Air Force F-15EX Fighter Program
Updated September 2, 2020
Air Force F-15EX Fighter Program
In FY2020, the Trump Administration proposed to buy
Why is the Air Force requesting
eight F-15EX aircraft for $1.1 billion, the first installment
F-15EXs?
toward a planned initial buy of 144 planes. Subsequently,
Congress authorized $985.5 million and appropriated $1.05
Air Force officials have offered numerous justifications for
billion for the program. The Administration’s FY2021
the F-15EX:
budget requests $1.27 billion for 12 more F-15EXs; the
plan set forth in FY2020 had called for 18 in FY2021.
The Air Force is engaged in upgrades to its existing
F-15 fleet. While costing more per aircraft than
This acquisition represents a change from previous Air
modernizing legacy F-15s, a new F-15EX would yield
Force plans to procure only stealthy “fifth-generation”
more future life. Replacing the older, 1980s-era F-15Cs
fighter aircraft. What is an F-15EX, and why might the Air
with F-15EX could also enable the Air Force to avoid
Force have changed plans?
the cost of some or all of those upgrades. “The Air
What is an F-15EX?
Force has tried to retire its 250 aging F-15Cs and two-
seat F-15Ds over the years due to structural issues with
The Air Force received its first F-15 Eagle air superiority
the aircraft, including most recently in 2017. Now,
fighter in 1974. Subsequently, the F-15 evolved to
instead of paying to upgrade the older aircraft in the
encompass more roles, most notably with the deployment
fleet, the Air Force hopes to use that money to buy
of the F-15E Strike Eagle in 1989. The F-15E added
Boeing’s F-15EX.”
substantial air-to-ground capability, including a second
cockpit for a weapons systems operator. The Air Force has
Buying F-15s, according to the Air Force, is an
453 F-15s of all variants, the last of which was ordered in
economical way of reaching the service’s goals for
2001. Since then, F-15s have been continuously produced
fighter fleet size and average age. “Gen. James ‘Mike’
for a variety of international customers, including (among
Holmes, head of Air Combat Command, told reporters
others) Israel, Saudi Arabia, and Japan.
in February that purchasing the F-15EX could be the
‘affordable answer’ to meeting the Air Force’s goal of
Figure 1. F-15EX Concept
acquiring 72 new fighter jets each year.”
F-15s could also cost less to operate over time than
fifth-generation fighters like the F-35. (The per-hour
cost of F-15s is fairly well established, while there is
less real-world experience with the F-35 fleet; a direct
comparison is difficult.)
Because the Air Force already operates F-15s, transition
to the F-15EX could be comparatively easy. “We made
the determination to buy F-15EXs so that we could keep
our readiness at a higher level and meet the capacity
need that we had for those fourth generation platforms.
That is important from a readiness perspective because
the time to transition from an F-15C to an F-15EX we
estimate at 3 to 6 months, while the time to transition
from an F-15C to an F-35 could be anywhere from 18 to
36 months and would require MILCON and other
Source: Boeing.
attributes that are not in our budget.”
Current F-15s have stronger airframes and more advanced
sensors, processors, and flight control systems than those in
F-15EX procurement helps maintain a competitive
the U.S. fleet. Many also include conformal fuel tanks to
fighter aircraft industrial base. Currently, Boeing and
extend range and increase payload. The proposed F-15EX
Lockheed Martin are the prime contractors supplying
would be based on the most advanced Eagles, currently
fighter jets to the Department of Defense. A National
entering production for Qatar, which first flew on April 14,
Defense magazine report stated
2020. F-15EXs would add radar and other subsystems
unique to the United States. Boeing says that the F-15EX
After the decision was made to continue with a
would have 70% parts commonality with existing U.S.
mix of fourth- and fifth-generation aircraft,
F-15s.
“the conversation then turned to how are we
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Air Force F-15EX Fighter Program
going to maintain a robust industrial base,” a
Although the F-15EX acquisition was proposed as a sole-
Pentagon official, who declined to be named,
source contract outside of the normal requirements-
official told reporters.
definition process, Congress acted to retroactively require
much of the same documentation. The FY2020 National
“For the future of the Department of Defense,
Defense Authorization Act and the explanatory statement
it’s going to be good to have multiple providers
accompanying the FY2020 Defense Appropriations Act
in the tactical aircraft portfolio … and that’s
require the Secretary of the Air Force to provide an F-15EX
what led our way into the F-15EX decision,” he
acquisition strategy, cost and schedule estimates, and
added.
strategies for test and evaluation, logistics, and post-
production fielding. The appropriations statement also
Former Air Force Secretary Heather Wilson said that the
requires a capability production document and life-cycle
Air Force did not request the F-15EXs in its initial FY2020
sustainment plan.
budget submission. This proposal appears to have been
added by the Office of the Secretary of Defense during the
Initial Basing
budget build process, without a request for proposals or
explanation. However, Wilson and other Air Force officials
On August 14, 2020, the Air Force announced that the
subsequently advocated for the F-15EX. “‘We are seeing a
initial F-15EX base would be Kingsley Field, OR, where a
decline in the number of fighters available, the increase in
training unit will stand up in 2022. Portland ANGB, OR,
the average age of those fighters, and if we look at the
will be the first operational base, beginning in 2023. Flight
whole system and the whole capacity over the next 10 to 20
tests will begin at Eglin AFB, FL, in 2021.
years, one of the airframes that is not going to make it is the
F-15C,’ Wilson said.” “We need to replace those F-15Cs
Possible Questions
with something.” Gen. Arnold Bunch added, “We have now
looked at … what it takes to modernize that capability up in
Should acquisition of new fighters be a competitive
an F-15C, and the determination we made was that was not
what we needed to do.”
procurement?
Does the F-15EX replace the F-35?
What are the relative costs of upgrade and modernizing
existing F-15s as opposed to buying new ones? How
many flight hours does the Air Force expect to get from
The Air Force has been at pains to emphasize that the F-35
the jets in each case?
and F-15EX are not rivals, but complementary. The F-35
brings superior stealth and sensor fusion; the F-15 can carry
If new F-15EXs are purchased, would the Air Force
more payload. (Air Force officials describe this as the
difference between “capability” and “capacity.”) The
retire older F-15s rather than upgrading them? How
many upgrades would be foregone for each new F-15
message of different missions can also be seen in the
purchased?
emphasis on F-15EX as an alternative to modernizing
existing F-15s in their existing roles.
How does the replacement of F-15s fit with the Air
Force’s declared goal of growing to 386 squadrons?
Given a fixed Air Force budget topline, however, increases
in one program require cuts in others. According to Air
If stealthy aircraft are only required in a given conflict
Force Chief of Staff General David Goldfein, “If we had
until the air defenses are taken down, which allows
the money, those would be 72 F-35s. But we’ve gotta look
older-technology aircraft to operate with impunity, does
at this from a cost/business case.” He also noted, “We are
it make sense to size the buy of fifth-generation aircraft
absolutely adamant that the F-35 program, the program of
using requirements for the early phases of conflict?
record, absolutely stays on track and we don't take a dime
out of the F-35.”
What is DOD’s commitment to completing the planned
buy of F-35As?
While maintaining the planned purchase of 48 F-35As in
FY2020, the Administration reduced its projected buy by
How does the F-15EX fit with the current National
18 aircraft through FY2023 in its FY2020 and FY2021
Military Strategy emphasizing capability against
budget submissions. This may not be a direct correlation,
sophisticated adversaries?
but has led some to see a tension between the two
programs.
Jeremiah Gertler, Specialist in Military Aviation
IF11521
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Air Force F-15EX Fighter Program
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