The Cost of 

Replacing Today’s 

Army Aviation 

Fleet

MAY 2019

CONGRESS OF THE UNITED STATES

CONGRESSIONAL BUDGET OFFICE
Notes

The years referred to in this report are federal fiscal years, which run from October 1 to 

September 30 and are designated by the calendar year in which they end.

All costs are expressed in 2018 dollars. For the years before 2018, costs are adjusted for 

inflation with the gross domestic product price index from the Bureau of Economic 

Analysis. Costs for years after 2018 are adjusted for inflation with the Congressional 

Budget Office’s projection of that index.

On the cover: The drawing depicts, from top to bottom, an H-47 Chinook, an 

H-60 Black Hawk, and an AH-64 Apache.

www.cbo.gov/publication/55180
Contents

Summary 1

The Cost of Replacing Today’s Fleet 1

How CBO Made Its Projections 4

Future Vertical Lift Aircraft 5

Projected Procurement Schedules and Costs 6

Age of Fleets 6

Uncertainties 6

Uncertainty About the Future Vertical Lift Program 7

Uncertainty About Chinook Modernization 8

Appendix: Composition of the Army’s Current Fleet and CBO’s Estimate of Replacement Costs 11

List of Tables and Figures 15

About This Document 16

The Cost of Replacing Today’s Army Aviation Fleet 

Summary

The U.S. Army has about 4,300 piloted aircraft, most 

of which are helicopters (also known as rotary-wing 

aircraft). Three large, high-value fleets—the H-60 Black 

Hawks, AH-64 Apaches, and H-47 Chinooks—account 

for most of the helicopters, and their eventual replacement dominates the Army’s future procurement costs. In 

this report, the Congressional Budget Office estimates 

the costs of replacing those helicopters and the Army’s 

other aircraft through 2050 if the service implemented 

its current plans and, for aircraft with no announced 

replacement plans, if they were replaced when they 

reached the end of their typical service life.1

• Replacement Costs. CBO projects that the annual 

cost of replacing the aircraft in the Army’s current 

fleet would decline during the 2020s, from about 

$4 billion in 2018 to about $1.5 billion in 2027. 

It would then rise to a peak of about $4.7 billion 

in 2032 before drifting downward between 2035 

and 2045. Because the Army made considerable 

investments in aircraft between 2007 and 2016, 

relatively few aircraft are near the end of their service 

life, reducing the number of aircraft to be replaced 

during the 2020s.

• Methods. CBO’s projections are based on publicly 

articulated procurement plans for some aircraft 

and, for aircraft without such plans, on their typical 

retirement age; the projections do not take into 

account the costs of development, operations and 

maintenance, modifications, or personnel associated 

with aircraft.

• Future Vertical Lift Plans. The Army’s Future Vertical 

Lift (FVL) program is developing new technologies 

to include in aircraft in the late 2020s to early 2030s: 

the Future Long-Range Assault Aircraft (FLRAA) 

for transport and the Future Attack Reconnaissance 

1. CBO undertook a similar analysis of Air Force aircraft. See 

Congressional Budget Office, The Cost of Replacing Today’s Air 

Force Fleet (December 2018), www.cbo.gov/publication/54657.

Aircraft (FARA) for improved armed reconnaissance 

capabilities. The FLRAA is expected to replace 

today’s Black Hawk helicopters, and the FARA may 

eventually replace today’s Apaches when they are 

retired.

• Uncertainty. CBO’s estimates are subject to several 

sources of uncertainty. The characteristics of the two 

FVL aircraft have not been finalized, and technical 

challenges could change schedules, characteristics, or 

costs. Additionally, the Army has recently indicated 

that it may substantially change or cancel plans to 

modernize the CH-47F Chinook helicopters that are 

included in CBO’s projection. 

The Cost of Replacing Today’s Fleet

According to data the Army provided to CBO, as of 

April 15, 2018, the Army’s aviation fleet consisted of 

21 different types of aircraft, including the following: 

• 2,279 Sikorsky H-60 Black Hawk helicopters, most 

of which are utility transports;

• 744 Boeing AH-64 Apache heavy attack helicopters, 

which are also used for armed reconnaissance 

missions;

• 423 Boeing H-47 Chinook heavy-lift cargo 

helicopters;

• 411 Airbus UH-72 Lakota light utility helicopters; 

and

• 92 Beechcraft C-12 Huron fixed-wing passenger 

turboprop airplanes (plus an additional 

30 RC-12 reconnaissance airplanes).2

2. The H-60 Black Hawks include EH-60, HH-60, MH-60, and 

UH-60 helicopters. The H-47 Chinooks include both CH-47 

and MH-47 helicopters. For more details on the Army’s force 

structure, see Congressional Budget Office, The U.S. Military’s 

Force Structure: A Primer (July 2016), Chapter 2, www.cbo.gov/

publication/51535.
2 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET may 2019

Although those aircraft range widely in age, many Army 

aircraft are fairly new, having been acquired or remanufactured within the past 10 years (see the upper panel in 

Figure 1).3

CBO assigned each type of aircraft in the current 

Army fleet an estimated replacement unit cost and 

then projected the total replacement cost for each 

aircraft type by multiplying the per-aircraft replacement cost by the number of aircraft in that fleet (see the 

3. The Army often remanufactures helicopters, rebuilding the 

aircraft using the original metallic chassis. The Army assigns new 

tail numbers to remanufactured helicopters, so they appear in 

the data CBO analyzed as new aircraft. CBO cannot tell whether 

a given helicopter is new or remanufactured, so aircraft age is 

measured from either acquisition or remanufacture date.

appendix). For example, the December 2017 CH-47F 

Modernized Cargo Helicopter (CH-47F Block II) 

Selected Acquisition Report (SAR) indicated an average 

procurement unit cost of $28 million in 2017 dollars, 

or about $29 million in 2018 dollars. Assigning each of 

the Army’s 423 H-47 Chinooks that average replacement 

cost resulted in an estimated overall fleet-replacement 

cost of $12.2 billion.4 Not surprisingly, the Army’s 

largest fleets—the H-60 Black Hawks, AH-64 Apaches, 

and H-47 Chinooks—had the highest total replacement costs. The aircraft with the highest replacement 

4. That technique does not imply that Chinook aircraft in the 

current fleet are worth $29 million today. Rather, replacing 

today’s (Block I) Chinooks with Block IIs would have an average 

procurement unit cost of that amount.

Figure 1.

Age and Replacement Cost of the Army’s Fleet, 2018

0

200

400

600

800

1,000

1,200

0−4 5−9 10−14 15−19 20−24 25−29 30−34 35−39 40−44 45−49

0

10

20

30

40

50

0−4 5−9 10−14 15−19 20−24 25−29 30−34 35−39 40−44 45−49

Billions of 2018 Dollars

Entered service Aircraft Age in 2018 (Years)

in 2018

Entered service

in 1969

Number of Aircraft

Replacement Cost

Source: Congressional Budget Office, using data from the U.S. Army.

Age is measured in years since acquisition or remanufacture. The figure does not include data for MQ-1C Gray Eagles because ages for those aircraft 

were not available.

Those fairly new or recently 

remanufactured aircraft are in 

the cohorts with the highest 

replacement costs.

Many of the Army’s aircraft have 

been acquired or remanufactured 

within the past 10 years.
may 2019 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET 3

costs tend to be the newest ones (see the lower panel in 

Figure 1).

The Army’s total annual budget for procuring aircraft 

increased markedly starting in 2007 (see Figure 2). 

Measured in 2018 dollars, that budget was $1.9 billion 

in 2000 but rose to a peak of $8.3 billion in 2011. The 

budget declined in most years after 2011, falling to 

$4.1 billion in 2018. Aircraft procurement represented 

about 15 percent of the Army’s total procurement budget 

over the 2000–2018 period; ground vehicles such as 

tanks and trucks accounted for the largest portion of the 

Army’s total procurement budget over that period. The 

procurement budget for aircraft has generally been less 

than 3 percent of the Army’s overall budget, much of 

which goes to military and civilian personnel costs.

CBO projects that the costs of replacing the aircraft in 

the Army’s current fleet would decline in most years 

through the 2020s, dropping to about $1.5 billion in 

2027 before rising above $4 billion per year through 

the early-mid 2030s as procurement for the two FVL 

programs ramped up (see Figure 3). Those costs would 

decline between 2035 and 2045 and remain relatively 

stable thereafter, at around $3 billion per year, until 

2050. The projected annual costs for 2019 to 2050 are 

below the average budget for procurement of Army 

aircraft over the 2010–2018 period but similar to the 

average budget over the 2000–2009 period. 

The $4.7 billion peak in 2032 is composed of funding for the FARA ($1.4 billion), which would initially 

augment the Army’s current armed reconnaissance 

capabilities and possibly replace the AH-64 Apache 

later; the FLRAA ($1.3 billion), which would replace 

the H-60 Black Hawk; projected replacement of the 

fixed-wing MQ-1C Gray Eagle ($1.0 billion); and 

modernization of the CH-47 Chinook ($0.7 billion) 

(see Figure 4).5 Apache procurement would end in 2025 

before FARA procurement began in 2028, but procurement of Black Hawks (ending in 2035) and FLRAAs 

(beginning in 2030) would overlap. 

Although CBO’s projections address changes in the 

Army’s fleet through 2050, the agency formed no 

judgment about whether the aircraft procurements in its 

analysis are necessary or appropriate. Instead, this report 

projects the costs to procure the aircraft in the Army’s 

5. Currently, Apaches carry out their original heavy attack missions 

as well as reconnaissance or light attack missions that OH-58D 

Kiowa Warrior helicopters performed before the Army retired 

those aircraft in 2012. The Army has not determined whether it 

will retire the Apaches as FARA squadrons enter the force around 

2030 or simply transition them back to their original heavy 

attack role.

Figure 2.

The Army’s Budgets for Procuring Aircraft, 2000–2018

Billions of 2018 Dollars

Average Budget for Procuring Aircraft,

2010–2018

Average Budget for Procuring Aircraft,

2000–2009

Budget for Procuring Aircraft

0

3

6

9

2000 2003 2006 2009 2012 2015 2018

Source: Congressional Budget Office, using data from the U.S. Army.

The Army’s budgets for procuring 

aircraft increased markedly 

starting in 2007.
4 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET may 2019

publicly articulated plans and to replace other aircraft 

on a one-for-one basis when they reach the end of their 

service life.6

How CBO Made Its Projections

CBO used two complementary approaches to project 

changes in the Army’s fleet and the costs of aircraft procurement associated with those changes. 

First, for the Army’s three major aviation acquisition 

programs (H-60, AH-64, and H-47), CBO developed 

detailed procurement cost projections. CBO used information from Department of Defense–issued SARs that 

summarize projected development schedules, purchase 

quantities, and costs for the Congress each year. The 

agency then supplemented those SARs with its own 

projections of program costs and schedules based on the 

Army’s general plans:

• The December 2017 UH-60M Black Hawk 

Helicopter SAR gives quantities and estimates of 

procurement costs through 2028.7 With input 

6. The Army told CBO that it does not plan to replace its fixedwing C-20, C-23, and C-27 aircraft or its rotary-wing OH-58 

and UH-1H aircraft. Hence, CBO projects no replacement costs 

for those aircraft (see Table A-3 on page 14).

7. The five-year plan submitted with the Army’s budget request for 

2020 included fewer UH-60 purchases from 2020 through 2024 

from the Army, CBO projected that procurement 

of replacements for Black Hawks (the FLRAA) 

would begin in 2030. CBO based its estimate of 

the FLRAA’s procurement costs on the costs of 

current transport aircraft but adjusted the total to 

account (as described below) for specific performance 

characteristics that the Army has proposed for the 

FLRAA.

• The December 2017 AH-64E Apache Remanufacture 

SAR gives quantities and procurement cost estimates 

through 2025. CBO projected that procurement of 

an aircraft the Army is developing to augment its 

armed reconnaissance capabilities (the FARA) would 

eventually be extended to also replace Apaches when 

they reached the end of their service life.8 With 

input from the Army, CBO projected procurement 

of 30 FARAs per year but made no judgment about 

which ones would augment the current force and 

which would replace retiring Apaches. CBO based 

than were indicated in the December 2017 SAR. If that program 

changed, it would reduce CBO’s projection of costs through 

2028; see “Uncertainties” on page 6 for details on how that 

change could affect CBO’s projection.

8. The Army might instead limit FARA purchases to the number 

needed for armed reconnaissance missions and develop a new 

aircraft that is larger than the FARA to replace the Apache for 

heavy attack missions. That approach could result in costs that 

are higher than CBO’s projections.

Figure 3.

Projected Army Costs for Procuring Aircraft, 2019–2050

Billions of 2018 Dollars

Average Budget for Procuring Aircraft, 2010–2018

Average Budget for Procuring Aircraft,

2000–2009

Projected Costs for Procuring Aircraft

0

3

6

9

2015 2020 2025 2030 2035 2040 2045 2050

Source: Congressional Budget Office.

According to CBO’s projections, 

the costs of procuring Army 

aircraft would decline in the early 

to mid-2020s, rise through the 

early to mid-2030s, and decline 

after 2035. Annual costs would 

remain below the average budget 

the service received from 2010 

to 2018.
may 2019 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET 5

its estimate of the FARA’s procurement costs on the 

costs of current attack and armed reconnaissance 

aircraft but adjusted the total to account for specific 

performance characteristics that the Army has 

proposed for the FARA.

• The December 2017 CH-47F Modernized Cargo 

Helicopter (Block II) SAR gives quantities and 

procurement cost estimates through 2043. For the 

years after 2043, CBO projected that the Army 

would replace H-47s in the annual quantities in 

which the aircraft were procured 25 years earlier.9

Second, CBO projected that the Army would retire 

and replace other aircraft when they reached specified 

ages (see the appendix). For example, as of April 15, 

2018, the Army had 28 UC-35 medium-range, fixedwing transport aircraft ranging in age from 16 years to 

21 years. If the Army retired those aircraft at age 35, the 

oldest UC-35s would be retired in 2032 and the newest 

would be retired in 2037. 

With input from the Army, CBO estimated the unit 

costs for procuring replacement aircraft.10 New aircraft 

typically have higher procurement unit costs than the 

aircraft they replaced, reflecting their increased capability. 

CBO projected that the new or remanufactured aircraft 

will enter service two years after appropriations are 

enacted for procurement, which is consistent with the 

Department of Defense’s experience.

Future Vertical Lift Aircraft

For the past several years, the Army has been investing 

in new technologies that would enable improved performance for its future aircraft. The Army’s FVL program has been exploring technologies such as increased 

use of composite materials, tilt-rotor propulsion, and 

double coaxial rotors that may sizably increase flight 

range, speed, and endurance relative to today’s Army 

9. The five-year plan submitted with the Army’s budget request 

for 2020 included fewer than half of the Block II Chinook 

purchases from 2020 through 2024 that were indicated in 

the December 2017 SAR. Army officials have stated that 

Block II purchases may be further deferred, curtailed, or canceled 

depending on factors such as availability of funds and progress 

with the FVL program.

10. Average procurement unit cost is total program procurement 

cost divided by the number of units procured. See Defense 

Acquisition University, “Average Procurement Unit Cost” 

(accessed May 7, 2019), https://go.usa.gov/xEVFb.

Figure 4.

Projected Army Costs for Procuring Selected 

Aircraft, 2019–2050

Billions of 2018 Dollars

AH-64

Apache

UH-60

Black Hawk

FLRAA

FARA

CH-47

Chinook

Fixed-Wing

Aircraft

0

0.5

1.0

1.5

2.0

2015 2020 2025 2030 2035 2040 2045 2050

0

0.5

1.0

1.5

2.0

2015 2020 2025 2030 2035 2040 2045 2050

0

0.5

1.0

1.5

2.0

2015 2020 2025 2030 2035 2040 2045 2050

Apache/FARA

Black Hawk/FLRAA

Other Aircrafta

Source: Congressional Budget Office.

FARA = Future Attack Reconnaissance Aircraft; FLRAA = Future LongRange Assault Aircraft.

a. CBO projects additional costs for other rotary-wing aircraft in two 

years: $36 million in 2019 and $94 million in 2050.

The FLRAA is the most costly upcoming program. AH-64 Apache 

procurement ends before FARA procurement begins, but H-60 Black Hawk 

and FLRAA procurement overlap.
6 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET may 2019

helicopters.11 The Army has also been investing in 

technologies to enable more fuel-efficient and powerful 

engines (the Improved Turbine Engine Program) for use 

in both current and future aircraft.

The Army envisions at least two aircraft emerging from 

the FVL program. The FLRAA would transport light 

forces and equipment farther and faster than the Black 

Hawks that it would replace.12 The FARA, an armed 

scout, would conduct reconnaissance, attack, and 

electronic warfare and might fly without human pilots 

on at least some missions.13 It would initially fulfill the 

armed reconnaissance missions previously carried out by 

the now-retired OH-58D Kiowa Warrior fleet, and the 

Army might eventually extend FARA procurement to 

replace the Apaches.CBO’s projections of FLRAA and 

FARA costs draw on insights from Army officials as well 

as on documentation that the Army provided.

Projected Procurement Schedules and Costs

For the Black Hawk and its replacement, the FLRAA, 

CBO’s projection reflects the following specifications: 

• Procurement of FLRAAs would start with 6 in 2030, 

increase to 30 per year starting in 2035, and remain 

steady at that rate thereafter.

• Procurement of UH-60V Black Hawks would 

continue through 2035 (so FLRAAs and UH-60Vs 

would be concurrently procured for six years, 2030 

to 2035).

• The average unit cost for procuring FLRAAs through 

2050 would be $53 million. 

For the Apache and the FARA, CBO’s projection 

includes the following specifications: 

• Procurement of FARAs would start with 6 in 2028, 

increase to 30 per year starting in 2032, and remain 

steady at that rate thereafter.

11. Possible approaches for FVL are discussed in “Whirlybirds Are 

Go,” Economist (August 25, 2018), http://tinyurl.com/y4xrrcya.

12. See Sydney J. Freedberg Jr., “Bell V-280 Flies 322 MPH: Army 

Secretary Praises Program,” Breaking Defense (January 24, 2019), 

https://tinyurl.com/yxgqnz4a. 

13. See Sydney J. Freedberg Jr., “Army Wants Revolutionary Scout 

Aircraft for $30 Million, Same As Apache E,” Breaking Defense

(October 3, 2018), https://tinyurl.com/y3mwjfdp.

• Procurement of AH-64E Apaches would continue 

through 2025, so no Apache or FARA procurement 

would occur in 2026 and 2027.

• The average unit cost for procuring FARAs through 

2050 would be $40 million.

Age of Fleets

With the projected procurement schedule, the average 

age of the combined Black Hawk/FLRAA fleet would 

rise considerably in the 2040s (see Figure 5). CBO 

projects that the average age of that fleet would plateau at about 15 years from the late 2020s through the 

late 2030s, but it would increase thereafter, reaching 

22.4 years by 2050 (and continuing to increase after 

2050 if the Army took no further steps to reduce the 

age of the fleet). By contrast, between the 1980s and the 

2000s, the average age of Army helicopters was 12 to 

18 years.14 In 2018, the oldest H-60s in operation were 

39 years old. Under the projected acquisition plan, the 

age of the oldest operating H-60s would be 35 years in 

2030 and 31 years in 2040, but it would be 37 years 

in 2050.

The average age of the Apache fleet was 7.8 years in 

2018. How plans to procure 30 FARAs per year would 

affect the combined Apache/FARA fleet depends on how 

many FARAs the Army added to augment its current 

armed reconnaissance capability and how many it added 

to replace retiring Apaches. If, for example, the Army 

opted to retire an Apache for every FARA it purchased, 

the average age of the combined AH-64/FARA fleet 

would be 10.6 years in 2030, 13.0 years in 2040, and 

12.8 years in 2050—average ages within the typical 

range for Army helicopters. The average ages would be 

higher if the Army added the initial FARAs to the force 

without retiring Apaches.

Uncertainties

Because the future national security environment and 

future Army budgets are unknown, projections out to 

2050 are quite uncertain. An aircraft’s retirement may be 

accelerated or postponed, or the aircraft may be retired 

and not replaced. Increased capabilities of new aircraft 

may also allow the Army to purchase fewer aircraft 

than it would under CBO’s assumption of one-for-one 

14. See Congressional Budget Office, The Long-Term Implications 

of Current Defense Plans: Detailed Update for Fiscal Year 2008 

(March 2008), Figures 3–7, www.cbo.gov/publication/19541.
may 2019 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET 7

replacement of existing aircraft. Moreover, new aircraft 

that do not replace existing aircraft may emerge, such as 

the Army’s remotely piloted MQ-1C Gray Eagle aircraft, 

which did not replace any existing aircraft. Two examples of uncertainties that pertain to the Army’s plans for 

procuring aircraft (and, therefore, to CBO’s projections) 

are how the FVL program will progress in the coming decades and, more immediately, how plans for the 

Chinook Block II modernization will change relative to 

the SAR on which CBO’s projections are based.

Long-range projections are nevertheless useful because 

they can assist the Congress, the Department of Defense, 

and the Army in setting appropriate budgets for procuring aircraft. They can also identify key future issues—

when many programs might need procurement appropriations at the same time, for example, or when retained 

aircraft would be growing old—and give decisionmakers 

enough time to address them. 

Uncertainty About the Future Vertical Lift Program

How the FVL program will progress is a source of considerable uncertainty in CBO’s projections, and it raises a 

variety of questions:

• What performance will the FVL variants achieve?

• How many FLRAAs and FARAs will be acquired, and 

how many FARAs will augment the force rather than 

replace Apaches?

• Will procurement quantities be sufficient to 

replace retiring aircraft, or will production need 

to be increased or supplemented with continued 

production of older designs?

• What will the unit costs of new aircraft be?

• Will there eventually be a Chinook FVL variant?

One example of such uncertainty is that the planned 

purchase rates for the FLRAA might be insufficient to 

keep up with the retirement of the Black Hawks. To 

address the Black Hawk/FLRAA age issue, the Army 

could adopt an alternative approach: At an annual 

procurement rate of 60 (rather than 30) FLRAAs per 

year starting in 2038, CBO estimates, the combined 

fleet’s average age would be 17.6 years in 2050 instead 

of the 22.4 years it would be if the Army procured 

Figure 5.

Estimated Average Ages of the AH-64 Apache/FARA, H-47 Chinook, 

and H-60 Black Hawk/FLRAA Fleets, 2018–2050

Years

AH-64

Apache/

FARA

H-60

Black Hawk/

FLRAA

H-47

Chinook

0

5

10

15

20

25

2015 2020 2025 2030 2035 2040 2045 2050

Source: Congressional Budget Office.

Age is measured in years since acquisition or remanufacture.

FARA = Future Attack Reconnaissance Aircraft; FLRAA = Future Long-Range Assault Aircraft.

The average age of the H-60 

Black Hawk/FLRAA fleet 

would increase considerably 

starting in the late 2030s 

if the Army procured 30 

FLRAAs each year and did not 

remanufacture older H-60s.
8 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET may 2019

30 FLRAAs per year. (Also, the oldest operating Black 

Hawk in 2050 would be 33 years old, not 37 years old.) 

However, doubling the annual procurement rate for the 

FLRAA would considerably increase the Army’s aviation 

procurement costs, although the costs would remain 

below the average budget for procuring Army aircraft 

over the 2010–2018 period (see Figure 6). A less costly 

alternative would be to continue procuring H-60 Black 

Hawks beyond 2035, although H-60s would be less 

capable helicopters than FLRAAs. Another option would 

be to retire more than one Black Hawk for each FLRAA 

procured. Doing so would reduce the size of the Army’s 

fleet and its operating costs.

Uncertainty About Chinook Modernization

CBO’s projection reflects the assumption that the Army 

will modernize its entire fleet of CH-47 and MH-47G 

heavy-lift helicopters by upgrading the aircraft to the 

improved Block II configuration, as indicated in the 

December 2017 CH-47 SAR. The Block II upgrades are 

intended to improve the Chinook’s performance (range, 

payload, and lifting capacity at higher altitudes and 

hotter ambient temperatures) and are expected to reduce 

operating costs. The upgrades will not, however, provide 

the dramatic increases in performance that the Army 

anticipates from the FVL technology it plans to incorporate into its FLRAA and FARA fleets. In particular, 

a Block II Chinook’s speed would be about 100 knots 

slower than what the Army hopes to achieve with the 

FLRAA. That difference could limit the Army’s ability to 

take advantage of the FLRAA’s speed in situations where 

heavy lift is also needed.15

In its budget request for the 2020 fiscal year, the Army 

reduced Chinook Block II purchases for 2020 through 

2024 from 72 to 34 aircraft, and it limited those 

upgrades to the much smaller MH-47G fleet used by 

special operations forces. Subsequent statements by 

Army officials described the service’s intent to defer or 

cancel Block II upgrades to the larger CH-47 fleet and 

redirect funding previously slated for those upgrades to 

higher-priority modernization efforts. The Army may 

revisit that decision, however, depending on the availability of future funding and on how FLRAA development 

15. The extent to which large speed differences would be a problem 

depends on the details of how the Army expects to operate. The 

Marine Corps, for example, operates fleets of widely differing 

speeds—the higher-speed MV-22 tiltrotor along with the slower 

CH-53, UH-1, and AH-1 conventional helicopters. 

Figure 6.

Projected Army Costs for Procuring Future Long-Range Assault Aircraft 

at Different Procurement Rates, 2019–2050

Billions of 2018 Dollars

Average Budget for Procuring Aircraft, 2010–2018

Average Budget for Procuring Aircraft,

2000–2009

0

3

6

9

2015 2020 2025 2030 2035 2040 2045 2050

Projected Costs

With 30 FLRAAs per

Year Starting in 2035

Projected Costs 

With 60 FLRAAs per 

Year Starting in 2038

Source: Congressional Budget Office.

FLRAA = Future Long-Range Assault Aircraft.

Doubling the procurement 

rate for the FLRAA from 

30 to 60 per year would 

considerably increase 

the projected costs of 

procuring Army aircraft but 

also reduce the age of the 

fleet.
may 2019 THE COST OF REPLACING TODAY’S ARMY AVIATION FLEET 9

progresses.16 (The relatively young age of the CH-47F 

fleet gives the Army time to wait and see how FVL technologies progress before committing to further upgrades 

to the much older CH-47 design.) Additionally, the 

Congress may decide to reverse the Block II cuts in 

authorization and appropriation legislation for 2020.

In CBO’s projection, canceling Block II upgrades to the 

CH-47F fleet would reduce the Army’s costs by about 

$700 million per year from the mid-2020s until after 

16. See Sydney J. Freedberg Jr. and Paul McLeary, “Will Army 

Uncancel CH-47F Chinook Upgrade? Sec. Esper and 

Gen. McConville,” Breaking Defense (April 16, 2019), 

https://tinyurl.com/yyzmzmp7.

2040. That reduction would be particularly large on a 

percentage basis in the 2020s before the increase in costs 

that, CBO projects, would occur in the 2030s when 

the Army began to purchase significant numbers of 

higher-cost FLRAAs and FARAs. Conversely, if the Army 

canceled the Chinook, it might need to begin developing 

an entirely new heavy-lift aircraft in the 2030s, when 

the oldest CH-47Fs would be approaching 25 years of 

age. An entirely new heavy-lift aircraft would certainly 

cost much more than Chinook Block II upgrades—and, 

probably, substantially more than the medium-lift 

FLRAA—and would lead to significantly higher costs 

for the Army in the late 2030s and 2040s than in CBO’s 

projections.

Appendix A

Appendix: Composition of the Army’s Current Fleet 

and CBO’s Estimate of Replacement Costs

The three tables in this appendix describe the 

Army’s current fleet and the analytical assessments the 

Congressional Budget Office used to project the costs of 

procuring aircraft.

Table A-1 shows the number of aircraft by category 

and by type of aircraft within each category, as well as 

information about the age of the fleet, as of April 15, 

2018. In aggregate, the aircraft ranged in age from 

just-delivered to 45 years old. Some types of aircraft 

ranged widely in age, including the Army’s largest 

fleets (H-60 Black Hawks, AH-64 Apaches, and 

H-47 Chinooks). Detailed descriptions of selected 

aircraft appear in Table A-2.

A fleet’s estimated total replacement cost is its fleet size 

from Table A-1 multiplied by its estimated replacement 

unit cost from Table A-3. CBO used that unit cost and 

the retirement schedule, also shown in Table A-3, to 

project the costs of procuring aircraft over time.
12 The Cost of Replacing Today’s Army Aviation Fleet May 2019

Table A-1.

Number and Age of Army Aircraft as of April 15, 2018

Age (Years)

Aircraft Number Minimum Average Maximum

Large Rotary-Wing 3,446 0 14.9 39

AH-64 Apache 744 0 7.8 29

H-47 Chinooka 423 0 9.7 32

H-60 Black Hawkb 2,279 0 18.1 39

Fixed-Wing 206 0 21.2 40

C-12 92 0 25.1 40

C-20 1 26 26.0 26

C-23 3 20 22.0 26

C-26 13 0 14.2 26

C-27 7 n.a. n.a. n.a.

C-37 3 13 15.3 18

CE-182 2 27 27.0 27

EO-5C 8 11 17.4 21

RC-12 30 18 23.9 37

T-6 12 3 3.0 3

T-34 1 1 1.0 1

UC-35 28 16 18.8 21

UV-18 6 2 20.3 40

Other Rotary-Wing 649 0 8.1 46

MH-6M 53 n.a. n.a. n.a.

OH-58 28 45 45.5 46

TH-67 155 n.a. n.a. n.a.

UH-1H 2 n.a. n.a. n.a.

UH-72 411 0 5.6 11

Entire Fleet 4,301 0 14.4 46

Source: Congressional Budget Office, using data from the U.S. Army.

The table does not include data for fixed-wing MQ-1C Gray Eagles, which were not available. Age is calculated as 2018 minus the fiscal year in which 

the aircraft was accepted into the fleet. 

n.a. = not available.

a. The H-47 Chinooks include both CH-47 and MH-47 helicopters. 

b. The H-60 Black Hawks include EH-60, HH-60, MH-60, and UH-60 helicopters. 
13

Table A-2.

Descriptions of Selected Army Aircraft

Aircraft Manufacturer Function Engine(s)

Operating 

Range

(Miles) Crew

Maximum 

Gross 

Weight 

(Pounds)

Maximum

Speed

(Miles per 

hour)

Large Rotary-Wing

AH-64 Apache

(E model)

Boeing Attack 2 turboshaft 

engines

300 1 pilot,

1 gunner

20,260 189

CH-47 Chinook Boeing Heavy cargo 

transport 

2 turboshaft 

engines

750 1 pilot, 1 copilot,

1 flight engineer

50,000 184

UH-60 Black Hawk

(M model)

Sikorsky Utility

transport 

2 turboshaft 

engines

360 2 pilots,

2 crew chiefs 

22,000 175

Fixed-Wing

C-12 Hurona Beechcraft Passenger

transport 

2 turboprop 

engines

1,990b 1 pilot,

1 copilot

12,500 363

C-20 Gulfstream Passenger

transport

2 turbofan 

engines

4,140 1 pilot, 1 copilot,

1 cabin attendant

72,000 528

C-37 Gulfstream Long-range

transport 

2 turbofan 

engines

6,770 2–3 pilots,

1 cabin attendant

85,000 574

MQ-1C Gray Eagle General Atomics Long-endurance, 

remotely piloted 

attack

1 heavy fuel 

engine

2,880 None 3,600 173

UC-35 Cessna Medium-range 

transport 

2 turbofan 

engines

2,000 1 pilot,

1 copilot

16,630 300

Other Rotary-Wing

OH-58 Kiowa Bell Training 1 turboshaft 

engine

290 1 pilot,

1 observer

4,500 149

UH-72 Lakota Airbus Light utility

transport

2 turboshaft 

engines

430 2 pilots 7,900 167

Sources: U.S. Army, Weapon Systems Handbook, 2016, www.army.mil/e2/c/downloads/431298.pdf (50 MB); Paul Jackson, ed., Jane’s All the World’s 

Aircraft: 2006–2007 (Jane’s Information, 2006).

a. The RC-12 resembles the C-12 but is used for reconnaissance.

b. Operating range with four passengers.

APPENDIX The Cost of Replacing Today’s Army Aviation Fleet
14 The Cost of Replacing Today’s Army Aviation Fleet May 2019

Table A-3.

CBO’s Estimates of Replacement Unit Costs and Retirement Ages for Each Aircraft Type

Aircraft

Replacement Unit Cost 

(Millions of 2018 dollars) Will Retire . . .

Large Rotary-Wing

AH-64 40 As replacements arrive.a New FARA procurement starts in 2028; 

steady-state procurement of 30 FARAs per year starts in 2032.

H-47 29 As replacements arrive.b Beyond 2043, CBO used the annual procurement 

quantities from 25 years earlier.

H-60 53 As replacements arrive.c New FLRAA procurement starts in 2030; 

steady-state procurement of 30 FLRAAs per year starts in 2035.

Fixed-Wing

C-12 6 At age 45, starting in 2023

C-20 n.a. [Army divesting C-20s; no replacement]

C-23 n.a. [Army divesting C-23s; no replacement]

C-26 12 At age 45, starting in 2037

C-27 n.a. [Army divesting C-27s; no replacement]

C-37 65 At age 45, starting in 2045

CE-182 0.5 At age 45, starting in 2036

EO-5C 10 At age 35, starting in 2032

MQ-1C 140d At age 20, starting in 2030

RC-12 14 At age 45, starting in 2023

T-6 6 At age 35, starting in 2050

T-34 3 At age 35, starting in 2052

UC-35 16 At age 35, starting in 2032

UV-18 10 At age 45, starting in 2023

Other Rotary-Wing

OH-58 n.a. [Army divesting OH-58s; no replacement]

TH-67 11 In 2021, to be replaced by UH-72s

UH-1H n.a. [Army divesting UH-1Hs; no replacement]

UH-72 8 At age 45, starting in 2052

Source: Congressional Budget Office.

CBO’s estimate reflects the assumption that funding for an aircraft must be appropriated two years before the aircraft arrives. The table does not 

include the MH-6C helicopter because age data were not available.

FARA = Future Attack Reconnaissance Aircraft; FLRAA = Future Long-Range Assault Aircraft; SAR = Selected Acquisition Report; n.a. = not applicable.

a. Per the AH-64E Apache Remanufacture SAR.

b. Per the CH-47F Modernized Cargo Helicopter (CH-47F Block II) SAR.

c. Per the UH-60M Black Hawk Helicopter SAR and the Army’s plans for UH-60V upgrades.

d. Cost per platoon.
List of Tables and Figures

Tables

A-1. Number and Age of Army Aircraft as of April 15, 2018 12

A-2. Descriptions of Selected Army Aircraft 13

A-3. CBO’s Estimates of Replacement Unit Costs and Retirement Ages for 

Each Aircraft Type 14

Figures

1. Age and Replacement Cost of the Army’s Fleet, 2018 2

2. The Army’s Budgets for Procuring Aircraft, 2000–2018 3

3. Projected Army Costs for Procuring Aircraft, 2019–2050 4

4. Projected Army Costs for Procuring Selected Aircraft, 2019–2050 5

5. Estimated Average Ages of the AH-64 Apache/FARA, H-47 Chinook, 

and H-60 Black Hawk/FLRAA Fleets, 2018–2050 7

6. Projected Army Costs for Procuring Future Long-Range Assault 

Aircraft at Different Procurement Rates, 2019–2050 8
About This Document

This report was prepared at the request of the Chairman and Ranking Member of the Senate 

Budget Committee. In keeping with CBO’s mandate to provide objective, impartial analysis, the 

report makes no recommendations.

Edward G. Keating, David Arthur, and Adebayo Adedeji prepared the report with guidance 

from David Mosher. Aurora Swanson provided helpful comments, as did Lisa Colabella of the 

RAND Corporation and J.J. Gertler of the Congressional Research Service. (The assistance of 

external reviewers implies no responsibility for the final product, which rests solely with CBO.) 

Sebastien Gay, John Kerman, David Newman, Chayim Rosito, and F. Matthew Woodward also 

assisted in the preparation of this report. Adam Talaber fact-checked the report. 

Jeffrey Kling, John Skeen, and Robert Sunshine reviewed this report; Rebecca Lanning edited 

it; and Robert Rebach prepared it for publication and drew the cover illustration. An electronic 

version is available on CBO’s website (www.cbo.gov/publication/55180).

CBO continually seeks feedback to make its work as useful as possible. Please send any comments 

to communications@cbo.gov.

Keith Hall

Director

May 2019