jet transport equations
DESCRIPTION
Basic Equations for calculation of Jet Transport PerformanceTRANSCRIPT
Jet Transport
Performance Equations
Revised May 2009
© by Ralf M. Dittmer
Jet Transport Performance Equations Page 3
Table of Contents 1. CONVERSION FACTORS ......................................................................................................4 2. NOMENCLATURE ..................................................................................................................5 3. AERODYNAMICS...................................................................................................................6
3.1 Basics ................................................................................................................................6 3.2 Flow Relations near the Speed of Sound ...........................................................................6 3.3 Standard Atmosphere ........................................................................................................7 3.4 Airfoil Properties.................................................................................................................9 3.5 Force and Moment Coefficients .........................................................................................9 3.6 Generalized Lift and Drag ..................................................................................................9 3.7 Drag Analyses..................................................................................................................10 3.8 Airspeeds.........................................................................................................................10 3.9 Airspeed Conversions......................................................................................................10 3.10 Thrust Required .............................................................................................................12
4. JET ENGINE .........................................................................................................................14 4.1 Thrust Specific Fuel Consumption....................................................................................14 4.2 Net Thrust Equation .........................................................................................................14 4.3 Gross Thrust Equation .....................................................................................................14 4.4 Gross Thrust Function......................................................................................................14 4.5 Parameter Correction.......................................................................................................15
5. PERFORMANCE ..................................................................................................................16 5.1 Flight Capabilities.............................................................................................................16 5.2 Takeoff.............................................................................................................................17 5.3 Takeoff with Slush or Standing Water ..............................................................................20 5.4 Climb ...............................................................................................................................21 5.5 Enroute Climb ..................................................................................................................26 5.6 Cruise ..............................................................................................................................27 5.7 Economy Operation .........................................................................................................28 5.8 Descent ...........................................................................................................................29 5.9 Landing............................................................................................................................29
6. STABILITY AND CONTROL.................................................................................................31 6.1 Weight and Balance Control.............................................................................................31 6.2 Moments..........................................................................................................................32 6.3 Static Longitudinal Stability ..............................................................................................32
APPENDIX................................................................................................................................33 Table of A Values for Reynolds Number Correction ...............................................................33 Table of Primary Geometry Parameters for Boeing Airplanes ................................................34
Jet Transport Performance Equations Page 4
1. CONVERSION FACTORS Multiply By To obtain Mass Kilogram 2.2046 Pounds Pound 0.04536 Kilograms Length Feet 0.3048 Meters Feet 12 Inches Yard 3 Feet Meter 3.281 Feet Nautical Mile 6076 Feet Area Square Feet 0.0929 Square Meters Square Meter 10.76 Square Feet Volume US Gallon 3.785 Liters Liter 0.2642 US Gallons Speed Knot 1.689 Feet/sec Knot 101.34 Feet/sec Acceleration m/sec² 3.28084 ft/sec² Power Horse Power (HP) 550 ft-lbs/sec Pressure Lbs/in² 144 Lbs/ft² Temperature
4040C59F 4040F
95C
459.67FR 273.15CK
Jet Transport Performance Equations Page 5
2. NOMENCLATURE a = acceleration, ft/sec² A = cross-sectional area, ft² A = Reynolds Number drag constant a = lift curve slope, per degree a = speed of sound, ft/sec or knots a = standard day temperature lapse rate AR = aspect ratio Aj = jet nozzle area, ft² b = wing span, ft c = chord of wing, ft CAS = Calibrated Airspeed, knots CD = drag coefficient CDI = induced drag coefficient CDM = compressible drag coefficient CDp = parasite drag coefficient Cg = gross thrust coefficient CL = lift coefficient CM = moment coefficient CN = yawing moment coefficient Cp = pressure coefficient cr = root chord, ft ct = tip chord, ft D = drag, lbs e = Oswalds’ efficency factor EAS = Equivalent Airspeed, knots FG = gross thrust, lbs FN = net thrust, lbs le = engine arm, ft lt = tail arm, ft M = Mach Number MAC = Mean Aerodynamic Chord, ft n = load factor p = pressure, lbs/ft² q = dynamic pressure, lbs/ft² R = radius of turn, ft R/C = rate of climb, ft/min R/D = rate of descent, ft/min Re = Reynolds Number S = distance, ft S = wing area, ft² T = absolute temperature, K or °R T = thrust, lbs t = time, sec TAS = True Airspeed, knots V = velocity, ft/sec or knots VG = ground Speed, knots Vj = nozzle exhaust velocity, ft/sec
W = weight, lbs WA = airflow, lbs/sec WF = fuel flow, lbs/hr or lbs/sec = angel of attack, degree = bank angel, degree = gradient = ratio of specific heat = spindown factor
Jet Transport Performance Equations Page 6
3. AERODYNAMICS
3.1 Basics Continuity Equation constAVρ [3.1.1] Bernoulli Equation Incompressible:
222
211 ρV
21pρV
21p [3.1.2]
Compressible:
2
Vρp
12V
ρp
1
22
2
2
2
221
1
1
1
1
[3.1.3]
Dynamic (Impact) Pressure
2ρV21q with V in knots:
295.375σVq
2TAS [3.1.4]
3.2 Flow Relations near the Speed of Sound Mach Number
aVM [3.2.1]
Total Temperature Ratio 2
t 0.2M1θθ [3.2.2] Total Pressure Ratio
3.52t 0.2M1δδ [3.2.3]
Total Density Ratio
2.52t 0.2M1ρρ [3.2.4]
Jet Transport Performance Equations Page 7
3.3 Standard Atmosphere Temperature Below 36089 feet: pSTD 0.0019812h288.15T [3.3.1]
p6
0
STD h106.8755861T
Tθ [3.3.2]
Above 36089 feet: TSTD = 216.65 K = 0.7519 Pressure Ratio Below 36089 feet:
5.25588p
6
0
STD h106.8755861p
pδ [3.3.3]
Above 36089 feet:
2080636089h
0.2234eδ [3.3.4] Density Ratio
θδ
ρρσ
0
STD [3.3.5]
Tapeline Altitude
geo
geotape hr
rhh
[3.3.6]
r = 20855531 ft (average radius of the earth) Speed of Sound θ661.4786a [3.3.7a]
RT29.04a [3.3.7b]
Jet Transport Performance Equations Page 8
STANDARD ATMOSPHERE TABLE
hp OAT a/a0 atmospheric pressure feet °F °C = T/T0 in.Hg lb/ft² mb = p/p0 = /0
0 59.0 15.0 1.0000 1.0000 29.921 2116.2 1013.2 1.0000 1.0000
1000 55.5 13.0 0.9932 0.9966 28.868 2041.7 977.5 0.9648 0.9714 2000 51.9 11.1 0.9863 0.9931 27.830 1968.3 942.4 0.9301 0.9430 3000 48.3 9.1 0.9794 0.9896 26.821 1897.0 908.2 0.8964 0.9153 4000 44.8 7.1 0.9726 0.9862 25.855 1828.6 875.5 0.8641 0.8884 5000 41.2 5.1 0.9657 0.9827 24.906 1761.5 843.4 0.8324 0.8620
6000 37.6 3.1 0.9588 0.9792 23.985 1696.3 812.2 0.8016 0.8360 7000 34.1 1.1 0.9519 0.9757 23.093 1633.3 782.0 0.7718 0.8108 8000 30.5 -0.8 0.9451 0.9722 22.237 1572.8 753.0 0.7432 0.7864 9000 26.9 -2.8 0.9382 0.9686 21.397 1513.3 724.5 0.7151 0.7622
10000 23.4 -4.8 0.9313 0.9650 20.583 1455.7 697.0 0.6879 0.7386
11000 19.8 -6.8 0.9244 0.9615 19.796 1400.1 670.3 0.6616 0.7157 12000 16.2 -8.8 0.9176 0.9579 19.042 1346.7 644.8 0.6364 0.6935 13000 12.7 -10.7 0.9107 0.9543 18.300 1294.3 619.7 0.6116 0.6716 14000 9.1 -12.7 0.9038 0.9507 17.585 1243.7 595.5 0.5877 0.6503 15000 5.5 -14.7 0.8969 0.9470 16.890 1194.6 572.0 0.5645 0.6294
16000 2.0 -16.7 0.8900 0.9434 16.217 1147.0 549.2 0.5420 0.6090 17000 -1.6 -18.7 0.8832 0.9398 15.577 1101.7 527.5 0.5206 0.5894 18000 -5.2 -20.6 0.8763 0.9361 14.949 1057.3 506.2 0.4996 0.5701 19000 -8.7 -22.6 0.8694 0.9324 14.338 1014.1 485.5 0.4792 0.5512 20000 -12.3 -24.6 0.8625 0.9287 13.752 972.6 465.7 0.4596 0.5329
21000 -15.9 -26.6 0.8557 0.9250 13.189 932.8 446.6 0.4408 0.5151 22000 -19.4 -28.6 0.8488 0.9213 12.642 894.1 428.1 0.4225 0.4978 23000 -23.0 -30.6 0.8419 0.9176 12.109 856.4 410.0 0.4047 0.4807 24000 -26.6 -32.5 0.8350 0.9138 11.597 820.2 392.7 0.3876 0.4642 25000 -30.1 -34.5 0.8282 0.9101 11.110 785.7 376.2 0.3713 0.4483
26000 -33.7 -36.5 0.8213 0.9063 10.631 751.9 360.0 0.3553 0.4326 27000 -37.3 -38.5 0.8144 0.9024 10.170 719.3 344.4 0.3399 0.4174 28000 -40.8 -40.5 0.8075 0.8986 9.727 688.0 329.4 0.3251 0.4026 29000 -44.4 -42.4 0.8007 0.8948 9.302 657.9 315.0 0.3109 0.3883 30000 -48.0 -44.4 0.7938 0.8910 8.890 628.7 301.0 0.2971 0.3743
31000 -51.5 -46.4 0.7869 0.8871 8.492 600.6 287.5 0.2838 0.3607 32000 -55.1 -48.4 0.7800 0.8832 8.106 573.3 274.5 0.2709 0.3473 33000 -58.7 -50.4 0.7732 0.8793 7.741 547.5 262.1 0.2587 0.3346 34000 -62.2 -52.3 0.7663 0.8754 7.385 522.3 250.1 0.2468 0.3221 35000 -65.8 -54.3 0.7594 0.8714 7.043 498.2 238.5 0.2354 0.3100
36000 -69.4 -56.3 0.7525 0.8675 6.714 474.9 227.4 0.2244 0.2982 36089 -69.7 -56.5 0.7519 0.8671 6.684 472.7 226.3 0.2234 0.2971 37000 -69.7 -56.5 0.7519 0.8671 6.397 452.4 216.6 0.2138 0.2843 38000 -69.7 -56.5 0.7519 0.8671 6.098 431.3 206.5 0.2038 0.2710 39000 -69.7 -56.5 0.7519 0.8671 5.811 411.0 196.8 0.1942 0.2583 40000 -69.7 -56.5 0.7519 0.8671 5.538 391.7 187.5 0.1851 0.2462
41000 -69.7 -56.5 0.7519 0.8671 5.278 373.3 178.7 0.1764 0.2346 42000 -69.7 -56.5 0.7519 0.8671 5.030 355.7 170.3 0.1681 0.2236 43000 -69.7 -56.5 0.7519 0.8671 4.793 339.0 162.3 0.1602 0.2131 44000 -69.7 -56.5 0.7519 0.8671 4.569 323.1 154.7 0.1527 0.2031 45000 -69.7 -56.5 0.7519 0.8671 4.354 307.9 147.4 0.1455 0.1935
T0 = 288.15 K = 15°C = 59°F = 518.67°R p0 = 29.92 inHg = 1013.25 mbar = 14.7 psi 0 = 0.002377 slug/ft³ a0 = 1116.45 ft/sec = 661.4786 knots
Jet Transport Performance Equations Page 9
3.4 Airfoil Properties Taper Ratio
r
t
ccλ [3.4.1]
Aspect Ratio
SbAR
2
[3.4.2]
Mean Aerodynamic Chord (MAC)
Sdbc
MAC2 [3.4.3]
3.5 Force and Moment Coefficients Lift Force
δS1481.351M
LiftSσVLift295.369C 22
TASL [3.5.1]
Drag Force
δS1481.351M
DragSσVDrag295.369C 22
TASD [3.5.2]
Moment
δSc1481.351M
MomentScσV
Moment295.369C 22TAS
M [3.5.3]
3.6 Generalized Lift and Drag Lift
SM1481.351CδL 2
L [3.6.1]
Drag
SM1481.351CδD 2
D [3.6.2]
Jet Transport Performance Equations Page 10
3.7 Drag Analyses Total Drag Coefficient
DM
2L
DPDSD0D CπARe
CCCCC [3.7.1]
Induced Drag Coefficient
πARe
CC2L
Di [3.7.2]
Reynolds Number Effect on Drag DREDNOMD ΔCCC [3.7.3a]
nominal2
actual2
4-DRE
θ0.38312θδθ
0.38312θδ
logA10ΔC [3.7.3b]
3.8 Airspeeds Calibrated Airspeed (CAS) PIASCAS ΔVVV [3.8.1] Equivalent Airspeed ( EAS ) CCASEAS ΔVVV [3.8.2] True Airspeed ( TAS )
σ
VV EASTAS [3.8.3]
Mach Number
a
VM TAS [3.8.4]
3.9 Airspeed Conversions CAS to EAS (Requires Knowing )
111
661.4786CAS.21
δ1δ1479.1EAS
3.51
3.52
[3.9.1]
Jet Transport Performance Equations Page 11
EAS to CAS (Requires Knowing )
1111479.1EAS
δ11δ1479.1CAS
3.51
3.52
[3.9.2]
CAS to TAS (Requires Knowing and )
111
661.4786CAS.21
δ1θ1479.1TAS
3.51
3.52
[3.9.3]
TAS to CAS (Requires Knowing and )
1111479.1TAS
θ11δ1479.1CAS
3.51
3.52
[3.9.4]
EAS to TAS (Requires Knowing , or and )
δθEAS
σEASTAS [3.9.5]
TAS to EAS (Requires Knowing , or and )
θδTASσTASEAS [3.9.6]
Jet Transport Performance Equations Page 12
3.10 Thrust Required
Liftcoefficient
2L 1481.351SMδW
C [3.10.1]
Thrust Required
SM1481.351CδT 2
D [3.10.2]
Jet Transport Performance Equations Page 13
COMPRESSIBILITY CORRECTION VC
Jet Transport Performance Equations Page 14
4. JET ENGINE
4.1 Thrust Specific Fuel Consumption
N
F
FWTSFC [4.1.1]
4.2 Net Thrust Equation Turbojet
aA
GambjjjF
ajA
N Vg
WFppAVg
WVVg
WF [4.2.1]
Turbofan (Common Exhaust)
ambjjjF
ajAp
ajAf
N ppAVg
WVVg
WVV
gWF [4.2.2]
Turbofan
ambjjjF
ajAp
afAf
N ppAVg
WVVg
WVV
gWF [4.2.3]
4.3 Gross Thrust Equation Turbojet
coldj
hotjgjambG A
ACAψpF [4.3.1]
4.4 Gross Thrust Function Unchocked Nozzle
1pp
12ψ
1
amb
tNγγ
γγ
[4.4.1]
Chocked Nozzle
11
2pp2ψ
11
amb
tN
γ
γ [4.4.2]
By-Pass engine with common exhaust
111pp
12
pppp
ψ
1
sMN
tMN
sMN
tMN
amb
tMN
γγ
γγ
with: 1.8
.8ppp t7Ft7tMN
[4.4.3]
Jet Transport Performance Equations Page 15
4.5 Parameter Correction Thrust
δFCF N
N [4.5.1]
Speed
Xt
11 θ
NCN [4.5.2]
Fuel Flow
Xtt
FF θδ
WCW [4.5.3]
Airflow
δθWCW
XA
A [4.5.4]
Gas Temperature
XθEGTCEGT [4.5.5]
Jet Transport Performance Equations Page 16
5. PERFORMANCE
5.1 Flight Capabilities Load Factor
cosφ
1WLn [5.1.1]
Stall Speed FAR-Stall
S
295.375V
WC2eMin
LsFAR
[5.1.2]
1g-Stall
S
295.375V
nWC2eMaxL
gLs1
[5.1.3]
CG Correction
AftFwd
tLsRefCGLsFwdCG cgcg
lMAC1CC [5.1.4]
Buffet Altitude
LBuffet
2SC1481.351MnWδ [5.1.5]
Radius of Turn
tanφg
2.852721VR2TAS [5.1.6]
Jet Transport Performance Equations Page 17
5.2 Takeoff Acceleration and Minimum Rotation Speed
φWSqµCCµWTWga LD [5.2.1a]
GMMLM
-TGM
R
µZXXXXCCcgSρ
TZµZ2XW2Vmin
[5.2.1b]
Segment A (All engine acceleration distance to V1)
1
W
V
V
WGA dV
aVVS [5.2.2]
Segment A1 (One engine inoperative acceleration distance from VEF to V1)
1
EF
V
V
WGA1 dV
aVVS [5.2.3]
with
φW
295.375σVSµCCµWηT
Wga
21
LD [5.2.4]
Engine Failure Speed (VEF)
φW
295.375σV
WSµCCµ
WTη
1.6878ΔtgVV
21
LDV
1EF1
[5.2.5]
Jet Transport Performance Equations Page 18
Segment B (One engine inoperative acceleration distance from V1 to VLOF) GB2GB1GB SSS [5.2.6] with:
R
1
V
V
WGB1 dV
aVVS where: φWSqµCCµWηT
Wga LD
ΔtV2VV1.6878S W
LOFRGB2
where:
2LOF2R toVVtoVV ttΔt
Segment C (One engine inoperative flare distance to V2 at 35 feet)
2LOFtoVVW
2LOFC tV
2VV1.6878S
[5.2.7]
Jet Transport Performance Equations Page 19
Segment D (Distance traveled from V1 to the establishment of the full braking configuration)
B
1
V
V
WGD dV
aVVS [5.2.8]
φW
295.375σVSµCCWµηT
Wga
21
LDavg
Brake Application Speed (VB)
φW
295.375σV
WSµCCµ
WTη
1.6878ΔtgVV
21
LDavgV
1B1
[5.2.9]
Average Friction Coefficient (µavg)
BR
FMSP
FTBASPBavg µµ
2ttt
µµ
[5.2.10a]
for 707 and 737
BR
FMSP
FTSPBABavg µµ
2ttt
µµ
[5.2.10b]
where: µB Braking coefficient µR Rolling coefficient of friction tBA Flight test time between engine failure recognition and brake application, [sec] tSP Flight test time between engine failure recognition and spoiler application, [sec] tSP FM Flight Manual time between engine failure recognition and spoiler action, [sec] Segment E (Stopping distance from VB to VW)
W
B
V
V
WGE dV
aVVS [5.2.11]
Balanced Field Length GEGDCGB SSSS [5.2.12] Distance and time to VR (simplified method)
Rat0.707V
2WR
G 2aVV2.849S
[5.2.13]
Jet Transport Performance Equations Page 20
Rat0.6V
WRG 2a
VV1.6878t [5.2.14]
Wind Correction
71
2
1
2
1
HeightHeight
WindWind
[5.2.15]
Airplane Height2 Height1 Wind1/Wind2
707 50 feet 10 feet .795 727 50 feet 10 feet .795 737 50 feet 8 feet .770
737-300 32.8 feet 8 feet .8174 747 50 feet 16 feet .850 757 32.8 feet 12.5 feet .8713 767 32.8 feet 13.5 feet .881
5.3 Takeoff with Slush or Standing Water Slush Force
TireslushD2GS ACσV
21F [5.3.1]
= Slush density, 1.65 slugs/ft³ Equal to specific gravity of 0.85 VG = Ground Speed – Feet per second CDslush = Slush drag coefficient for airplane’s specific gear arrangement ATire = Reference area for slush force calculation Hydroplaning Speed
Gravityspecific
PressureTire8.63VHP [5.3.2a]
Tire Pressure must be in psi newer airplane’s: PressureTire8.63VHP [5.3.2b] Slush Force Including Hydroplaning
HPTireslushD2GS fACσV
21F
[5.3.3]
with fHP above VHP:
Jet Transport Performance Equations Page 21
1.5V
2.5V
HP
GHPHP
HP
G
0.6VV1.6Vf
5.4 Climb
Rate of Climb
dhdV
gV1
VW
DT
101.27R/C
[5.4.1]
Climb Gradient
dhdV
gV1
CC
WT
L
D
[5.4.2]
Geometric Gradient
G
geometric VR/C
γ with: WTASG VcosVV γ [5.4.3]
Climb Trade
ga
ResidualTotal γγ [5.4.4]
Jet Transport Performance Equations Page 22
Turning
dhdV
gV1
WΔDDT φbankZero
φ
γ [5.4.5a]
dhdV
gV1
CCC
Δ bankZeroL
bankZeroDDφ
φ
γ [5.4.5b]
FAR Minimum Climb Gradient Requirements
Segment 1 2 3 Final Number of
engines Minimum Gross Gradient [%] 2 positive 2.4 1.2 3 0.3 2.7 1.5 4 0.5 3.0 1.7
Net Gradient Reduction 2 Engines: 0.8% 3 Engines: 0.9% 4 Engines: 1.0% FAR Takeoff Path
Jet Transport Performance Equations Page 23
Jet Transport Performance Equations Page 24
Acceleration Factor dhdV
gV1
Temperature Constant Below Above Speed Tropopause Tropopause M 20.133184M1 0 Standard VC 0.190263φ0.7M1 2 φ0.7M1 2 VE 20.566816M1 20.7M1 M 20.133184M1 0
Non Standard VC
TT0.190263φ0.7M1 std2 φ0.7M1 2
VE
TT0.19026310.7M1 std2 20.7M1
2.522
3.52
0.2M10.7M10.2M1φ
One Engine Inoperative Climb Yawing Moment Coefficient
blΔC
δSb1481.351MlF
C eWMD2
eOPERATINGNN [5.4.6]
Engine Inoperative Drag ControlDWMDDOutEngD ΔCΔCCC [5.4.7]
Jet Transport Performance Equations Page 25
ACCELERATION FACTOR
Jet Transport Performance Equations Page 26
5.5 Enroute Climb Time At ISA
average
12
R/ChhΔt
[5.5.1a]
At Non ISA
average
stdp1p2
R/CTThh
Δt
[5.5.1b]
Distance
60
ΔtVΔnam average [5.5.2]
Fuel
60
ΔtWΔW averageF
F [5.5.3]
Jet Transport Performance Equations Page 27
5.6 Cruise Still Air Distance
WTAS
TAS
VVVnmnam
[5.6.1]
Fuel Mileage
F
TAS
WV
lbsnam
[5.6.2]
Range
2
1
XWWln
DLM
θTSFC
θ661.4786R [5.6.3]
Integrated Range Range
ΔWlbs
namΔRaverage
[5.6.4a]
ΣΔRR [5.6.4b] Time
averageVΔRΔt [5.6.5a]
ΣΔtt [5.6.5b] Non Standard Temperature Effects when maintaining a constant Mach Number Speed
std
std TTTASTAS [5.6.6a]
Fuel Flow, where Fuel Flow is a function of
X
stdStdFF T
TWW
[5.6.6b]
Specific Range, where Fuel Flow is a function of
X0.5
stdstd TT
lbsnam
lbsnam
[5.6.6c]
Jet Transport Performance Equations Page 28
5.7 Economy Operation Cost Index
cents/lb
$/hr100C
CCostFuelCostTimeCI
F
T [5.7.1]
Total Trip Cost FCTCC FT [5.7.2] Economy Cruise Speed Cost Index
dMlbs
namd
lbsnam
Mθ661.4786CI 2
2
[5.7.3]
Economy Cruise Cost Function
G
F
VW100CIECCF
[5.7.4]
Jet Transport Performance Equations Page 29
5.8 Descent
Rate of Descent
dhdV
gV1
VW
TD
101.27R/D
[5.8.1]
Descent Time, Fuel and Distance Refer to Enroute Climb Geometric Gradient
G
geometric VR/D
γ with: WTASG VcosVV γ [5.8.2]
5.9 Landing
Jet Transport Performance Equations Page 30
Approach Speed FARSg1SREFAPP 1.30Vor1.23VVV [5.9.1] Distance from 50 feet to Touchdown
airWTDAPP
A ΔtV2
VV1.6878S
[5.9.2a]
L0
L
D
L
DA C1ngσρ
WT
CC
SW
WT
CC
50S
[5.9.2b]
Distance from Touchdown Speed to full braking
TRANWBTD
TRAN ΔtV2
VV1.6878S
[5.9.3]
Distance from full Braking Speed to full stop
W
B
V
V
WB dV
aVVS [5.9.4]
with: φWSqµCCWµTWga LDB
Landing Distance BTRANAL SSSS [5.9.5] FAR Landing Field Length LFARL 1.667SS [5.9.6] Wet FAR Landing Field Length FARLWetFARL 1.15SS [5.9.7]
Jet Transport Performance Equations Page 31
6. STABILITY AND CONTROL
6.1 Weight and Balance Control
100
MACLEMACarmCG%MAC
[6.1.1]
Index Units according AHM560
K
CRef.StaarmWI
[6.1.2]
100MAC
LEMACRef.StaW
CKI
%MAC
[6.1.3]
W = Weight actual arm = Station horizontal distance in inches or meters from datum
to the location of the weight. Ref. Sta = Reference station/axis. Selected station around which all index values are calculated. K = Constant used as a plus value to avoide negative index figures. C = Constant used as a denominator to convert moment
values into index values. I = Index value corresponding to respective weight. MAC = Length of Mean Aerodynamic Chord in inches or meters. LEMAC = Horizontal distance in inches or meters from datum to location of the Leading Edge of the MAC.
Jet Transport Performance Equations Page 32
6.2 Moments Pitching Moment Yawing Moment Rolling Moment
qScCM m [6.2.1] qSbCN N [6.2.2] qSbCl l [6.2.3]
6.3 Static Longitudinal Stability
Pitching Moment Coefficient
VηCCCcSqZT
cXCC tLtmfusm.25c
TLmCG [6.3.1]
with:
qqη t
t and Sc
XSV tt
Slope
VηdCdC
dCdC
dCdC
cX
dCdC
tL
Lt
L
mwb
L
mE
L
mCG [6.3.2]
with:
mfusm.25cmwb CCC qScTZC T
mE
αddε1Vη
aa
dCdC
dCdC.25
cX
dCdC
tw
t
L
mwb
L
mECG
L
mCG
Jet Transport Performance Equations Page 33
APPENDIX
Table of A Values for Reynolds Number Correction single-aisle models A twin-aisle models A 737-300 -59.57 747-200 -39.826 737-400 -63.99 747-300 -39.826 737-500 -59.58 747-400 -43.60 737-600 -59.98 767-200 -42.222 737-700 -59.623 767-300 -43.65 737-800 -63.99 767-400 -45.23 737-900 -64.80 757-200 -49.434 777-200 -45.29 757-300 -56.24 777-300 -46.89
Jet Transport Performance Equations Page 34
Table of Primary Geometry Parameters for Boeing Airplanes Many of the equations require airplane geometry parameters such as the reference wing area Sref, reference wingspan bref and the engine moment arm. Those are contained in the following table. Additionally, parameters MAC and LEMAC are used in weight and balance calculations and the wing angle of incidence is used in body attitude calculations. Model Sref bref MAC LEMAC eng mom arm wing (ft²) (ft) (in) (in) (ft) incid -------------------------------------------------------------------------------------------------------------------------- 707-100, -100B 2433 130.83 241.88 786.2 27.17 (inbd) 2°
46.08 (outbd) 707-200 2433 130.83 241.88 786.2 27.17 (inbd) 2°
46.08 (outbd) 707-300/B/Badv, C 2892 142.42 272.29 762.97 33.0 (inbd) 2°
52.0 (outbd) 707-400 2892 142.42 272.29 762.97 33.0 (inbd) 2°
52.0 (outbd) ------------------------------------------------------------------------------------------------------------------------- 720/B 2433 130.83 241.88 786.2 27.17 (inbd) 2°
46.08 (outbd) ------------------------------------------------------------------------------------------------------------------------- 727-100, -200 1560 106 180.0 860.2 10.0 (pod) 2° ------------------------------------------------------------------------------------------------------------------------- 737-100 thru -500 980 93.0 134.46 625.6 16.14 1° 737-600 thru -900 1340 112.58 153.8 627.1 16.14 ------------------------------------------------------------------------------------------------------------------------- 747-100 thru -300 5500 195.67 327.78 1258.0 39.17 (inbd) 2°
69.5 (outbd) 747-400 5500 195.67 327.78 1258.0 39.17 (inbd) 2°
69.5 (outbd) 747SP 5500 195.67 327.78 1258.0 39.17 (inbd) 2°
69.5 (outbd) ------------------------------------------------------------------------------------------------------------------------- 757 (all) 1951 124.5 199.7 991.9 21.67 ------------------------------------------------------------------------------------------------------------------------- 767 (all) 3050 155.0 237.5 913.2 25.69 ------------------------------------------------------------------------------------------------------------------------- 777 (all) 4605 196.9 278.5 1174.5 32.67 -------------------------------------------------------------------------------------------------------------------------