Symbols
A area
A1 intake high light area APR Augmented power rating
Ath throat area
AW wetted area
AR aspect ratio
a speed of sound, acceleration
¯a average acceleration at 0.7 V2
ac aerodynamic centre
a0_w wing zero lift line relative to fuselage reference line 𝛼ht angle of attack at the H-tail
b span
CR,CB root chord
CD drag coefficient
CDi induced drag coefficient CDp parasite drag coefficient
CDpmin minimum parasite drag coefficient
CDw wave drag coefficient
Cv specific heat at constant volume
CF overall skin friction coefficient, force coefficient Cf local skin friction coefficient, coefficient of friction
CL lift coefficient
Cl sectional lift coefficient, rolling moment coefficient CLi integrated design lift coefficient
CL𝛼 lift curve slope CL𝛽 side slip curve slope
Cm pitching moment coefficient
Cn yawing moment coefficient
Cp pressure coefficient, power coefficient, specific heat at constant pressure
CT thrust coefficient
CHT horizontal tail volume coefficient CVT vertical tail volume coefficient
Cxxxx cost with subscript identifying parts assembly C′xxxx cost heading for the type
CC combustion chamber
CG centre of gravity
k k
c chord
croot root chord
ctip tip chord
cp centre of pressure
D drag, diameter
Dskin skin friction drag
Dpress pressure drag
d diameter
E modulus of elasticity, stored energy E* mass (gravimetric) specific energy, EV* volumetric specific energy density
e Oswald’s factor
𝜀u deflected upwash angle 𝜀d deflected downwash angle
F force
f flat plate equivalent of drag, wing span fc ratio of speed of sound (altitude to sea level) Fca aft fuselage closure angle
Fcf front fuselage closure angle
FB body axis
FI inertia axis
FW wind axis
Fxxx component mass fraction, subscript identifies the item (Section 8.8) F/ma specific thrust
FR fineness ratio
G gearing ratio
g acceleration due to gravity
H height
h vertical distance, height
if incidence of the fuselage camber line relative to fuselage reference line it angle between H-tailMACHTand fuselage reference line
iw wing and fuselage setting angle.
J advance ratio
k constant, sometimes with subscript for each application
L length, lift
LFB nacelle fore-body length
LN nacelle length
LVT,lVT vertical tail arm LHT,lHT horizontal tail arm
L length
M mass, moment
Mf fuel mass
Mi component group mass, subscript identifies the item (Section 8.6) Mxxx component item mass, subscript identifies the item (Section 8.6)
m mass
̇
ma air mass flow rate
̇
mf fuel mass flow rate
̇
mp primary (hot) air mass flow rate (turbofan)
̇
ms secondary (cold) air mass flow rate (turbofan)
N revolution per minute, number of blades, normal force
k k
List of Symbols and Abbreviations li
Ne number of engine
n load factor
ng load factor times acceleration due to gravity P, p static pressure, power
P* mass (gravimetric) specific power Pbat electric power of the battery Pt,pt total pressure
p′ angular velocity about Y-axis pe exit plane static pressure p∞ atmospheric (ambient) pressure Q heat energy per of the system
q dynamic head, heat energy per unit mass q′ angular velocity aboutz-axis
R gas constant, reaction
Re Reynolds number
Recrit critical Reynolds number r radius, angular velocity
r′ angular velocity about thex-axis
S area, most of the time, with a subscript identifying the component SBs project side area of the fuselage
SH,SHT horizontal tail reference area Sn maximum cross sectional area SW wing reference area
SV,SVT vertical tail reference area sfc specific fuel consumption T temperature, thrust, time TC non dimensional thrust
TF non dimensional force (for torque) TSLS sea level static thrust at takeoff rating
T/W thrust loading
t/c thickness to chord ratio
tf turbofan
Ug vertical gust velocity U∞ free stream velocity
u local velocity along thex-axis
V free stream velocity
VA aircraft stall speed at limit load VB aircraft speed at upward gust VC aircraft maximum design speed VD aircraft maximum dive speed VS aircraft stall speed
Ve exit plane velocity (turbofan)
Vep primary (hot) exit plane velocity (turbofan) Ves secondary (cold) exit plane velocity (turbofan) W weight, width, rate of energy usage (per hour).
WA useful work done on aircraft
WE mechanical work produced by engine W/Sw wing loading
wu upwash deflected velocity wd downwash deflected velocity
k k x distance along thex-axis
y distance along they-axis
z vertical distance
Greek Symbols
α angle of attack
αeff effective angle of incidence
β CG angle with vertical at main wheel, blade pitch angle, side slip angle Γ dihedral angle, circulation
γ ratio of specific heat, fuselage clearance angle
Δ increment measure
δ boundary layer thickness
𝜀 downwash angle
𝜂t thermal efficiency
𝜂p propulsive efficiency
𝜂o overall efficiency
Λ wing sweep, subscript indicates the chord line.
λ taper ratio
μ friction coefficient, wing mass
ρ density
θ elevation angle, flight path angle, fuselage upsweep angle
π constant=3.14
σ atmospheric density ratio τ thickness parameter, torque
υ velocity
φ roll angle, bank angle ψ azimuth angle, yaw angle
ω angular velocity
Subscripts (in many cases the subscripts are spelled out and not listed here)
a aft
ave average
ep primary exit plane
es secondary exit plane
f front, fuselage
fb blockage factor for drag
fh drag factor for nacelle profile drag (propeller driven)
fus fuselage
HT horizontal tail
M middle
N, nac nacelle
o free stream condition
p primary (hot) flow
s stall, secondary (cold) flow
t, tot total
w wing
VT vertical tail
∞ free stream condition
k k
List of Symbols and Abbreviations liii
Abbreviations
AB After burner
ACAS Advanced Close Air Support ACT Activate Control Technology AEA Association of European Airlines AEW Airborne Early Warning
AF Activity Factor
AFM Aircraft Flight-track Monitoring
AGARD Advisory Group for Aerospace Research and Development AHM Aircraft Health Monitoring
AIAA American Institute for Aeronautics and Astronautics AJT Advanced Jet Trainer
AMPR Aeronautical Manufacturer’s Planning Report APM Aircraft Performance Monitoring
APU Auxiliary Power Unit ARINC Aircraft Radio Inc.
ASDA Acceleration Stop Distance Available
AST Air Staff Target
ATA Aircraft Transport Association ATF Advanced Tactical Support AVGAS Aviation GASoline (petrol) AVTUR Aviation Turbine Fuel
BAS Bombardier Aerospace–Shorts BFL Balanced Field Length
BLDC Brushless DC Motor
BMS Battery Management System
BOM Bill Of Material
BPR By-Pass Ratio
BRM Brake Release Mass
BWB Blended Wing Body
BVR Beyond Visual Range
CAD Computer Aided Design
CAE Computer Aided Engineering CAM Computer Aided Manufacture
CAS Close Air Support, Calibrated Air Speed CCV Control Configured Vehicle
CFD Computational Fluid Dynamics CFL Critical Field Length
CG Centre of Gravity
CV Control Volume
CWY Clearway
DCPR Design Controller’s Planning Report
DBT Design Build Team
DEP Distributed Electric Propulsion DFSS Design For Six Sigma
DFM/A Design for Manufacture/Assembly DOC Direct Operating Cost
DoD Department of Defence
DOD Depth of Discharge
k k DOT Department Of Transport
EAS Equivalent Air Speed
EASA European Aviation Safety Agency ECS Environment Control System EFIS Electronic Flight Information System
FS Factor of Safety
EPNL Effective Perceived Noise Level EPR Exhaust Pressure Ratio
ESHP Equivalent SHP
ETOPS Extended Twin Operations
EW Electronic Warfare
FAA Federal Aviation Administration
FADEC Full Authority Digital Electronic Control
FBW Fly-By-Wire
FEM Finite Element Method
FPS Foot/Pound System
HEA Hybrid Electric Aircraft HMD Helmet Mounted Display HOTAS Hands On Throttle And Stick
HR Hybrid Ratio
HUD Heads-Up Display
HP Horse Power, High Pressure H-tail Horizontal Tail
IATA International Air Transport Association
IC Internal Combustion
ICAO International Civil Aviation Organisation IOC Indirect Operational Cost
INCOSE International Council Of Systems Engineering IPPD Integrated Product and Process Development IATA International Air Transport Association ICAO International Civil Aviation Organization ISA International Standard Atmosphere JAA Joint Aviation Authority
JAR Joint Airworthiness Regulation JUCAS Joint Unmanned Combat Air System
KE Kinetic Energy
KEAS Knots Equivalent Air Speed L/D Lift-to-Drag (ratio)
LE Leading Edge
LF Load Factor
LFL Landing Field Length
LP Low Pressure
LCA Light Combat Aircraft
LCC Life Cycle Cost
LCN Load Classification Number LCR Lip Contraction Ratio LDA Landing Distance Available LERX Leading Edge EXtension (strake)
LOH Liquid Hydrogen
LPO Long Period Oscillation
k k
List of Symbols and Abbreviations lv
MAC Mean Aerodynamic Chord
MDA Multi-Disciplinary Analysis MDO Multi-Disciplinary Optimisation MEM (W) Manufacturer’s Empty Mass (Weight) MFD MultiFunctional Display
MFR Mass Flow Rate
MoD Ministry of Defence MOGAS MOtor GASoline (petrol)
MPM Manufacturer Process Management
MTM Maximum Taxi Mass
MTOM (W) Maximum Take-Off Mass (Weight)
NACA National Advisory Committee for Aeronautics NASA National Aeronautics and Space Administration NBAA National Business Aviation Association
NHA Negative High Angle Of Attack NIA Negative Intermediate Angle of attack
NiCad Nickel-Cadmium
NiMH Nickel-Metal Hybrid
NLA Negative Low Angle of attack
NRC Non-Recurring Cost
NTC (M) Normal Training Configuration (mass) OEM (W) Operating Empty Mass (Weight) OEMF Operating Empty Mass Fraction
PAX Passenger
PCN Pavement Classification Number
PCU Power Control Unit
PE Potential Energy
PHA Positive High Angle of attack PIA Positive Intermediate Angle of attack PLA Positive Low Angle of attack
PLM Product Life cycle Management PNdB Perceived Noise Decibel PNL Perceived Noise Level
PPR Product, Process and Resource
PV Photovoltaic
RAeS Royal Aeronautical Society
RAT Ram Air Turbine
RC Rate of Climb, Recurring Cost RCS Radar Cross-section Signature RD&D Research Design and Development
RDDMC Research Design, Development, Manufacture and Cost RDD&T Research Design, Development and Test
R&M Reliability and Maintainability
RF Range Factor
RFP Request for Proposal
RJ Regional Jet
RLD Required Landing Distance
RPM Revolution per Minute, Revenue Passenger Mile RPV Remotely Piloted Vehicle
RSA Runway Safety Area
k k SATS Small Aircraft Transportation System
SEP Specific Excess Power
sfc Specific Fuel Consumption
SHP Shaft Horse Power
SI System International
SPL Sound Pressure Level SPO Short Period Oscillation STOL Short TakeOff and Landing
SWY StopWaY
TAF Total Activity Factor TET Turbine Entry Temperature TGT Turbine Guide-vane Temperature TOFL Takeoff Field Length
TOC Total Operating Cost
TPT TurboProp Trainer
TQM Total Quality Management
TR Thrust Reverser
TTOM Typical TakeOff Mass (military) T&E Training and Evaluation
UAV Unmanned Air Vehicle
UAS Unmanned Aircraft System UCA Unmanned Combat Aircraft
UHBPR Ultra High BPR
ULD Unit Load Device
V-tail Vertical Tail
ZFM (W) Zero Fuel Mass (Weight)
k k
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