Design of UAV Systems
Objectives
Lesson objective - to discuss the fundamentals of
Life cycle cost
to include…
• What does it include?
• Why is it important?
Expectations • You will understand why life cycle cost is so
important and what kinds of issues it addresses
• At the end of this lesson, you should understand (1)
the fundamental issues and (2) how to make life
cycle cost estimates
© 2003 LM Corporation
Life Cycle Cost
13-1
Discussion subjects
Design of UAV Systems
• Review
• Parametric cost estimates
• Development
• Procurement
• UAV application
• Operations and support
• Manned aircraft
• UAV applications
© 2003 LM Corporation
Life Cycle Cost
13-2
Design of UAV Systems
Review - Life cycle cost
Development cost
• The cost of developing a system
• Considered a “non-recurring” cost
• Occurs only once (hopefully)
Procurement cost
• The cost to buy a system once it is developed
• Includes a lot of “recurring” cost
• Costs incurred every time a system is produced
Operations and support cost (Q&S)
• The cost to maintain and operate a system after
purchase
• Includes the cost of maintaining crew proficiency
• Excludes the cost of combat operations
Development + procurement + O&S  Life cycle cost
© 2003 LM Corporation
Life Cycle Cost
13-3
Design of UAV Systems
Review - cost issues
Development cost
• Customers want this to be as small as possible
• New systems are expensive
• Most of the cost is associated with risk
reduction, engineering and test
• Programs need “margin” to cover uncertainty
Procurement cost
• This cost is sensitive to procurement quantity
• Repetitive tasks become more efficient
• Also sensitive to the size and complexity
• Aircraft empty weight is considered a cost driver
Operations and support cost
• Most of the life cycle cost of an aircraft is the “O&S”
• O&S cost can be reduced by good up-front design
© 2003 LM Corporation
Life Cycle Cost
13-4
Design of UAV Systems
Review - LCC importance
Pre-concept design
• The product of this phase is a set of initial requirements
and cost, risk and schedule estimates
Key technical issues addressed during this phase include:
• Overall needs and objectives
• Concepts of operation
• Potential design concepts
• Initial cost and schedule
• Effectiveness estimates
• Analysis of alternatives
The technical work done during the pre-concept design
phase establishes the initial cost and schedule estimate
that the project will have to live with for the rest of its life
© 2003 LM Corporation
Life Cycle Cost
13-5
Cumulative Percent Of Life Cycle Cost
Design of UAV Systems
The cost driver - early decisions
100
95
85
Detailed
Design
Preliminary
Design
70
50
Concept
Design
Pre-concept
Design
10
Milestones
I
II
III
IOC
Out of Service
Source – Defense Systems Management College, 3 Dec. 1991
© 2003 LM Corporation
Life Cycle Cost
13-6
Next subject
Design of UAV Systems
• Review
• Parametric cost estimates
• Development
• Procurement
• UAV application
• Operations and support
• Manned aircraft
• UAV applications
© 2003 LM Corporation
Life Cycle Cost
13-7
Parametric cost estimates
Design of UAV Systems
• Parametric models or cost estimating relationships
(CERs) are used widely for aircraft cost estimating
- By industry for initial cost estimates
- By customers for proposal evaluation
• Used when little is known about the design
- But also used to check internal consistency of
detailed estimates
• Methodology updates occur periodically
- Need to capture technology benefits and costs
• Most recent updates focused on advanced structural
materials
- Composite airframe materials drive airframe cost
• Although no CERs yet exist for UAVs, they will exist
someday and we need to understand the approach
* (1) Advanced Airframe Structural Materials, a Primer and Cost Estimating
Methodology, RAND R-4016-AF, Resetar, Rogers and Hess, c1990
© 2003 LM Corporation
Life Cycle Cost
13-8
Design of UAV Systems
Material
Aluminum
Titanium
Steel
Composites
Other
Material utilization trends
USAF/AFRL data
RAND data
F-111 F-15 F-16 F-18 C-17 AV-8B B-2 F-18 F-22
(1967) (1972) (1976) (1978)
(E/F)
59% 52% 79%
5% 40% 2%
33% 5% 4%
2% 5%
1%
1% 10%
2%
48% 70% 47% 27%
14% 9% ?% 23%
15%
?
?
?
11% 8% 26% 37%
12% 13% 27% 13%
27%
23%
?
22%
13%
16%
39%
?
25%
20%
RAND Data - Advanced Airframe Structural Materials, a Primer and
Cost Estimating Methodology, RAND R-4016-AF,
Resetar, Rogers and Hess, c1990
AFRL Data – Evolution of U.S. Military Aircraft Structures
Technology, AIAA Journal of Aircraft,
Paul,Kelly,Venkaya,Hess, Jan-Feb 2003
© 2003 LM Corporation
Life Cycle Cost
13-9
Cost drivers
Design of UAV Systems
• CERs capture overall air vehicle cost drivers
1. Size including airframe and empty weight, area, etc.
2. Performance including speed, specific power, etc.
3. “Construction” including load factor, engine location,
area ratios, wing type, avionics weight ratio, etc.
4. Program including number of test aircraft, new vs.
existing engines, contractor experience, etc.
• Of these, a few emerge statistically as real drivers*
- Airframe unit weight (AUW)
- Empty weight (EW)
- Maximum speed (Vmax)
- Number of test aircraft (NTA)
- Airframe material type and composition
• Software should also be a driver (no data in 1990?)
* (2) RAND N-2283/2-AF, Aircraft Airframe Cost Estimating
Relationships : Fighters, December 1987
© 2003 LM Corporation
Life Cycle Cost
13-10
Design of UAV Systems
Cost categories and elements
• RAND defines CERs in two major overall cost
categories: non-recurring and recurring costs*
- Non-recurring (development) cost elements are:
- Non-recurring engineering hours (NRE)
- Non-recurring tooling hours (NRT)
- Development support cost (DS)
- Flight test cost(FT)
- Recurring (production) cost is normalized for 100 air
vehicles and made up of the following elements:
- Recurring engineering hours (RE100)
- Recurring tooling hours (RT100)
- Recurring manufacturing labor hours (RML100)
- Recurring manufacturing material cost (RMM100)
- Recurring quality assurance hours (RQA100)
* Their methodology does not include engines, avionics, armament, training,
support equipment and spares. These elements must be added.
© 2003 LM Corporation
Life Cycle Cost
13-11
Baseline CERs
Design of UAV Systems
• RAND starts with an aluminum baseline cost estimate
- Non-recurring cost elements
NRE(hrs) = 0.0168(EW^.747)(Vmax^.800)
(13.1)
NRT(hrs) = 0.01868(EW^.810)(Vmax^.579)
(13.2)
DS = 0.0563(EW^.630)(Vmax^1.30)
(13.3)
FT = 1.54(EW^.325)(Vmax^.823)(NTA^1.21) (13.4)
- Recurring cost elements
RE100(hrs) = 0.000306(EW^.880)(Vmax^1.12) (13.5)
RT100(hrs) = 0.00787(EW^.707)(Vmax^.813) (13.6)
RML100 (hrs)= 0.141(EW^.820)(Vmax^.484) (13.7)
RMM100 = 0.54(EW^.921)(Vmax^.621)
(13.8)
RQA100 (hrs-cargo acft) = 0.076*RML100
(13.9)
RQA100 (hrs-non-cargo) = 0.133*RML100
(13.10)
© 2003 LM Corporation
Life Cycle Cost
13-12
Typical application
Design of UAV Systems
• RAND example, hypothetical all-aluminum fighter
EW (lb)
27000
Vmax (kt)
1300
NTA
20
Structure (lb)
13000
Production quantity
100
• Typical labor rates
(1999 $/hr)*
Engineering
$86
Tooling
$88
Manufacturing
$73
Quality Assurance
$81
* From Raymer, page 588 - Inflation factors can be used
to adjust these to current year prices (also required for
material costs)
© 2003 LM Corporation
Life Cycle Cost
13-13
Baseline cost
Design of UAV Systems
• From equations 13.1 through 13.10
NRE(Khrs) = 10634
NRE($) = $914.5M
NRT(Khrs) = 4611
NRT($) = $405.7M
DS($) = $389.4M
FT($) = $577.6M
RE100(Khrs) = 7463
RE100($) = $642M
RT100(Khrs) = 3636
RT100($) = $320.0
RML100(Khrs) = 19502
RML100($) = $1423.7
RMM100 ($) = $559M
RQA100(Khrs) = 2594
RQA100($) = $210.0
Nonrecurring = $2,287M Recurring($) = $3,155M
Total program (from NR + R) = $5.44B
© 2003 LM Corporation
Life Cycle Cost
13-14
Other costs
Design of UAV Systems
• Engine cost
- Raymer’s cost discussion (Chapter 18) includes an
equation for engine procurement cost in 1999$
R(propul) = 2251*(0.043*Tmax + 243.25Mmax
+ 0.969*TiT -2228)
(13.11)
where
Tmax = Maximum thrust (lb)
Mmax = Maximum Mach
TiT = Turbine inlet temperature (degR)
≈ 2000 - 2500 degR
- For other propulsion cycles we will use $/lbm(engine)
• Avionics cost
- Raymer recommends a weight based approximation
of $3000-$6000 per pound ($1999)
- We will use $5000/lb for both avionics and payloads
© 2003 LM Corporation
Life Cycle Cost
13-15
Quantity effects
Design of UAV Systems
• RAND recurring cost methodology is based on
production quantities of 100 aircraft
- Other quantities are adjusted for the “learning curve”
- A term used to describe the efficiencies that result
from learning repetitive processes and tasks
- Learning curve effects are generally expressed by
exponential forms such as the following from RAND
Cost (Qn) = Cost(Q100)*(Qn/100)^exp (13.12)
where
exp(engineering hours) =
0.163
exp(tooling hours) =
0.263
exp(manufacturing hours) =
0.660
exp(manufacturing material) =
0.231
exp(tooling hours) =
0.714
exp(total program) =
0.356
© 2003 LM Corporation
Life Cycle Cost
13-16
Design of UAV Systems
Advanced material effects
• Advanced materials effects are applied to the
aluminum baseline as separate cost factors
• Effects of advanced materials vary by element
- Tooling (both nonrecurring and recurring) has twice
the sensitivity to material type as engineering
- Tooling focuses primarily on airframe structure
- Engineering hours are driven by a wider range of
design and manufacturing issues such as, design,
integration, test, evaluation, etc.
• Overall effects are captured by historical Structural
Cost Fractions (SCF) for airframe structure
Nonrecurring
Recurring
NRE - 45%
NRT - 87%
© 2003 LM Corporation
RE - 42%
RT - 82%
RML - 67%
Life Cycle Cost
RML - 67%
RMM - 58%
RQA - 69%
13-17
Complexity factors
Design of UAV Systems
• Used to capture labor hour and cost effects of
different design and manufacturing processes
- RAND uses complexity factors (CFs) to determine
material effects by structural cost element
Al
Al-li
Ti
Steel
GrExp
GrBi
GrTP
NRE NRT RE
RT
RML RMM RQA
1.0
1.1
1.1
1.1
1.4
1.5
1.7
1.0
1.1
1.9
1.4
2.2
2.3
2.4
1.0
1.1
1.6
1.2
1.8
2.1
1.8
© 2003 LM Corporation
1.0
1.2
1.4
1.1
1.6
1.7
2.0
1.0
1.1
1.4
1.1
1.9
2.1
2.9
Life Cycle Cost
1.0
2.7
2.8
0.7
4.9
5.5
6.5
1.0
1.1
1.6
1.4
2.4
2.5
2.6
13-18
Methodology
Design of UAV Systems
• Advanced material effects are applied to each cost
element
MWC (j) = SCF(j)*[CF(i,j)*SW(i)/ SF(I)]+[1- SCF(j)]
(13.13)
where
MWC(j) = Material weighted cost element j
SCF(j) = Structural cost fraction for cost element j
(chart 24-18)
CF(i,j) = Complexity factor (chart 24-19)
SW(i) = Structural weight by material type
• See RAND Report R-4016-AF, Advanced Airframe
Structural Materials, a Primer and Cost Estimating
Methodology, for more application information
© 2003 LM Corporation
Life Cycle Cost
13-19
UAV cost issues
Design of UAV Systems
• Unfortunately, there are no known UAV CERs
and no consistent UAV cost data bases. An
example:
- Total procurement cost projected by the Defense
Airborne Reconnaissance Organization (DARO)
for Predator in 1996 was $118M for 13 systems.
- In 1998 12 Predator systems were listed as
$512M or $42.7M per system
- The same document budgeted $23.9M for
one system for delivery in 1998
• These contradictions exist across a number of
UAV types and it is clear that a comprehensive
cost study is needed to resolve the issues
- Such a study is beyond the scope of this course
• We will take a simpler approach
© 2003 LM Corporation
Life Cycle Cost
13-20
UAV cost approach
Design of UAV Systems
• We will assume that manned aircraft CERs apply to
UAV air vehicles and propulsion
- Cursory checks show this not a bad assumption
• Global Hawk development cost ≈ $350M
- The RAND aluminum baseline development cost
CER for EW + payload = 11,100 lb, Vmax = 360 kts
and two flight test aircraft predicts a development
cost of $313M in $1999 (less engines and avionics)
- Avionics development costs are not available
• Global Hawk procurement cost goal = $10M
- The RAND aluminum baseline procurement cost
CER predicts a unit 20 development cost of $15.7M
- The customer acknowledged in 1998 that Global
Hawk unit cost would be about $13M
- Latest reports are that the airframe costs $16-20M
© 2003 LM Corporation
Life Cycle Cost
13-21
Design of UAV Systems
Other UAV system elements
• Little information is available on UAV control station
and communications development and no CERs
- Available data indicates Tactical Control Station (TCS)
development costs exceed $100M
• Development costs for the Global Hawk/Dark Star
common ground station (GCS) appear ≈ $250M
• We will assume, therefore, that control station
development (including communications) ≈ 70% of air
vehicle development cost
• Ground station procurement is harder to determine
- Predator ground and communications station costs
appear about equal at around $3M each
- Global Hawk/DarkStar initial GCS procurement ≈ $25M
each for 3 units. Latest reports = $45M
- We will assume control station procurement including
communications ≈ 1 air vehicle + payload procurement
© 2003 LM Corporation
Life Cycle Cost
13-22
Design of UAV Systems
Other system elements - cont’d
• We have no good information on UAV payload
development costs
- However, there are many payloads available off the
shelf and we will assume development cost is limited to
integration, which is covered under the air vehicle
• We also have no good information on UAV payload
procurement costs
- We will use Raymer’s assumed $5000 per pound
parametric until something better comes along
- This would imply that predator payload (450lb) costs
are about $2.25M, far more than airframe cost
- At a payload weight of 1900lb, Global Hawk payload
cost would be $9.5M, about equal to original airframe
estimate (recent USAF data cites payload at $11M)
• Despite the fact that some of these estimates are
guesses, we will use them until something better
comes along
- It is better to guess than to leave something out
© 2003 LM Corporation
Life Cycle Cost
13-23
Next subject
Design of UAV Systems
• Review
• Parametric cost estimates
• Development
• Procurement
• UAV application
• Operations and support
• Manned aircraft
• UAV applications
© 2003 LM Corporation
Life Cycle Cost
13-24
Manned aircraft data
Design of UAV Systems
O&S costs are driven by 2 factors
• 2/3 by manpower (pilots, operations, maintenance,
logistics and other personnel)
• 1/3 by flight hours - Flight hours (and numbers of
missions) drive maintenance and fuel consumption
• Average annual O&S ≈ 10% unit procurement cost
- Typical SE fighter ≈ $3M/yr or $9000/flight hour
Typical manned fighter O&S cost breakdown
- Direct personnel (pilots, maintenance, etc.) = 40-45%
- Pilots (10%), ops support (15%), maintenance (75%)
- Approximately 20-30 maintainers per aircraft
- Indirect (security, medical, facilities etc.) = 20-25%
- Fuel and spare parts = 25-35% (≈ $2K/FH for fighter)
- Other = 5-10%
- 1997 O&S data shows USAF average annual squadron
personnel costs at about $45K per person
© 2003 LM Corporation
Life Cycle Cost
13-25
Design of UAV Systems
Direct aircraft operating costs
This is the portion of the O&S cost that is directly
related to flight hours (fuel and spare parts)
- Direct operating costs are key figures of merit for
commercial operators
- Airlines typically quote direct operating costs in terms
of cost per seat mile
- Others including
the military use
cost per flight
hour ($/FH) and
it appears to
correlate with
empty weight
and speed
© 2003 LM Corporation
Life Cycle Cost
13-26
Design of UAV Systems
Other direct operating costs
• There is no information available on O&S cost for
payloads, communications equipment and ground
stations
- We can assume that the equipment is reliable but that
it undergoes regular upgrade and refurbishment at
least every 10 years
- We will assume, therefore, annual O&S cost to be
about 8% of initial procurement cost
• Once again, we are simply making an educated
guess but it is better to do so than to leave out an
important element of cost
- If our guesses are incorrect, we can improve them
when we get more data
- If we leave something out, there is no chance for
improvement
© 2003 LM Corporation
Life Cycle Cost
13-27
UAV data
Design of UAV Systems
Three O&S data points
• In 1997 DARO budgeted Hunter UAV operations and
support costs were at about $17.5 million for about
2000 flight hours or $8750/FH (almost the same as as
a typical manned fighter)
• In 1999 the VTUAV program established an O&S cost
goal of 25% less than Pioneer at $6500 per flight hour
• Published lifetime (10yr?) O&S cost for 11 Predator
systems (44 air vehicles) = $697M in $FY97
Other data
- UAV squadron manning data provides insight to adjust
manned aircraft O&S data for UAV applications
- A 4 air vehicle Predator squadron, for example,
deploys with 55 people, of which 30 are operators
and analysts and 24 are maintainers (13.75 total
people or 6 maintainers per aircraft)
© 2003 LM Corporation
Life Cycle Cost
13-28
Design of UAV Systems
UAV air vehicle application
The minimum data required are number of personnel
(maintenance and operators), flight hours (FH), direct
cost per FH, other direct cost and indirect personnel
• Predator for example has 13.75 persons per air vehicle.
At $45K per person per year (FY 97 est.), personnel
costs would be $620K/year per air vehicle
• Also assuming an indirect personnel cost ratio of 25%,
annual indirect costs would be $155K
• Assuming 1000 FH per year at $75/FH (chart 13-24 @
100 kts), air vehicle operating costs would be $75K
• Payload O&S is estimated at 8% procurement cost/year
= .08*(450lb*$5000/lb) = $180K
• Ground station plus comms is also estimated at 8% or
cost/year = 0.08*(≈$6M) = $480K
Estimated annual O&S cost for Predator, therefore,
would be about $1.5M per air vehicle
© 2003 LM Corporation
Life Cycle Cost
13-29
Comparison
Design of UAV Systems
From Defense Airborne Reconnaissance Office (DARO)
1996 Annual Report - Predator
11-12 System LCC (Base-year FY 1996 $M)
* RDT&E
* Production
* O&S, etc.
* Total
=
=
=
=
$ 213
$ 512
$ 697
$1,422
At 3%
inflation
= $761M
in FY99$
Our estimate for 11-12 systems (4448 vehicles) would be $660 - $720M
- O&S/production = 1.36 or 14% of production cost per year
(assuming a 10 year Life Cycle)
- Average manned fighter ratio = 11%
© 2003 LM Corporation
Life Cycle Cost
13-30
System cost - summary
Design of UAV Systems
Airframe
• Development - Equations 13.1 - 13.4
• Procurement - Equations 13.5 - 13.10
Propulsion (procurement) - Eq 13.11
Ground Station + communications
• Development - 70% air vehicle development
• Procurement ≈ 1 air vehicle + sensor payload
Payload (procurement) - $5000/lb
Operations and support
• Air vehicle & payload operators - estimate number
• Maintenance personnel - chart 12-30
• Other personnel - add 25%
• Air vehicle operating costs (inc. engine) - chart 24-27
• Ground station + communications - 8% procurement/yr
• Payload - 8% procurement/yr
© 2003 LM Corporation
Life Cycle Cost
13-31
Expectations
Design of UAV Systems
You should now understand the basic concept
design cost issues including
• Development
• Procurement
• Operations and support
© 2003 LM Corporation
Life Cycle Cost
13-32
Reading assignment
Design of UAV Systems
Raymer, Aircraft Design - A Conceptual Approach
Chapter 3 – Sizing from a conceptual sketch
•
•
•
•
•
Chapter 3.1 : Introduction
Chapter 3.2 : Takeoff weight buildup
Chapter 3.3 : Empty weight estimation
Chapter 3.4 : Fuel fraction estimation
Chapter 3.5 : Takeoff weight calculation*
Total : 25 pages
Note – Use Raymer as a reference book. It is not
necessary to memorize or derive any of the
equations. Read the sections over for general
understanding of the concepts.
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Life Cycle Cost
13-34
Intermission
Design of UAV Systems
© 2003 LM Corporation
Life Cycle Cost
13-34