls both species. For this reason, the cost of control
is divided equally between the two pollutants.
The 1984 NME Standard regulates NOx in addition to HC and CO.
Since the allowable levels for HC and CO are the same as 1981 NME, the
same cost of control is assigned to these two pollutants for 1984 NME
and any additional burden is attributed to NOx control.
~* ~~
COST EFFECTIVENESS
Part I and II
In both parts of the Discussion section; the cost effectiveness for
each of the proposed standards is calculated by first finding the total
cost as follows:
Total Cost =
Total Total selling Total fuel
non-recurring cost price increment consumption increment (1)
For the 1981 NME and 1985 Retrofit Standards, 50 percent of the
total cost is applied to the total reduction in each pollutant (HC and
CO) which yields the final cost-effectiveness ratio.
Cost effectiveness 50% of equation 1 (2)
for pollutant A Total reduction in pollutant A
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Part I
The 1984 NME Standard cost-effectiveness ratio for HC and CO Is the
same as that found by Equation 2 for the 1981 NME Standard. These
ratios are then used to determine the NOx cost-effectiveness ratio in
the following manner:
HC allocation = (Total reduction in HC for 1984) x (Eq. 2 for HC) (3)
CO allocation = (Total reduction in CO for 1984) x (Eq. 2 for CO) (4)
NOx allocation = Eq. 1 for 1984 NME - (Eq. 3 + Eq. 4) (5)
Cost effectiveness _ Eq. 5 (6)
for NOx ~ Total reduction in NOx
Part II
The 1984 NME Standard cost-effectiveness ratio for HC and CO is the
same as that found by Equation 2 for the 1981 NME Standard.
The total cost of NOx control in 1984 is defined by Eq. 1 where:
1) The non-recurring cost is represented by the non-recurring
expenses^ incurred* as a result of- developing and implementing 1984
control technology;
2) The selling price increment is equal to the difference between
the 1984 NME selling price increment and the 1981 NME selling price
increment, multiplied by the number of engines produced under the
1984 standard; and
3) The fuel consumption increment is the difference between
consumption increments calculated for the 1984 in-service engines
when utilizing either 1984 NME or 1981 NME control hardware.
The cost effectiveness is found by the following equation:
Cost effectiveness Eq . 1 , .
for NOx ~ Total reduction in NOx '
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DISCUSSION
Part I
This portion of the Discussion was prepared to allow a direct
comparison with gas turbine engine manufacturers' estimates as pub-
lished in TSR AC77-02 (Reference 3).
EMISSION REDUCTIONS
The exhaust emission reductions were calculated over the useful
life of each engine family. This interval is somewhat arbitrary and was
selected to approximate the corporate accounting lifetime. Newly
manufactured engines are considered to have a useful life of 15 years.
Based on a 15 year aircraft attrition rate, the fleet projection (Ref-
erence 5) forecasts that all retrofitted engines except the CF6-50,
CFM56, and JT8D-209 will have an average useful life of 8 years remain-
ing. The CF6-50 was introduced on later airplane models and would have
expended less of its useful life; therefore, this engine has 11 of its
original 15 year lifetime remaining. The CFM56 and JT8D-209 would be
retrofitted on older aircraft (e.g., B707) which have an average of 12
years remaining before retirement. For this reason, the useful lives of
these engines are also limited to 12 years.
The date of the 1985 retrofit overlaps the 1984 NME Standard by one
year. This means that the new-engine retrofit of aircraft which might
normally comply with the 1985 standard will be forced to use engines
produced under the more stringent 1984 standard. The fleet projection
(Reference 5) shows that 204 engines (CFM56 and JT8D-209) for the
retrofit of the B707 and DC-8 fleets are involved. This retrofit is
dependent on compliance with FAR Part 36 noise regulations which are
effective in 1985. The airlines will probably retrofit these aircraft
with engines manufactured before 1984 to avoid a mix of engines on their
long-haul narrow-bodied aircraft fleets. However, to remain consistent
with the fleet projection and the standards as proposed, this analysis
accounts for the 204 engines under the 1984 NME Standard as previously
stated.
A useful life of 15 years was used for the 204 engines retrofitted
under the 1984 standard instead of the shorter value employed for other
retrofit engines. A re-examination of the fleet projection showed that
as their numbers dwindled, the utilization of the remaining B707 and DC-
8 aircraft increased so that a longer useful life was more appropriate.
Tables 1, 2, and 3 summarize the lifetime reductions in gaseous
exhaust emissions for each engine family as well as the total reduction
for each fleet affected by the 1981 NME, 1985 Retrofit, and 1984 NME
Standards, respectively.
The JT8D-17 (representative of all JT8D family members except the
dash 209), dominates the total lifetime emission reductions brought
about by the 1985 Retrofit Standard (Table 2). The large number of
these engines account for about 40% of the HC and 50% of the CO reduc-
tion totals.
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Table 1
Reduction in Gaseous Emissions
Resulting from the 1981 NME Standards
Model
JT8D-17
JT8D-209d
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56 :
RB211-22B-
RB211-524
TOTAL
Tons/Engine/Lifetime '
HC CO
70
65
146
72
87
125
42
386
351
204
130
264
242
174
207
205
447
472
In-Service
Engines
549
264
124
124
105
226
262
102
102
1858
Total
Tons/Lifetime (000)
HC CO
38.4
17.2
18.1
8.9
9.1
28.3
11.0
39.4
35.8
206.2
125.2
34.3
32.7
30.0
18.3
46.8
53.7
45.6
48.1
434.7
15 year useful life.
See Reference 3 for derivation.
See Appendix B.
See Appendix A.
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Table 2
Reductions in Gaseous Emissions
Resulting from the 1985 Retrofit Standard
Tons/Engine/Lifetime ' In-Service
Total
Tons/Lifetime (000)
Model
JT8D-17
JT8D-209d
JT9D-7
CF6-6
CF6-506
CFM56d
RB211-22B
TOTAL
HC
38
29
78
46
91
19
206
- —
CO
109
58
141
93
152
92
238
Engines
2947
302
616
399
104
302
399
5069
HC
112.0
8.8
48.1
18.4
9.5
5.7
82.2
284.7
CO
321.2
17.5
86.9
37.1
15.8
27.8
95.0
601.3
Useful life is 8 years except as noted.
See Reference 3 for derivation.
See Appendix B.
12 year useful life.
11 year useful life.
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—9—
Table 3
Reductions in Gaseous Emissions
Resulting from the 1984 NME Standards
Total
Model
JT8D-209d'6
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56d
RB211-22B
RB211-524
CF6-326
RB211-5356
JT10D6
TOTAL
Tons/Engine/Lifetime '
HC CO NOx
65
37
140
53
87
122
42
24
- ..386
338
71
294
57
130
71
220
195
195
225
205
115
447
446
160
341
280
65
37
121
63
87
98
26
15
55
95
71
42
36
In-Service
Engines
468
102
1040
1040
738
1437
468
102
738
1085
933
932
933
10,030
Tons/Lifetime
HC CO
30.4
3.7
145.6
55.1
64.2
175.3
19.7
2.4
284.9
366.7
66.2
274.0
53.2
1541.4
59.4
7.3
228.8
202.8
143.9
323.3
95.9
11.7
329.9
483.9
149.3
317.8
261.2
2615.2
(000)
NOx
30.4
3.7
125.8
65.5
64.2
140.1
12.2
1.5
40.6
103.1
66.2
39.1
33.6
726.0
15 year useful life.
See Reference 3 for derivation.
See Appendix B.
Two different annual LTO cycles used. The higher figure represents the twin-engined
narrow-bodied application and the lower figure the B708 and DC-8 retrofit program.
See Appendix A.
See Appendix A.
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The air quality benefits from controlling the JT8D family in 1984
are significant. As shown in Table 3, the contribution of the JT8D-209
to the emission reduction totals is fairly low. This should not suggest,
however, that the engine will be rather unimportant in the 1984 NME
fleet. The low in-service population of this engine is a function of
the broad assumptions which were necessary to complete the fleet projec-
tion. There are indications that the dash 209 may be heavily utilized
in the two-engine narrow-bodied fleet if the DC9 Super 80 is placed in
production.
In a letter from Pratt and Whitney to the EPA (Reference 11), it is
stated that aircraft such as the Super 80 have a market potential of
1000-2000 units by 1990. More specifically, a letter from McDonnell
Douglas to the EPA (Reference 12) forecasts "a market for several
hundred of the DC-9 Super 80 aircraft and its derivatives." Presumably
these are worldwide production figures, but if a significant proportion
of these aircraft are used by air carriers operating in the U.S., the
dash 209 will be a very significant source of pollutants.
The JT10D was omitted in the 1981 NME and 1985 retrofit fleets
(Tables 1 and 2). The engine's production design has not been finalized
and no companion airframe exists at this time. For these reasons, it is
unlikely that JT10D engines will be produced under the corresponding
standards. A more complete discussion of this engine is contained in
the section on engine costs.
The retrofit projection (Table 2) omits a separate category for the
JT9D-70. The number of these retrofitted engines is expected to be
quite small, so rather than venture a grress, the JT9D—70 is included in
the JT9D-7 estimate. Although the dash 70 produces twice as much HC,
the effect of its inclusion on the total emission reduction is insigni-
ficant.
COST
Background
For a more complete understanding of the EPA cost estimate, brief
descriptions of the changes to the turbine engine hot section which are
necessary for compliance with the exhaust emission standards and the
cost components used in this analysis are presented. For a more rigorous
discussion of the technology, the reader should refer to Reference 13.
Complexity. The requisite control techniques can be placed into
three broad categories of development complexity.
Category 1 - Little or no difficulties encountered in development
of the concept on most engines;
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Category 2 - Only some minor to moderate difficulty anticipated in
the development of the concept for an engine, usually associated
with the combustor durability or performance; development is
straightforward, although some time is required; and
Category 3 - A number of difficulties must be overcome in developing
flightworthy hardware; preservation of other design criteria
requires a compromise with the full potential of the emissions
control device.
Complexity categories 1 and 2 essentially control HC and CO for the
1981 NME and 1985 Retrofit Standards, while category 3 adds NOx control
for compliance with the 1984 NME Standard.
Control Methods
Fuel Sectoring. This method is used to improve the combustion
conditions at idle which results in lower HC and CO emissions. Specifi-
cally, during the idle mode combustion is quite lean with an attendant
low flame temperature; consequently, the combustion efficiency is poor
because of inadequate heat to vaporize the fuel and to stimulate the
CO -> CO. reaction* This problem is resolved by eliminating the fuel
flow entirely to a part of the combustor (usually about half) and injecting
it with the rest of the fuel into the remaining, portion of. the combustor.
This has two^ "beneficial effects: (1) the atomization of .the fuel is
improved and (2) the fuel/air ratio is increased (enriched) so that a
hotter flame exists, improving vaporization of the fuel and enhancing
the CO -> CO- reaction.
Minor combustor redesign. This method may consist of rich
primary or delayed dilution concepts. With the rich primary concept,
reducing primary airflow increases the local fuel/air ratio and hence
the primary zone temperature. At low power, this is beneficial since
the higher temperature enhances the CO -»• CO- conversion when 0~ becomes
available in the secondary and aids in fuel droplet evaporation, thereby
improving the consumption of HC. If the primary zone equivalence ratio
is greater than one, smoke becomes a problem requiring complicated air
flow patterns and dilution zones in the secondary to consume it.
The delayed dilution concept consists of postponing the introduction
of dilution air, producing a longer combustion zone at intermediate
temperatures. This increases the residence time of the reactants, which
allows the CO -*• CO,, conversion to approach equilibrium and for unburnt
hydrocarbons to be consumed. The difficulty lies in adjusting the air
flow in the intermediate zone at all power settings so it is hot enough
for CO consumption, yet cold enough to prevent NOx, and still achieve
flame stability, liner durability, etc.
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Air blast. The pressure differential that exists between the
compressor and the combustor is employed to produce high velocity air
through a venturi system at the combustor inlet. This air is directed
toward the fuel nozzle to help break up the fuel droplets, resulting in
the elimination of locally rich hot spots and an improvement in combustion
efficiency.
The basic concept is relatively simple since it only requires the
addition of venturi tubes. However, to achieve the standards in most
cases, it usually proves necessary to also optimize the airflow distribution
of the liner. For this reason, the concept is placed in the second
category of complexity.
Fuel staging. The combustor is divided into two regions, each
having its own fuel injection system. These are termed the pilot stage
and the main stage. At low power, fuel is supplied only to the pilot
stage, thereby allowing a much higher local fuel/air ratio than would be
possible if the fuel were distributed throughout the combustor. This
mixture is then able to burn hotter, enhancing the CO -»• C0? conversion
and droplet evaporation (reducing HC).
At high power, the fuel is distributed between the two stages in
such a way so as to minimize the peak temperature. This aids in pre-
venting NOx production. Staging requires two fuel injection locations
which adds to the complexity of the fuel supply system and the fuel
control. The combustor liner is also more complex with additional
cooling and temperature profile problems.
Table 4 summarizes the low-emission technology which is necessary
for compliance with the standards.
Cost component elements. In this analysis the components of cost
for each engine family are typically made up of several elements which
when combined, account for all of the expenses incurred by the turbine
engine manufacturers. Where appropriate these elements also include
corporate profit. The main elements within each component are shown in
Table 5.
ENGINE COST ESTIMATES
The cost estimates of the control hardware for each engine family
are based on industry and NASA technology submittals to the Emission
Control Technology Division as of 1 January 1978. A normal development
schedule for the modifications is assumed since no major setbacks are
expected.
Predicated on the information available at this time and with the
knowledge that significant uncertainties exist, the accuracy of the cost
estimates for the 1981 NME and 1985 retrofit technology are considered
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Table 4
Control Complexity
Control Method
1981 NME
and
1985 Retrofit 1984 NME Complexity Category
Sector burning 1
Minor combustor redesign 2
Air blast 2
Fuel staging 3
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Table 5
Cost Components and Their Elements
Component
Elements
Development
Certification
Service Evaluation
Initial Production
Engine Dedication
Non-Recurring Total
New Engine Increment
Retrofit
Design and general laboratory effort
General engine hardware
Specific modification hardware
Various engine tests
General engineering support
Emission testing
Engine hardware
Specific modification hardware
Endurance test
Certification test
Miscellaneous tests
Flight test
Emissions test
General engineering support
Administrative costs
Maintenance
Inspection
Engine hardware
Tool design
Tool procurement
Initial start up
Engines
Development
Certification
Service Evaluation
Initial Production
Engine Dedication
Parts
Labor
Parts
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to be within a factor of 2, while the estimate of the 1984 NME technology
is somewhat less reliable. Therefore, the numbers do not represent
absolute values and should be interpreted with care.
1981 NME and 1985 Retrofit. The cost estimates for controlling HC
and CO are summarized in Table 6. Generally, the differences between
engine families of the same manufacturer are attributed to variations in
modification complexity and engine size.
In all but one case, it is expected that the retrofit will require
new engine parts. However, when production designs become available it
may be found that additional parts can be reworked or modified by airline
maintenance shops at a substanial savings, as is contemplated under the
JT3D smoke retrofit program (Reference 9).
JT10D. This engine is excluded from the 1981 NME analysis
because it is a new engine which has not been certified and does not
have a companion airframe at this time.
There has been some discussion concerning a growth version of the
original engine design being used on the Boeing 7S7 aircraft. However,
the Boeing design has not been finalized and no certification date or
delivery data has appeared in the literature. As the finalization of
design is delayed, the more likely the production JT10D would contain a
staged combustor (category-3) to avoid economic and-logistic problems.
If the EPA receives-evidence «to- dispute-the-above assumption, the JT10D
will be included in the next cost analysis.
(The same basic argument is true for the clipped fan CF6-32 and
RB211-535 which are also candidates for the Boeing 7S7 as stated in
Reference 14.)
JT9D-7. JT9D-70, and JT8D-209. Air blast is the control method
used by these engine families. The JT9D-7 and JT8D-209 are expected to
require modifications to the nozzles, nozzle supports, liner, and dome,
while the JT9D-70 will require the same changes with the exception of
the dome.
The development cost for the JT9D-7 is greater than the JT9D-70,
reflecting combustor and carburetor modifications which are more significant
departures from production hardware (Table 6).
CF6-6, CF6-50, and CFM56. The control method used by these
engine families is sector burning. The hardware modifications are
nozzle orifice diameter changes, nozzle support check valves in the
primary fuel delivery of the unfueled sector, fuel manifold, and logic
control.
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Table (6
Engine Costs Associated with the
1981 NME and 1985 Retrofit Standard
(1976 dollars)
Development
Certification
Service
Evaluation
Initial
Production
Non-Recurring
Total
New Engine
Increment
Retrofit
JT9D-7
6.4M
3.5M
2.0M
0.8M
12. 7M
3.6M
46K
JT9D-70
4.5M
3.6M
1.3M
0.5M
9.9M
4K
39K
JT8D
2.7M
2.4M
0.9M
0.3M
6.3M
1.5K
UK
ENGINE FAMILY
JT8D
2.7M
2. AM
0.9M
0.3M
6.3M
1.5K
UK
CF6-6
2.8M
3.0M
1.4M
0.4M
7.6M
5K
50K
CF6-50
2.8M
3.5M
1.4M
0.4M
8.1M
5K
50K
CFM56
2.2M
2.4M
RB211-22
3.3M
3.1M
1.3M
RB211-524
4.1M
3.4M
1.3M
0.3M
4.9M
3.4K
0.2M
7.9M
IK
31K
0.2M
9.0M
IK
34K
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The CFM56 does not require a service evaluation nor a retrofit kit
since it is a new engine without previous field utilization (Table 6).
RB211-22 and RB211-524. These engine families will utilize
minor combustor redesign. Changes are required to the dome and liner.
Rolls Royce has indicated that greater difficulties are expected in
applying the requisite technology to the dash 524 than the dash 22;
therefore, its development cost is somewhat higher (Table 6).
1984 NME. The cost estimate for controlling NOx in addition to HC
and CO are summarized in Table 7. As with the 1981 NME and 1985 retrofit,
differences between engine families of the same manufacturer are attributed
to variations in modification complexity and engine size.
Many of the costs for similar engine families (e.g., CF6-6 and CF6-
50) are identical (Table 7). Although the technology is well defined,
its application to specific families is limited; therefore, the available
data lack sufficient detail to allow discrimination between these families.
The greatest variation is expected to occur in the development category.
Nevertheless, these price differentials may have a tendency to cancel
each other so that the total expenditure by the manufacturer relatively
remains as indicated.
—* "~
The reason one family may have a higher development cost than
another family of similar design produced by the same manufacturer is
quite obvious, unexpected problems, although the reasons for lower costs
are less intuitive. Two of these reasons include: (1) the application
of combustor technology to some engine families is partially complete
since during its development, NASA contracts produced engine demonstrator
hardware; and (2) some degree of commonality exists between similar
engine families; therefore, after initial experience is gained, the
learning curve for subsequent engines is enhanced.
All of the engines in compliance with the NOx standard will require
essentially the same changes: liner, dome, fuel nozzle, fuel supports,
fuel manifold, swirlers, and logic control.
JT9D-7. JT9D-70, JT10D, and JT8D-209. These engine families
are expected to utilize Pratt and Whitney's Vorbix design. This is
considered the most complex staged combustor and is reflected in the
higher levels of most cost components (Table 7).
The JT10D is having its design work done after emission standards ,
were promulgated. This means the staged comgustor will be incorporated
with much less expense than if the engine design was finalized. Furthermore,
at this point many of the costs associated with developing and manufacturing
a new engine have not been incurred. For these reasons, the price
increment for low-emission versus conventional hardware was estimated.
-------
Table 7
i
Engine Costs Associated with 1984 NME Standard
(1976 dollars)
ENGINE FAMILY
JT9D-7
Development
Certification
Service
Evaluation
Initial
Production
Engine
Dedication
12
7
5
4
3
.9M
.8M
.3M
.2M
.2M
JT9D-70
12.
7.
5.
4.
3.
9M
8M
3M
2M
6M
JT10D JT8D-209
5.1M 10.
5.
3.
1.6M 3.
1.
7M
2M
7M
2M
8M
CF6-6
9.6M
6.2M
4.2M
3.8M
3.2M
CF6-50
9.6M
6.2M
4.2M
3.8M
3.6M
CFM56
7.6M
4.3M
2.9M
2.9M
2.2M
RB211-22
10. 3M
6.2M
4.2M
3.8M
3.2M
RB211-524
10. 3M
6.2M
4.2M
3.8M
3.6M
oo
Non-Recurring 33.4M
Total
33. 8M
6.7M 24.6M
27M
27. 4M
19.9M 27.7M
28. 1M
New Engine
29K
29K
23K
19K
22K
22K
15K
22K
15K
-------
-19-
CF-6. CF6-50. and CFM56. General Electric's Double Annular
design will be used by these engine families.
RB211-22 and RB211-524. Information on the type of control
technology is lacking for Rolls Royce engine families. This manufacturer
has not participated in the initial technology development under the
Experimental Clean Combustor Program. Since initial work has not
predisposed them to a specific design, it seems likely that the less
complex double annular combustor would be their choice. Therefore, this
design is assumed with an additional increment for development since
Rolls Royce will benefit less from NASA programs than did General Electric
or Pratt and Whitney. The extent to which they may have been aided by
the British government's National Gas Turbine Establishment is unknown.
ENGINE COST SUMMARY
Within this section engine costs are separated into non-recurring
and recurring categories. Recurring costs are represented by the
selling price increment per engine which reflects increments in the (1)
manufacturing complexity and (2) hardware costs. Neither the selling
price increment nor the retrofit unit cost include pro-rated non-recurring
expenses.
The reader is reminded that important cost elements have been
excluded from this-analysis. These- include probable maintenance-penalties
associated with hot section durability degradation and other expenses to
the airlines as discussed in TSR AC77-02. Therefore, the results of
this section should be regarded only as accounting for a significant
share of the impact brought about by the proposed standards.
Tables 8, 9, and 10 summarize the costs associated with the 1981
NME, 1985 Retrofit, and 1984 NME Standards, respectively.
To derive a more accurate estimate of the total selling price
increment, a 20 percent increase in the in-service fleet numbers (Appendix
B) is used to develop cost information. These extra units reflect the
spare parts inventory of the airlines.
As shown in Table 9, additional non-recurring expenses are not
incurred under the 1985 retrofit since the same hardware is used to meet
the 1981 NME Standard.
OPERATING COSTS
The only operating expense identified as a consequence of the
control schemes is the increment in fuel consumption between regulated
and non-regulated engines. This increment may take two forms. First
although no weight penalty results from the 1981 NME and 1985 Retrofit
Standards, there is a 200-300 pound per engine penalty associated with
-------
-20-
Table 8
The Costs Associated with the 1981
NME Standard (Category 1 and 2 Technology)
(In thousands of dollars)
Non-Recurring Selling Price Total
Selling Price
Model
JT8D-17
JT8D-209
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56"
RB211-22B
RB211-524
TOTAL
Costs
a
6,300
12,700
9,900
7,600
8,100
4,900
7,900
9,000
66,400
Increment /Engine
1.5
1.5
3.6
4.0
5.0
5.0
3.4
1
1
Engines
659
317
149
149
126
271
314
122
122
Increment/Family
989
476
536
596
630
1355
1068
122
122
5,894
Essentially the same combustor as the dash 209, therefore, no additional
non-recur r ing.
-------
-21-
Table 9
The Costs Associated with the 1985 Retrofit Standard
(Category 1 and 2 Technology)
(In thousands of dollars)
Model
JT8D-17
JT8D-2093
JT9D-7
CF6-6
CF6-50
CFM56a
RB211-22B
TOTAL
Retrofit
Unit Cost
' 11
1.5
46
39
50
3.4
31
Total
Engines
3536
362
739
479
125
362
479
Retrofit
Cost/Family
38,896
543
33,994
18,681
6,250
1,230
14,849
114,443
This is a new engine price increment instead of a retrofit kit price.
-------
-22-
Table 10
The Costs Associated with the 1984 NME Standard
(Category 3 Technology)
(In thousands of dollars)
Model
JT8D-209
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56
RB211-22B
RB211-524
JT10DS
CF6-323
RB211-5353
TOTAL
Non-Recurring
Costs
24,600
33,400
33,800
27,000
27,400
19,900
27,700
28,100
6,700
b
c
228,600
Selling Price
Increment /Engine
19
29
29
22
22
15
22
15
23
22
22
Total
Engines
684
1248
1248
886
1724
684
886
1302 =
1120
1120
1118
Selling Price
Increment /Family
12,996
36,192
36,192
19,492
37,928
10,260
19,492
19,530
25,760
24,640
24,596
267,078
See Appendix A.
Same core as CF6-6, therefore, no additional non-recurring.
Q
Same core as RB211-22B, therefore, no additional non-recurring.
-------
-23-
the use of staged combustors to meet the 1984 NME Standard. The additional
vjeight is expected to manifest itself as an increase in the aircraft's
fuel consumption at cruise. The EPA is presently analyzing this problem
to determine its magnitude, therefore, no quantitative expression of the
penalty is included in this study. Second, to meet the proposed standards,
manufacturers will improve the combustion efficiency of their engines,
resulting in an idle specific fuel consumption (SFC) reduction for most
engines.
A re-evaluation of the incremental fuel useage figures published in
TSR AC77-02 on an engine-by-engine basis concluded that the estimates
were excessive. Most engines will experience a 3 percent decrease in
idle fuel consumption rather than a 5 percent decrease. No discrepancy
was found in the 1 percent improvement claimed for the JT8D.
The fuel penalties associated with the General Electric engines in
compliance with the 1981 NME and 1985 Retrofit Standards were also
erroneous. The use of sector burning (category 1) by these engines
causes a 8 percent decrease in component efficiency (instead of the 10
percent previously used), which coupled with the 3 percent benefit in
combustion efficiency (instead of the 5 percent previously used), yields
a 5 percent overall penalty in idle SFC.
Recent information concerning the CFM56 reveals that the CO emission
standards can only be met by an increase in idle thrust from 4 to 6
percent. The EPA estimtes this will result in a 19.6 percent increase
in idle fuel consumption in addition to any other fuel usage increment
brought about by combustion efficiency changes or the use of sector
burning.
The fuel consumption increments associated with the 1981 NME, 1985
Retrofit, and 1984 NME Standards are summarized in Tables 11, 12, and
13, respectively, in 1976 dollars.
General Electric's use of sector burning overwhelms the fuel
savings from other engine families and causes a significant net fuel
consumption increase for the 1981 NME Standard (Table 11). The penalty
associated with GE's sector burning is also significant for the 1985
Retrofit Standard, although the net effect of the standard is an overall
fuel savings (Table 12). The reduction in fuel consumption for each
JT8D-17 engine in the 1985 retrofit fleet is small, but the number of
in-service engines is so large that most of the GE penalty is offset.
The total fuel savings for the 1985 Retrofit Standard is considered
insignificant.
As shown in Table 13, a substantial fuel savings is brought about
by the fleet in compliance with the 1984 NME Standard. The effect of
the CFM56 idle power increase is reflected by a lifetime fuel penalty of
$90,000 per engine.
-------
-24-
Table 11
The Fuel Consumption Increment Associated
with the 1981 NME Fleet
Model
JT8D-209
JT8D-17
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56
RB211-22
RB211-524
TOTAL
In-Service
Engines
264
549
124
124
105
226
262
102
102
$ Saved/Engine
(x 10~J)
9°
9
16
16
-20
-20
-144
18
19
$ Saved/Family
(x 10"b)
2.4
4.9
2.0
2.0
-2.1
-4.5
-37.7
1.8
1.9
-36.7
See Appendix B.
See Reference 3 for derivation.
"See Appendix A.
-------
-25-
Table 12
The Fuel Consumption Increment Associated
with the 1985 Retrofit Fleet
Model
JT8D-17
JT8D-209
JT9D-7
CF6-6
CF6-50
CFM-56
RB211-22
TOTAL
In-Service
Engine
2947
302
616
399
104
302
399
$ Saved/Engine
(x 10 J)
5
7
9
-11
-15
-65
10
$ Saved/Family
(x 10 b)
14.7
2.1
5.5
-4.4
-1.6
-19.6
4.0
0.7
See Appendix B.
See Reference 3 for derivation.
-------
-26-
Table 13
The Fuel Consumption Increment Associated
with the 1984 NME Fleet
Model
JT8D-209°
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM-56C'd
RB211-22
RB211-524
CF6-32d
RB211-535d
JT10Dd
TOTAL
In-Service
Engines
468
102
1040
1040
738
1437
468
102
738
1085
933
932
933
$ Saved/Engine
(x 10~J)
9C
5
16
16
12
12
-90
-51
18
19
iob
14b
17b
$ Saved /Family
(x 10 b)
4.2
0.5
16.6
16.6
8.9
17.2
-42.1
-5.2
13.3
20.6
9.1
13.1
15.9
88.7
See Appendix B.
See Reference 3 for derivation.
Two different annual LTD cycles used. The higher figure represents the twin-
engined narrow-bodied application and the lower figure the B707 and DC-8
retrofit program. See Appendix A.
See Appendix A.
-------
-27-
COST EFFECTIVENESS
The overall cost effectiveness for each of the standards under
consideration is presented in Table 14. The HC and CO cost-effective-
ness figures for the 1981 NME and 1985 retrofit combination are com-
parable, contrary to what would be expected. Primarily, by adding the
retrofit and 1981 NME fleets, the non-recurring costs are amortized over
a greater number of engines, reducing the unit cost and increasing the
emission reductions which substantially enhances the cost effectiveness
of the control strategy. However, the benefit is eroded by fuel penalties
accompanying sector burning.
As pointed out earlier, the cost-effectiveness figures calculated
in this analysis (Table 14) and those presented in TSR AC77-02 (Table
15) are not directly comparable. However, the difference in magnitude
between the two NOx cost-effectiveness numbers requires some explanation.
First, there are significant variations between EPA and industry cost
estimates of the control hardware necessary to meet the proposed stan-
dards. Based on the information accumulated at this time, the EPA is
unable to account for the gross differences in both the non-recurring
costs and selling price increments. It is expected that information
received during the comment period of the NPRM concerning the proposed
standards will help explain these discrepancies.
Second, the FAA fleet projection used in this analysis (Appendix
B), forecasts 3676 more in-service engines for the 1984 NME fleet than
was used in the preceeding analysis. (Part of- this increase is also
accounted for by~ the-*ns& of a 15 year production period -instead of the
10 year period used in AC77-02). This allows the non-recurring costs of
control to be amortized over a greater number of engines, thereby
substantially reducing the cost per engine while increasing the amount
of the pollutants abated and the incremental fuel savings.
The above factors, acting in concert, offset reductions in the fuel
saved by each engine (as discussed in Operating Costs), and substantially
augment the cost effectiveness of the standards under consideration.
The control of HC from aircraft turbine engines in 1981 and 1985 is
more cost effective than that for most other control strategies under
consideration, while the cost effectiveness of controlling NOx emissions
from aircraft turbine engines in 1984 is substantially better (Tables 14
and 16).
-------
-28-
Table 14
The Overall Cost-Effectiveness of the
Standards Under Consideration ($/Ton)
1985 Retrofit
in addition to
Pollutant 1981 NME 1981 NME 1984 NME
HC 260 230 2603
CO 125 110 1253
NOx -450
a The HC and CO values are the same as for 1981 NME.
Table 15
The Overall Cost-Effectiveness of the
Standards Under Consideration
Based on Industry Submittals3 ($/Ton)
1985 Retrofit
in addition to
Pollutant 1981 NME 1981 NME 1984 NME
HC 560 390 560b
CO 220 170 220b
NOx 1316
a TSR AC77-02 (Reference 3).
The HC and CO values are the same as for 1981 NME.
-------
-29-
Table 16
The Overall Cost-Effectiveness of Other
Control Strategies Under Consideration ($/Ton)
Strategy HC N0xa
Stationary Engines (75% control) 340
LDV (1.0 g/mile) 450
Utility Boilers (90% control) 1200
LDV (0.41 g/mile) 2300
Gasoline Handling, Stage 1 100a
Gasoline Handling, Stage 2 700a
LDV (0.41 g/mile) 470a
LDV (IM) Inn°
Neighborhood Dry Cleaners 770
r\
Reference 10.
Reference 15.
-------
-30-
Part II
This portion pf the Discussion was prepared to present an alter-
native cost-effectiveness analysis of the proposed standards. The basis
of each data element used in this alternative is the same as that de-
scribed in Part I; therefore, the discussion of these fundamentals is
not reiterated.
The cost-effectiveness determination described in this part has two
principle components. First, the consequences of promulgating the 1981
NME Standard as the final requirement for all newly manufactured engines
are examined, i.e., 1981 to 1999. Second, since the HC and CO standards
for 1981 NME and 1984 NME are equivalent, the incremental burden of
NOx control is quantified by determining the costs and benefits accrued
beyond those encountered by controlling these two pollutants in 1984
with 1981 technology.
EMISSION REDUCTIONS
The reductions in gaseous emissions for the 1981 NME and 1985
Retrofit Standards are shown in Table 17. The HC and CO lifetime
savings brought about by each standard are combined in this table which
reflects the fact that it is unlikely either standard would be promulgated
separately. This approach is followed throughout the remainder of the
analysis. - _
Table 18 shows the effect pf the 1984 NME Standard on NOx emissions.
It is assumed that the lifetime reductions per engine for HC and CO
brought about by the 1981 NME and 1984 NME Standards are equivalent.
In reality, a difference exists between the ability of 1981 and 1984
hardware to reduce these two pollutants (Table 1 and 3, respectively).
It may be argued that these differences represent additional increments
of control effectiveness and should be allocated to the costs of 1984
technology. However, a preliminary review of this variability found
the total reductions achieved by the two technologies differed by less
than 3 percent in each case. This is well within the uncertainty of
the analysis; therefore, the simplification has no measurable impact on
the final results, and NOx control is retained as the only increment being
analyzed.
ENGINE COST SUMMARY
Table 19 is a summary of the costs associated with the control of
HC and CO. The incremental cost burden for NOx control is summarized in
Table 20. This burden includes the 1981 versus 1984 new engine selling
price differential.
-------
Table 17
Reductions in Gaseous Emissions
Resulting from the 1981 NHE and 1985 Retrofit Standards
1981 NME
1985 Retrofit
Tons/Engine/Lifetime
HC CO
JTSD-17
JT8D-209
JTSO-7
JT9D-70
CF6-6
CF6-50
CFM56
RB211-22B
RB211-524
JT10D3
CF6-32a
RS211-5353
Total
70
65
146
72
87
125
42
386
351
57
71
293
204
130
264
242
174
207
205
447
472
279
143
340
In-service
Engines
549
732
1164
1164
843
1663
730
840
1187
933
933
932
A
Total
Tons/Lifetime (000)
HC CO
38.4
47.6
169.9
83.8
73.3
207.9
30.7
324.2
416.6
56.6
66.2
273.1
1788.3
125
95.2
307.3
281.7
146.7
j
344.2
149.7
375.5
560.3
260.3
133.4
316.9
3096.2
i
B
A
+ B
Total
Tons/Engine/Lifetime
HC CO
38
29
78
NA
46
91
19
206
NA
NA
NA
NA
109
58
141
NA
93
152
92
238
NA
NA
NA
NA
In-Service
Engines
2947
404
616
NA
399
104
404
399
NA
NA
NA
NA
Tons/Lifetime(000)
HC CO
112.0
11.7
48.1
NA
18.4
9.5
7.7
82.2
NA
NA
NA
NA
289.6
321.2
23.4
86.9
NA
37.1
15,8
37.2
95.0
NA
NA
NA
NA
616.6
Total Ton (000)
HC CO
150.4
59.5
218.0
83.8
91.7
217.4
38.4
406.4
416.6
56.6
66.2
273.1
2077.9
446.2
118.6
394.2
281.7
183.8
360.0
186,9
470.5
560.3
260.3
133.4
316.9
3712.8
I
u>
See Appendix A
-------
-32-
Table 18
Incremental Reductions in Gaseous Emissions
Resulting from the 1984 NME Standard
Total
Model
JT8D-209b
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56b
RB211-22B
RB211-524
CF6-32C
RB211-5350
JT10D°
TOTAL
Tons/Engine/Lifetime
NOx
65
37
121
63
87
98
26
15
55
95
71
42
36
In-Service
Engines
468
102
1040
1040
738
1437
468
102
738
1085
933
932
933
10,030
Tons/Lifeti:
NOx
30.4
3.7
125.8
65.5
64.2
140.1
12.2
1.5
40.6
- 103.1
66.2
39.1
33.6
726.0
HC and Co reductions are considered to be equivalent to the 1981
NME Standard's.
Two different annual LTO cycles used. The higher figure represents
the twin-engined narrow-bodied application and lower figure the B708
and DC-8 retrofit program. See Appendix A.
See Appendix A.
-------
Table 19
The Costs Associated with the 1981 NME and 1985 Retrofit
Standards (Category 1 and 2 Technology)_,
(In thousands of dollars)
1981 NME
1985 Retrofit
Model
- - —
JT8D-17
JT8D-209
JT9D-7
JT9D-70
CT6-6
CF6-50
CFM56
RB211-22B
RB211-524
JT10D
CF6-32C
RB211-5350
Non-Recurring
Costs
a
6300
12,700
9900
7600
8100
4900
7900
9000
b
d
e
Selling Price
Increment /Engine
1.5
1.5
3.6
4.0
5.0
5.0
3.4
1
1
b
4
1
Total
Engines
659
1001
1397
1397
1012
1995
998
1008
1424
1120
1120
1118
A
Selling Price
Increment/ Family
989
1502
5029
5588
5060
9975
3393
1008
1424
0
4480
1118
Retrofit
Unit Cost
11
1.5f
46
NA
39
50
3.4f
31
NA
NA
NA
NA
Total
Engines
3536
362
739
NA
479
125
362
479
NA
NA
NA
NA
B
Retrofit
Cost/Family
38,896
543
33,994
NA
18,681
6250
1230
14,849
NA
NA
NA
NA.
A + B
Total
Recurring Costs
39,885
2045
39,023
5588
23,741
16,225
'4623
15,857
1424
0
.4480
1118
TOTAL 66,400 39,566
Essentially the same combustor as the dash 209, therefore, no additional non-recurring.
New engine design negligible impact on cost.
See Appendix A.
114,443
154,009
Same core as CF6-6, therefore, no additional non-recurring.
e Same core as RB211-22B, therefore, no additional non-recurring.
f This is a new engine price increment instead of retrofit kit price.
-------
-34-
Table 20
The Costs Associated with the 1984 NME Standard for NOx
(Category 3 Technology)
(In thousands of dollars)
Model
JT8D-209
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56
RB211-22B
RB211-524
JT10D3
CF6-323
RB211-535S
TOTAL
Non-Recurring
Costs
24,600
33,400
33,800
27,000
27,400
19,900
27,700
28,100
6 r?00
b
c
228,600
Selling Price Total Selling Price
Differential/Engine Engines Differential/Family
18 684 12,312
25
25
17
17
12
21
14
21
18
21
1248
1248
886
1724
684
886
1302
1120
1120
1118
31,200
31,200
15,062
29,308
8,208
18,606
18,228
23,520
20,160
23,478
231,282
See Appendix A.
Same core as CF6-6, therefore, no additional non-recurring.
Same core as RB211-22B, therefore, no additional non-recurring.
-------
-35-
OPERATING COSTS
The fuel consumption increments associated with the 1981 NME and
1985 retrofit fleets are shown in Table 21, while the fuel differential
associated with the 1984 standard is shown in Table 22. When the use of
1981 control technology is extended, the fuel penalty associated with
General Electric's sector burning concept becomes very significant
because of the large production volume associated with the standard.
This not only manifests itself by increasing the cost of controlling HC
and CO, but provides an additional fuel savings when 1984 technology is
introduced.
The net fuel penalty associated with the 1985 retrofit is considered
insignificant relative to the uncertainty of the analysis (Table 21).
Primarily, the fuel saved by the large number of JT8D engines in the
fleet offsets most of the fuel consumption increase brought about by
General Electric1s use of sector burning.
COST EFFECTIVENESS
The overall cost effectiveness for each of the proposed standards
under consideration is presented in Table 23. As expected, a very
significant reduction in the 1981 NME and 1985 retrofit control strategy
cost-effectiveness ratios for HC and CO has resulted. By lengthening the
production time interval of the 1981 standard by- 1-5 years (in reality
the standard is infinite), the non-recurring costs are amortized over
more engines, reducing the unit cost while increasing the reductions in
gaseous emissions.- These benefits overwhelm the accompaning fuel pen-
alty which accounts for about one-fourth of the total HC and CO control
cost.
Also as expected, the cost-effectiveness ratio of the NOx control
strategy increased substantially over the -$450 derived in Part I (Table
14). This increase is a consequence of applying the entire burden of
1984 NME technology to NOx control.
As shown in Tables 23 and 16, controlling HC emissions by a single
newly manufactured engine standard in 1981 and a retrofit standard in
1985 is more cost effective than any of the other proposed control
strategies. Furthermore, the cost effectiveness of controlling NOx
emissions from aircraft engines is comparable to the most cost effective
control strategies under consideration.
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Table 21
The Fuel Consumption Increment Associated
with the 1981 KME and 1985 Retrofit Fleets
1981 NME
1985 Retrofit
In-service
Model Engines
JT8D-209
JT8D-17
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM56
RB211-22
RB211-524
CF6-323
RB2U-5358
JT10D3
732
549
1164
1164
843
1663
730
840
1187
933
932
933
$ Saved/Engine
(x 10"-1)
9
9
16
16
-20
-20
-144
18
19
-16
14
17
TOTAL
A
$ Saved /Family In-Service
(x 10) Engine
6.6
4.9
18.6
18.6
-16.9
-33.3
-105.1
15.1
22.6
-14.9
13.1
15.9
-54.8
3049
302
616
NA
399
104
404
399
NA
NA
NA
NA
$ Saved/Engine
(x 10" J)
5
7
9
NA
-11
-15
-65
10
NA
NA
NA
NA
B
$ Saved /Family
(x 10"6)
15.3
2.1
5.5
NA
-4.4
-1.6
-26.3
4.0
NA
NA
NA
NA
-5.4
A + B
Total $,Saved
(x 10~b)
21. <»
7.0
24.1
18.6
-21.3
-34.9
-131.4
19.1
22.6
-14.9
13.1
15.9
-60.2
See Appendix A.
I
U)
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Table 22
The Fuel Consumption Differential Associated
with the 1984 NME Fleet
1984 NME Baseline
1981 NME Baseline
Differential
Model
JT8D-209a
JT9D-7
JT9D-70
CF6-6
CF6-50
CFM-563
RB211-22
RB211-524
CF6-32b
RB211-535b
JT10Db
In-Service
Engines
468
102
1040
1040
738
1437
468
102
738
1085
933
932
933
Total
$ Saved
per Engine
(x 10 J)
9
5
16
16
12
12
-90
-51
18
19
10
14
17
A
$ Saved
per Family
(x 10 b)
4.2
0.5
16.6
16.6
8.9
17.2
-42,1
-5.2
13.3
20.6
9.1
13.1
15.9
88.7
$ Saved
per Engine
(x 10 3)
9
5
16
16
-20
-20
-144
-81
18
19
16
14
17
B
$ Saved
per Family
(x 10~b)
4.2
0.5
16.6
16.6
-14.8
-28.7
-67.4
-8.3
13.3
20.6
-14.9
13.1
15.9
-59.8
A + B
§ Saved
per Family
(x 10~b)
0
0
0
0
23.7
45.9
25.3
3.1
0
0
24.0
0
0
122.0
Two different annual LTO cycles used. The higher figure represents the twin-engined narrow-bodied application
and the lower figure the B707 and DC-8 retrofit program. See Appendix A.
See Appendix A.
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-38-
Table 23
The Overall Cost-Effectiveness of the
Standards tinder Consideration ($/Ton)
1985 Retrofit
in addition to
Pollutant 1981 NME 1984 NME
HC 70 70
CO 40 40
NOx - 470
Table 16
The Overall Cost-Effectiveness of Other
Control Strategies Under Consideration ($/Ton)
Strategy HC N0xa
Stationary Engines (75% control) 340
LDV (1.0 g/mile) 450
Utility Boilers (90% control) 1200
LDV (0.41 g/mile) 2300
Gasoline Handling, Stage 1 100a
Gasoline Handling, Stage 2 700
LDV (0.41 g/mile) 470*
LDV (IM)
Neighborhood Dry Cleaners 770
Reference 10.
Reference 15.
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—39—
CONCLUSIONS
The cost-effectiveness information presented in this report was
prepared from existing EPA cost data. Important uncertainties exist at
this time; therefore, any conclusions must be interpreted with care.
In most cases, the differences between industry and EPA cost
estimates of the requisite control hardware are significant and un-
accounted for. It is expected that information received during the
comment period of the NPRM concerning the proposed revisions in the
standards will help explain these discrepancies.
The consequences of alternative control strategies and cost accounting
methods were analyzed. The impact of the proposed standards on incremental
fuel usage at idle varied under the two alternatives examined, although
the results were generally consistent.
A significant overall fuel consumption penalty was calculated for
engines in compliance with the 1981 NME Standard. The 1985 Retrofit
Standard typically had an insignificant net effect on fuel consumption.
A substantial fuel savings was associated with the 1984 NME Standard.
Depending on the method of determination, controlling EC emissions
from gas turbine aircraft engines to the levels prescribed by the 1981
NME Standard or in conjunction with the 1985 Retrofit Standard was found
to be more cost effective than all, or most of the other control strategies
under consideration. The cost effectiveness of-NOx control under the
1984 NME Standard was substantially better than, or comparable to the
most cost effective of the other proposed control strategies for mobile
and stationary sources.
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-40-
REFERENCES
1. Bastress, E.K., R.C. Baker, C.F. Robertson, R.D, Siegel, and G.E.
Smith. 1971. Assessment of aircraft emission control technology.
Northern Research and Engineering Corporation. Report No. 1168-1.
EPA Contract No. 68-04-0011.
2. Arthur D. Little, Inc. 1975. Continuing assessment of aircraft
control technology. Draft. EPA Contract No. 68-03-2007. Emission
Control Technology Division, Office of Mobile Source Air Pollution
Control, Environmental Protection Agency, Ann Arbor, Michigan.
3. Wilcox, R.S. and R. Munt. 1977. Cost-effectiveness analysis of
the proposed revisions in the exhaust emission standards for new
and in-use gas turbine aircraft engines based on industry submittals.
TSR AC77-02. Emission Control Technology Division, Office of
Mobile Source Air Pollution Control, Environmental Protection
Agency, Ann Arbor, Michigan.
4. Civil Aeronautics Board. 1977. Aircraft operating cost and performance
report. Volume XI. Economic Evaluation Division, Bureau of
Accounts and Statistics, Washington, D.C.
5.' Munt, Rv W-.. 1978. U.S. aircraft fleet projection and engine
inventory to the year 2000. TSR AC78-02. Emission Control
Technology Division, Office of Mobile Source Air Pollution Control,
Environmental Protection Agency, Ann Arbor, Michigan,
6. Federal Aviation Administration. 1977. Fleet projection to year
2000. Office of Aviation Policy, Washington, D.C. (Unpublished).
7. Johnson, R. and P. Hardy, United Airlines. 1977. Conference of 8
December 1977 with William H. Houtman, Emission Control Technology
Division, Office of Mobile Source Air Pollution Control, Environmental
Protection Agency, Ann Arbor, Michigan.
8. Jet Avion, Inc. 1977. Price list for JT8D replacement parts.
Hollywood, Flordia.
9. TenZythoff, H.J. 1975. Pratt and Whitney JT3D engines reduced
smoke emission requirement impact of project, timing of project.
Engineering Report R47-1008. American Airlines, Rulsa, Oklahoma.
10. Department of Transportation, Interagency Task Force on Motor
Vehicle Goals Beyond 1980. 1976. Air quality, noise and health.
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-41-
11. Titcomo, G.A., Pratt and Whiteny Aircraft Group. 1977. Letter of
8 November 1977 to E.O. Stork, Office of Mobile Source Air Pollution
Control, Environmental Protection Agency, Washington, B.C.
12. Brizendine, J.C., McDonnell Douglas Corporation. 1977. Letter of
25 October 1977 to E.O. Stork, Office of Mobile Source Air Pollution
Control, Environmental Protection Agency, Washington, D.C.
13. Munt, R. And E. Danielson. 1976. Aircraft technology assessment -
status of the gas turbine program. Emission Control Technology
Division, Office of Mobile Source Air Pollution Control, Environmental
Protection Agency, Ann Arbor, Michigan.
14. Aviation W. 1977. Boeing nearing new transport design. 107(19:
68-69.
15. Angus, R. M. 1977. Draft economic energy impact assessment for
alternatives to national air quality standards for photochemical
oxidants. Office of Air Quality Planning and Standards, Strategies
and Air Standards Division, Environmental Protection Agency, Research
Triangle Park, North Carolina.
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A-l
APPENDIX A
The following information is necessary to complete the derivation
of emissions reduction and fuel savings as presented in Appendix B of
TSR AC77-02.
Engine Parameters ^
JT8D-209:
1. Rated thrust is 18,500 pounds;
2. Impulse over the cycle is 1684 pound-hours;
3. Baseline EPAPs based on fuel flow and pressure ratio
corrections from JT8D-17 data are HC 2.3, CO 8.5, and NOx 6.4
pounds per 1000 pound-hours impulse over the LTD cycle; and
4. Regulated EPAPs are HC 0.2, CO 4.4, and NOx 4.3 pounds per
1000 pound-hours impulse over the LTO cycle; and
5. Mf at idle is 1090 Ibms/hr.
CF6-32:
1. All the necessary information is based on derivations for
the CF6-6, which has the same core, by using a correction
factor based on the rated thrust of the engines (CF6^32 at
32,000 Ibs * CF6-6 at 39,000 Ibs = 0.82).
RB211-535:
1. Same method as used for the CF6-32 above, only the correction
factor is based on the RB211-22B, which has the same core as
the RB211-535 (32,000 Ibs T 42,000 Ibs = 0.76).
JT10D:
1. Same method as used for the CF6-32 above, only correction
the factor is based on the CFM56 without the penalties associated
with sector burning and increase idle power. Both engines are
a low emission design (30,000 Ibs * 22,000 Ibs = 1.36).
CFM56:
1. The baseline M idle has been increased to 714 Ibs/hr from
the 600 Ibs/hr published in TSR AC77-02. To achieve the CO
level under each standard, the idle thrust must be increased
from 4% to 6%, resulting in a corrected M idle of 854 Ibs/hr.
The use of sector burning to comply with the 1981 NME and 1985
Retrofit Standards has an associated 5% penalty in addition to
that brought about by the thrust idle increase.
-------
A-2
LTO Cycles
A re-evaluation of the LTO cycle figures used in TSR AC77-02
to represent the number of operations an engine experiences in its
useful life found that the figure used to reflect the retrofit of the
B707-DC-8 fleet was inappropriate. The long-haul operational nature of
these aircraft precludes a high number of LTOs. Therefore, a review
of the CAB data necessitated a change from 2455 to 1380 LTOs per year
for the engines used in the B707 and DC-8 retrofit fleet (JT8D-209 and
CFM56).
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B-l
APPENDIX B
Fleet Projection and Engine Inventory
There are three aircraft fleets of interest, each associated with
one of the three dates of the standards: 1981 (NME: HC, CO), 1984
(NME: NOx), and 1985 (Retrofit for pre-1981 engines to 1981 NME levels).
The associated engine inventories are obtained from Reference 1, Table
VII. The derivation of this inventory projection contains certain
important assumption that are worth noting here:
(1) The original fleet projection comes from an unpublished forecast
made by the FAA (to the year 2000), which apparently was derived from
the same study that produced Reference 2;
(2) The introduction of new aircraft models are accounted for in
the following manner: the 1981 NME fleet includes the DC-9-S80 and
B737-300, and the 1984 NME fleet includes 2 and 3-engined versions of
the B7S7, L1011-600, and Twin DC-10;
(3) The B707 and DC-8 will remain in the fleet in declining
numbers, but will be re-engined by 1985 with the CFM56 and JT8D-209
equally to meet environmental regulations;
(4) The all new B7S7 will be powered by the "clipped fans" engines,
CF6-32 and RB211-535, and by the JT10D (this mix reflecting the state of
uncertainty at this time); and
(5) Aircraft are expected to be in service 15 years, regardless of
category or type, this corresponding roughly to the depreciation period.
In addition, there is the difficulty of specifying an inventory for
the 1984 standard which is indefinite in duration. For the purposes of
costeffectiveness estimating, it is postulated that a reasonable number
of engines to consider are those over which the R & D, certification,
and intital tooling costs (i.e., the fixed costs) would be amortized.
Beyond this number, the cost would be reduced and the cost effectiveness
increased unless, of course, those engine types are replaced by newly
certification engine for which some of the fixed cost burden is repeated.
It is assumed here that the write-off period of the fixed costs
constitutes 15 years of production (i.e., to 1999). It may be argued
that this is an unlikely long period inasmuch as most of the engines in
question were originally configured in the 1960s. Nonetheless, the high
cost of development, the refinement of technology, and the timing of new
technology (e.g., the NASA Energy Efficient Engine program) suggest that
the present engines and their derivatives will be around for a long
time. Thus, 15 years is used.
Table B-l presents the projection of the engine inventory.
-------
B-2
Table B-l
Engine Inventory
Engine
JT8D-17
JT8D-209
JT9D-7
JT9D-70
JT10D
CF6-6
CF6-50
CF6-32
CFM56
RB211-22B
RB211-524
RB211-535
1985 Retrofit
2947
302
616
0
0
399
104
0
302
399
0
0
Standard
1981 NME
549
264
124
124
0
105
226
0
262
102
102
0
1984 NME
0
570a
1040
1040
933
738
1437
933
570a
738
1085
932
These numbers include 102 engines newly built in 1984 to be retrofitted onto
the B707 and DC-8 fleet for compliance with the 1985 Retrofit Rule.
Although these engines exceed the requirements specified by the rule,
their date of manufacture forces them to comply with the more stringent
standard.
-------
B-3
References
(Appendix B)
1. Hunt, R. W. 1978. U.S. aircraft fleet projection and engine inventory
engine inventory to the year 2000. TSR AC78-02. Emission Control
Technology Division, Office of Mobile Source Air Pollution Control,
Environmental Protection Agency, Ann Arbor, Michigan.
2. Department of Transportation. 1977. FAA aviation forecasts,
fiscal years 1978-1989. AVP-77-32, Federal Aviation Administration,
Washington, D.C.
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