Master List of Programs & Variables

File Name	Description of Code	Author(s)
class1wb_fixed.m	Class I Weight & Balance for Fixed Wing	Patrick LeGresley Ryan Vartanian
class2wb.m	Class II Weight & Balance	Patrick LeGresley
drag.m	Drag Analysis	Jennifer Owens
fixedwing.m	Performance Sizing for Fixed Wing Aircraft	Patrick LeGresley
jet.m	Weight sizing for jet aircraft	Patrick LeGresley
turboprop.m	Weight sizing for turboprop aircraft	Patrick LeGresley

Variable	Description	Units
A	Regression coefficient for weight sizing	-
a	Speed of sound	ft/sec
A_g_main	Parameter for landing gear weight calculation	-
A_g_nose	Parameter for landing gear weight calculation	-
A_inl	Inlet area	ft²
A_max	Maximum cross sectional area of fuselage	ft²
aileron_wing_ratio	Ratio of aileron area to wing ref. area	-
AR_ht	Horizontal tail aspect ratio	-
AR_vt	Vertical tail aspect ratio	-
AR_wing	Wing aspect ratio	-
B	Regression coefficient for weight sizing	-
B_g_main	Parameter for landing gear weight calculation	-
B_g_nose	Parameter for landing gear weight calculation	-
b_ht	Horizontal tail span	ft
b_vt	Vertical tail span	ft
b_wing	Wing span	ft
C	Parameter for weight sensitivities	-
C_g_main	Parameter for landing gear weight calculation	-
C_g_nose	Parameter for landing gear weight calculation	-
c_j_cruise	Cruise specific fuel consumption (jet)	lb/lb/hr
c_j_loiter	Loiter specific fuel consumption (jet)	lb/lb/hr
C_L_alpha_h	Lift curve slope of horizontal tail	1/rad
C_L_alpha_wf	Lift curve slope of wing-fuselage	1/rad
c_p_cruise	Cruise specific fuel consumption (turboprop)	lb/hp/hr
c_p_loiter	Loiter specific fuel consumption (turboprop)	lb/hp/hr
c_r_ht	Horizontal tail root chord	ft
c_r_vt	Vertical tail root chord	ft
c_r_wing	Wing root chord	ft
c_t_ht	Horizontal tail tip chord	ft
c_t_vt	Vertical tail tip chord	ft
c_t_wing	Wing tip chord	ft
CD	Drag Coefficient	-
CD_L	Drag coefficient during landing ground roll	-
CD_nozzle_base	Nozzle base drag coefficient	-
CD_oper	Drag coefficient during cruise	-
CD_p	Parasite drag coefficient	-
CD_p_ht	Horizontal tail parasite drag coefficient	-
CD_p_vt	Vertical tail parasite drag coefficient	-
CD_p_wing	Wing parasite drag coefficient	-
CD_pi_upsweep	Fuselage upsweep drag coefficient	-
CD_to	Drag coefficient during takeoff ground roll	-
Cdpmisc	Markup in CDp for miscellaneous items	%
Cf_fus	Fuselage skin friction coefficient	-
Cf_ht	Horizontal tail skin friction coefficient	-
Cf_inter	Markup in Cf due to interference effects	%
Cf_markup	Markup in Cf due to roughness	%
Cf_vt	Vertical tail skin friction coefficient	-
Cf_wing	Wing skin friction coefficient	-
Cfinterp	Data for Cf lookup table	-
CL	Lift Coefficient	-
CL_ht	Lift coefficient of the horizontal tail	-
CL_L	Lift coefficient during landing ground roll	-
CL_max_L	Maximum lift coefficient in the landing configuration	-
CL_max_to	Maximum lift coefficient in the takeoff configuration	-
CL_oper	Lift coefficient during cruise	-
CL_to	Lift coefficient during takeoff ground roll	-
CLover	Data for comp. drag lookup table	-
commercial	= 1 to make calculations for commercial version	-
comp_wts	Component weights for Class I W&B	lb
composite	Factor to account for use of composite structure	-
D	Parameter for weight sensitivities
D_exit	Exit diameter of engine	ft
D_g_main	Parameter for landing gear weight calculation	-
D_g_nose	Parameter for landing gear weight calculation	-
D_p	Propeller diameter	ft
Deff	Effective diameter of fuselage	ft
deltaCD_c	Increment in drag coeff. due to compressibility	-
deltaCDc	Data for comp. drag curve fit data	-
deltax_wing	Distance from start of fuselage constant cross section to wing leading edge	ft
deps_h_da	Downwash gradient at horizontal tail	-
drag	Drag force	lb
e	Span efficiency factor for wing	-
e_inviscid	Inviscid span efficiency factor for wing	-
E_loiter	Loiter time	hr
eht	Span efficiency factor for h. tail	-
eht_inviscid	Inviscid span efficiency factor for h. tail	-
emptyweightsensitivity	Sensitivity of takeoff weight to empty weight	-
epsilon	Tolerance for iteration convergence	-
F	Parameter for weight sensitivities	-
f_fus	Equivalent parasite area for fuselage	ft²
f_gaps_ht	Additional f_vt due to gap drag	ft²
f_gaps_vt	Additional f_ht due to gap drag	ft²
f_gaps_wing	Increment to f_wing for gap drag	ft²
f_ht	Equivalent parasite area for horizontal tail	ft²
f_markdown	Markdown in f due to compressibility	%
f_total	Total parasite drag area	-
f_vt	Equivalent parasite area for vertical tail	ft²
f_wing	Equivalent parasite area for wing	ft²
fineness	Fineness ratio of fuselage	-
fuelflow_TO	Takeoff fuel flow	lb/sec
g	gravitational acceleration	ft/sec²
gamma	Ratio of specific heats	-
h	Altitude	ft
h_max	Maximum height of fuselage	ft
hl	h/l at 75% of tail length (see AA241 course notes)	-
i	Matrix index	-
iter	Number of iterations	-
K	Factor for lift dependent viscous drag	-
K_api	Factor for api weight calculations	-
K_apu	Factor for APU weight calculation	-
K_bc	Factor for baggage handling equip weight	-
K_buf	Factor for buffet weight calculation	-
K_fc	Factor for flight control weight calculation	-
K_fsp	Fuel density (lb/gal)	lb/gal
K_fus	Form factor for fuselage	-
K_fus	Factor for fuselage weight calculation	-
K_g_r	Factor for landing gear location	-
K_h	Factor for h. tail weight calculation	-
K_ht	Form factor for horizontal tail	-
K_hydr	Factor for hydraulics weight calculation	-
K_inl	Factor for inlet location	-
K_lav	Factor for lavatory weight calculation	-
K_prop_1	Factor for calculation of propeller weight	lb
K_pt	Factor for calculation of paint weight	-
K_v	Factor for v. tail weight calculation	-
K_vt	Form factor for vertical tail	-
K_wing	Form factor for wing	-
L	Fuselage length	ft
l_h	Distance from wing a.c. to h. tail a.c.	ft
l_n	Nacelle length from inlet lip to compressor face	ft
l_pax	Length of passenger cabin	ft
l_s_m	Shock strut length for main gear	ft
l_v	Distance from wing a.c. to v. tail a.c.	ft
landing	Landing ground roll matrix for plotting results	ft
LD_app	Lift to drag ratio in approach configuration	-
LD_cruise	Cruise lift to drag ratio	-
LD_loiter	Loiter lift to drag ratio	-
LD_oper	Lift to drag ratio during cruise	-
Ldsensitivity	Sensitivity of takeoff weight to lift to drag ratio	lb
lift	Lift force	lb
M	Mach number	-
M_ff	Mission fuel fraction	-
M_h	Maximum Mach number at sea level	-
m_tfo	Mass of trapped fuel and oil (as % of W_to)	%
mac_ht	Horizontal tail mean aerodynamic chord	ft
mac_vt	Vertical tail mean aerodynamic chord	ft
mac_wing	Wing mean aerodynamic chord	ft
Mcc	Crest critical Mach number for the wing	-
Mdiv	Drag divergence Mach number	-
mgc_wing	Wing mean geometric chord	ft
Minfperp	Data for comp. drag lookup table	-
Mperp	Wing perpendicular Mach number	-
Mratio	Data for comp. drag curve fit data	-
mu	Coefficient of viscosity	??
mu_brake	Braking friction coefficient	-
mu_fric	Ground friction coefficient	-
n	Matrix index	-
N_bl	Number of blades per propeller	-
N_cc	Number of cabin crew	-
N_cr	Number of crew members	-
N_e	Number of engines	-
N_fdc	Number of flight deck crew	-
N_inl	Number of inlets	-
N_p	Number of propellers	-
n_p_cruise	Cruie propeller efficiency	-
n_p_loiter	Loiter propeller efficiency	-
N_pax	Number of passengers	-
N_pax_mil	Number of military passengers	-
N_pil	Number of pilots	-
N_t	Number of separate fuel tanks	-
n_ult	Ultimate load factor	g's
n_ult_L	Ultimate load factor for landing	g's
N_vt	Number of vertical tails	-
needtoiterate	= 1 if iteration needs to continue	-
numbcomps	# of components in Class II weight breakdown	-
P_c	Design ultimate cabin pressure	psi
P_to	Takeoff power	hp
P2	Maximum static pressure at compressor face	psi
payload	Matrix of tfo, crew, fuel, and payload weights and c.g. locations	lb, ft, ft, ft
payloadsensitivity	Sensitivity of takeoff weight to payload weight	-
propeffsensitivity	Sensitivity of takeoff weight to cruise prop efficiency	lb
qbar_D	Design dive dynamic pressure in psf	psf
R	Gas constant	??
R_cruise	Cruise range	nm
R_design	Design range	nm
r_fus	Fuselage radius	ft
rangesensitivity	Sensitivity of takeoff weight to range	lb/nm
Re_fus	Fuselage Reynolds number	-
Re_ht	Horizontal tail Reynolds number	-
Re_vt	Vertical tail Reynolds number	-
Re_wing	Wing Reynolds number	-
Reyn	Data for Cf lookup table	-
rho	Air density	slugs/ft³
rho_o	Reference density	slugs/ft³
s	Interference factor between fuselage and wing	-
S_aileron	Aileron area	ft²
S_fgs	Fuselage gross shell area	ft²
S_ref	Wing reference area	ft²
S_rudder	Rudder area	ft²
S_wet_ht	Horizontal tail wetted area	ft²
S_wet_vt	Vertical tail wetted area	ft²
S_wet_wing	Wing wetted area	ft²
S_wing_exposed	Exposed reference area of the wing	ft²
sfcsensitivity	Sensitivity of takeoff weight to sfc	lb/(lb/lb/hr) [jet] hp-hr [turboprop]
sg_l	Matrix for integration of landing distance	ft
sg_to	Matrix for integration of takeoff distance	ft
sht	Interference factor between fuselage and h. tail	-
Sht_ref	Horizontal tail reference area	ft²
SM	Static margin	%
stepsize	Step size used in numerical integration	-
sumpayload	Summation of columns in payload matrix	lb, ft, ft, ft
sumweights	Summation of columns in weights matrix	lb, ft, ft, ft
Svt_ref	Vertical tail reference area	ft²
sweep_ht	Horizontal tail quarter chord sweep angle	deg
sweep_ht_50c	H. tail semi chord sweep angle	deg
sweep_vt	Vertical tail quarter chord sweep angle	deg
sweep_vt_50c	Vertical tail semi chord sweep angle	deg
sweep_wing	Wing quarter-chord sweep angle	deg
sweep_wing_50c	Wing semi chord sweep angle	deg
Swet_fuselage	Fuselage wetted area	ft²
Swet_total	Total airplane wetted area	-
T	Thrust force	lb
T_o	Reference temperature	R
t_r_ht	H. tail root thickness	ft
t_r_vt	V. tail root thickness	ft
t_r_wing	Wing root thickness	ft
T_to	Takeoff installed static thrust	lb
t1,t2,t3	Figure titles	-
takeoffdist	Takeoff ground roll matrix for plotting results	ft
taper_ht	Horizontal tail taper ratio	-
taper_vt	Vertical tail taper ratio	-
taper_wing	Wing taper ratio	-
tau_wing	Ratio of tip thickness ratio to root thickness ratio	-
tc_avg_ht	Horizontal tail average thickness to chord ratio	-
tc_avg_vt	Vertical tail average thickness to chord ratio	-
tc_avg_wing	Wing average thickness to chord ratio	-
tc_max_wing	Wing maximum thickness to chord ratio	-
tcperp	Data for comp. drag lookup table	-
theta	Temperature ratio	-
thrustweight	T/W matrix for plotting results	-
tiltwing	= 1 to make calculations for tiltwing version	-
trans	Data for Cf lookup table	-
TW	Takeoff thrust to weight ratio	-
u	Factor used to calculate e_inviscid	-
v	Velocity matrix (used for internal calculations)	ft/sec
V	Speed	knots
V_C	Design cruise speed in keas	keas
V_cruise	Cruise speed	knots
V_D	Design dive speed in keas	keas
V_h	Maximum level speed at sea level in keas	keas
V_lo	Liftoff speed	ft/sec
V_loiter	Loiter speed	knots
V_pax	Volume of passenger cabin	ft³
V_pr	Pressurized volume	ft³
V_td	Touchdown speed	ft/sec
Vs_L	Stall speed in landing configuration	ft/sec
Vs_to	Stall speed in the takeoff configuration	ft/sec
Vwf	Wing fuel volume	ft³
W	Weight	lb
W_api	Average weight of api method	lb
W_api_GD	Weight of api from GD method	lb
W_api_GD_mil	Weight of api from GD military method	lb
W_api_Tor	Weight of api from Tor method	lb
W_apu	Weight of APU	lb
W_aux	Weight of auxiliary gear	lb
W_bc	Weight of baggage handling equipment	lb
W_crew	Crew weight	lb
W_e	Empty weight	lb
W_e_allowable	Allowable empty weight from regression coefficients	lb
W_e_ClassII	Class II empty weight	lb
W_e_tentative	Initialized weight value to start weight sizing	lb
W_ec	Weight of engine controls	lb
W_els	Average weight of electrical system	lb
W_els_GD	Weight of electrical system from GD method	lb
W_els_Tor	Weight of electrical system from Tor method	lb
W_eng	Weight of all engines	lb
W_eng_single	Weight of one engine	lb
W_ess	Weight of engine starter	lb
W_fc	Average flight control weight	lb
W_fc_GD_ct	Flight control weight from GD method	lb
W_fc_GD_mil	Flight control weight from GD military method	lb
W_fc_Tor_ct	Flight control weight from Tor method	lb
W_fs	Weight of fuel system	lb
W_fuel	Fuel weight	lb
W_fur_comm	Weight of furnishings for commercial version	lb
W_fur_GD	Weight of furnishings from GD method	lb
W_fur_GD_mil	Weight of furnishings from GD mil method	lb
W_fur_mil	Weight of furnishings for military version	lb
W_fur_Tor	Weight of furnishings from Tor method	lb
W_fus	Average fuselage weight	lb
W_fus_GD	Fuselage weight from GD method	lb
W_fus_Tor	Fuselage weight from Torenbeek method	lb
W_fus_USAF	Fuselage weight from USAF method	lb
W_fus_USN	Fuselage weight from USN method	lb
W_gear	Average landing gear weight	lb
W_gear_GD	Landing gear weight from GD method	lb
W_gear_main	Main gear weight	lb
W_gear_nose	Nose gear weight	lb
W_gear_Tor	Landing gear weight from Torenbeek method	lb
W_gear_Tor_main	Main gear weight from Torenbeek method	lb
W_gear_Tor_nose	Nose gear weight from Torenbeek method	lb
W_gear_USAF	Landing gear weight from USAF method	lb
W_gear_USN	Landing gear weight from USN method	lb
W_guess	Initial weight guess for weight sizing	lb
W_ht	Average H. tail weight	lb
W_ht_GD	H. tail weight from GD method	lb
W_ht_Tor	H. tail weight from Torenbeek method	lb
W_ht_USAF	H. tail weight from USAF method	lb
W_hydr	Weight of hydraulic system	lb
W_iae	Average weight of iae	lb
W_iae_GD	Weight of iae from GD method	lb
W_iae_Tor	Weight of iae from Tor method	lb
W_L	Landing weight	lb
w_max	Maximum width of fuselage	ft
w_max	Fuselage maximum width	ft
W_MZF	Maximum zero fuel weight	lb
W_nac	Average nacelle weight	lb
W_nac_GD	Nacelle weight from GD method	lb
W_nac_Tor	Nacelle weight from Torenbeek method	lb
W_oe	Operating empty weight	lb
W_oe_tentative	Tentative operating empty weight for weight sizing	lb
W_osc	Weight of cooling fluids	lb
W_ox	Average weight of oxygen system	lb
W_ox_GD	Weight of oxygen system from GD method	lb
W_ox_Tor	Weight of oxygen system from Tor method	lb
W_p	Average weight of propulsion controls	lb
W_p_GD	Weight of propulsion controls from GD method	lb
W_p_Tor	Weight of propulsion controls from Tor method	lb
W_payload	Payload weight	lb
W_prop	Propeller weight	lb
W_pt	Weight of paint	lb
W_tfo	Weight of trapped fuel and oil	lb
W_to	Takeoff weight	lb
W_to_ClassII	Class II takeoff weight	-
W_to_old	Takeoff weight from previous weight iteration	lb
W_vt	Average V. tail weight	lb
W_vt_GD	V. tail weight from GD method	lb
W_vt_Tor	V. tail weight from Torenbeek method	lb
W_vt_USAF	V. tail weight from USAF method	lb
W_w	Average wing weight	lb
W_w_GD	Wing weight from GD method	lb
W_w_Tor	Wing weight from Torenbeek method	lb
W_w_USAF	Wing weight from USAF method	lb
weights	Class II weights and c.g. locations	lb, ft, ft, ft
wf_climb	Weight fraction for climb segment	-
wf_cruise	Weight fraction for cruise segment	-
wf_descent	Weight fraction for descent segment	-
wf_landtaxi	Weight fraction for land/taxi segment	-
wf_loiter	Weight fraction for loiter segment	-
wf_takeoff	Weight fraction for takeoff segment	-
wf_taxi	Weight fraction for taxi segment	-
wf_warmup	Weight fraction for warmup segment	-
wingload	Wing loading matrix for plotting results	lb/ft²
WS	Takeoff Wing Loading	lb/ft²
x_ac_A	x-location of airplane aerodynamic center	ft
x_ac_h	x-location of h. tail aerodynamic center	ft
x_ac_wf	x-location of wing-fuselage aerodynamic center	ft
x_cg_comp	x-cg locations for Class I W&B	ft
x_cg_crew	x-cg location for crew	ft
x_cg_empty	x-cg location for empty airplane	ft
x_cg_fuel	x-cg location for fuel	ft
x_cg_payload	x-cg location for payload	ft
x_cg_takeoff	x-cg location at takeoff weight	ft
x_cg_tfo	x-cg location for trapped fuel and oil	ft
xtc_fus	Transition location for fuselage	-
xtc_ht	Transition location for horizontal tail	-
xtc_vt	Transition location for Vertical tail	-
xtc_wing	Transition location for wing	-
y_cg_empty	y-location of empty weight c.g.	ft
z_cg_empty	z-location of empty weight c.g.	ft
z_h	Dist from v. tail root to where h. tail is mounted on v. tail	ft

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