About the Math Model
- Aerodynamics -
Presented To: NASA Ames ESTOL Sector / Cal Poly Team
By: Cassy Anthony and Natalia Sanchez
September 2006
San Luis Obispo, CA
MATH MODEL SCOPE (1.3 from Manual)
This document serves as an introduction to the QSRA Math Model that is currently
being replicated and adapted to the Cal Poly SimLab for comparison to the NASA
simulation. This overview is intended to provide an understanding of the concept and
type of model used in a real-time flight simulation.
Preface
A simulation system consists of a mathematical model, simulator hardware (computers, cab,
instrumentation), visual system (X-plane interface), and motion system (not yet functional at
the Cal Poly Lab). The math model is a key part of the total simulation system, which ideally
mirrors the behavior of the real aircraft in the areas under consideration.
The math model is the description and specification of the aircraft’s dynamic behavior. This
comprises the various motions of the airframe and the states and performance of the various
subsystems (engine, landing gear, and avionics). The math model considers all the external and
internal influences on the aircraft and defines the resultant states of the aircraft and its
subsystems (Thomas S. Alderete, NASA Ames Research Center, Moffett Field, CA).
The model is best presented by equations, diagrams, logic charts, tables, and graphs of data
including geometry, aerodynamic parameters, gain schedules, etc. These equations, diagrams,
and data comprise the actual math model, and can be found in the hard copy of the Quiet ShortHaul Research Aircraft Phase II Flight Simulation Mathematical Model Final Report (Boeing
Co. and NASA 1979). Two copies of this “manual” are available in the Aircraft Design Lab at
Cal Poly.
The digital computer program and its associated data is an implementation of the math model.
This is the current focus of this task, and for this reason all the graphs in the QSRA manual are
being digitized and the Simulink models replicated. The majority of the graphs correspond to
the Aerodynamic area of the model, and the Simulink models correspond to the Controls and
Propulsion sections. These are the three aspects of the model that will be elaborated
throughout this summer. For the final implementation of the model, all the data needs to be put
into code that would be compatible with the SimLab program.
There are several other documents that found in the Cal Poly Aircraft Design lab that are useful
in modeling the QSRA. Probably the most important of these is the QSRA Operations manual,
by Boeing. A listing of other Boeing/QSRA materials is available on the Swat server, under
the name “File Inventory (most recent date).xls”.
Model Breakdown
The math model uses a modular construction technique. The following modules are described
in the Final Report of the QSRA Phase II Flight Simulation Mathematical Model (1979):
1. Airplane Configuration
2. Propulsion System
3. Aerodynamic Forces and Moments
4. Flight Control Systems
5. Atmosphere Model
The highlights and limitations of each module of the QSRA simulation math model are
presented in Table 1.1 of the manual (pg. 73). Note that there is a wealth of data available in
the Figures and tables at the second portion of the math model, the tables alone do not describe
a complete aircraft model. The textual/equation based description must be consulted, and
figures/tables are substituted for equations, when specified by a reference in the textual model
description.
1. Airplane Configuration ( 3.0 Airplane Description pg. 9-10, 87-90)
 QSRA Geometry
 QSRA weight range, inertias, CG
 Landing gear (8.0 Sect. 57-60, 351)
2. Propulsion System (Sect. 4.0 pg. 11-15, 91-115)
 Separate math model for each YF-102 engine
 BLC system for L.E. and aileron BLC
 Mach (0 - 0.3), altitude and temperature effects
 Transient thrust dynamics and engine failure
 Cockpit throttle travel and engine instrument displays
 Inlet mass flow “ram” forces and moments
3. Aerodynamic Forces and Moments (Sect. 5.0 pg. 21-39, 116-284 Figures)
 All flap settings
 All control surfaces
 Leading edge and aileron BLC effects
 All gross thrust effects (thrust simulation for Cj>5)
 Horizontal tail aerodynamics (downwash, local flow fields, tail stall, etc)
 Model matches critical performance conditions
4. Flight Control Systems (Sect. 6.0 pg. 41-50, 285-341)
 Electrical and mechanical paths simulated
 Sensor model includes provisions for failure insertion
 Pitch control: mechanization and actuation properties, etc
 Flap control: control rates for USB flaps, lateral-directional control, spoilers and
ailerons rigging simulated, feel forces trim
 Hydraulic powered actuators
5. Atmosphere Model (Sect. 9.0 pg. 61-66, 352-357)
 Standard atmosphere (hot/cold)
 Low altitude wind and turbulence model: wind shear, etc
PERIPHERAL MATH MODELS (Sect 10.0 pg. 67-68, 358-360)
 Empennage Air Loads
 Maneuver Margin
The Simulation Interface at Cal Poly
The next section intends to serve as reference for the programming aspect of the simulation. It
comes from the Pheagle Documentation written by the SimLab operators (Keith Rothman), and
has been modified for the QSRA simulation. It includes a general overview of how the
different modules described above are coded into the Cal Poly simulation interface. This
simulation is based on the 1979 QSRA math model, which was designed to be compatible with
the Ames Research Center’s FSAA (Flight Simulation for Advanced Aircraft) simulation
facility. This facility includes standardized software packages written by the Computer
Sciences Corporation, the McFadden feel force loader system, and FSAA data acquisition
systems. The Cal Poly model, on the other hand, has been developed in Simulink and C++
with X-Plane graphics. All the software behind the simulation is based on programming done
by Cal Poly undergrad and graduate students.
The basic layout of the simulation interface can be illustrated as follows:
Each airplane is contained inside of the Airplane block (which initiates from the qsra_2_0.mdl
– Simulink model file). This provides a container for the whole system. The blocks under the
Airplane block, also known as classes, are composed of S-functions from C++ source code.
Each block pulls data from the library and the tables, which are input as text, h, and cpp files.
The Airplane block in Figure 1 can be considered the Mask and the Goto Visibility blocks.
Figure 1: Airplane Block Mask
Figure 2 below shows the inside of the Airplane block as modified for the QSRA Aircraft. The
blank template provided by an empty Airplane block for any airplane is illustrated in page 22 of
the Pheagle Documentation, as a reference. That template is the basis for all the models at the
Cal Poly SimLab.
Support Blocks
Display
Signal Routing
Forces and
Integration
Figure 2: Inside the Airplane Block
The blocks in this figure perform different functions needed for flight simulation. This
structure mirrors the modular layout described in the Model Breakdown section above, where
all the modules complement one another to simulate the overall behavior of the aircraft.
The flight simulation can be divided into four main parts:
 Forces and integration
 Support
 Display
 Multiplayer
The “Forces and Integration” blocks calculate the current forces, adds them together, and the
“SixDof” integrator takes that force and applies it to the simulated aircraft. Then using the
current aircraft data the “Support” blocks provide things like air density, temperature, and tells
the model when you have hit the ground, or broken apart. This data is passed back into the
forces blocks, and the cycle begins again.
The “Multiplayer” and “Display” blocks take the data from the integrator and communicate
with other player models, or with the graphics engine (currently X-Plane).
Adding an Aircraft into the Simulation
In order for the simulation to work with any aircraft, at least one file is needed: the
Aerodynamics Table file. This provides the majority of the data required for simulating the
aircraft. Unfortunately, the sole addition of this table will not allow for landings, accurate
engine data, correct graphical display, or proper ground registration by the crash detector.
In order to have a “complete” simulation you should correct following:
Table I. Main Settings
File/Settings
Aerodynamics
Table File
Gear file
Required for?
Simulation
Importance
Must include
Landing and takeoff
Crash file
Crashing
Engine Settings
CAS system
Graphics file
Airport file
Accuracy
Proper Pilot Control
X-Plane Model
Airport locations
Structure file
Structure
Airbrake settings
Airbrake
View file
X-Plane
Communication
If you want to interact with the ground this is a
must
If you want to interact with the ground this is a
must
Greatly improve accuracy
Depends on stability of aircraft
Visuals only, no impact on simulation
Only if the currently entered locations are
insufficient
If you need FAR requirement checking, this will
help you
If you do not have an aerodynamics table to
cover this, adjust these settings
Critical for X-Plane displaying, but no relevance
to the simulation accuracy
Aerodynamics
Introduction
Since Aerodynamics is a primary aspect of the simulation, and it constitutes about 70% of the
mathematical model, special emphasis has been placed on the implementation of this module.
As described in the QSRA Simulation report, the Aerodynamics math model includes the
following:
 Six component forces and moments for the set of conditions specified below:
o All flap settings
o All control surfaces and flap surface deflection
o Powered-lift blowing effects in all axes
o Leading-edge and aileron BLC effects
o Ground proximity effects
 The limitations of the model are also listed next.
o Ve < 200 knots
o Except for takeoff roll, data is limited to 8°    32°, CJ  5.0, and  25°
o Post-stall effects not fully simulated
o Fin maximum lift limits not simulated for large sideslip angles ≈ 25°
o Dynamic derivatives due to P, Q, R,  ,  are calculated from theory
o Model produces match with critical performance points
o Airplane takeoff performance cannot be based on YC-14 ground effect data
 Horizontal tail lift limits and downwash at tail included
Math Model Description
The data are built up around cruise, takeoff, go-around, and maximum descent flight
conditions. All the data are functionally dependent of the gross thrust momentum coefficient
(CJ), and a net BLC momentum coefficient (C ). Special provisions are made to extend the
axes buildup down to zero q. Note: the dynamic pressure in this model is denoted by q_dp
(control 32), otherwise the variable q indicates pitch rate. This provision allows simulation of
the takeoff ground roll maneuver (Report page 22).
The control surfaces and reference flap setting are defined in Figure 5.2-3 and 5.2-4 of the
report, pages 119 and 120 respectively. The two graphs illustrating the reference flap settings
were handled in Simulink instead of making them into text tables like the rest of the
Aerodynamics graphs. The sign convention used for the zero math model is shown in Figure
5.2-2, page 118 in the report.
The major elements of the aero math model (found in pages 22 and 23 of the QSRA report) can
be broken down into 4 categories:
 Aerodynamic Forces and Moments (Body Axis) – XA, YA, ZA, etc.
 Stability Axis Forces and Moments – XS, YS, ZS, etc.
 Direct Thrust Forces (CJ > 5) – XDT, YDT, ZDT, etc.
 KDT ( Gain for low q_dp)
Each category is represented by a set of equations that has been included in the Simulink file
Thurst_Forces.mdl as an Embedded function. These sets of equations come together as
illustrated in Figure 5.2-1b (pg. 117) to give the final equations of motion that govern the entire
behavior of the aircraft.
There are 2 kinds of input variables: Takeoff input variables and Independent Arguments. The
take off variables apply to low q_dp values and use the Direct Thrust Forces XDT, YDT, ZDT,
etc. The Independent Arguments come from the Aerodynamics graphs for CJ < 5, which are
the aero parameters in the text tables. These are also the stability axis forces and moments
denoted by XS, YS, ZS, etc that are fed into the embedded function as SDOFin. These are then
converted into Body axis forces (multiplying by KDT) to yield XA’, YA’, ZA’, etc. The forces
and moments from Direct Thrust and Body Axis are multiplied by their corresponding KDT and
then added together to obtain the final Aerodynamic Forces and Moments in Body Axis XA,
YA, ZA, etc (pages 22 and 23).
The next section expands on the connections between the Aerodynamics equations, the graphs,
and the code in the simulation. It pertains to the aerodynamic coefficients used in the
computation of the in the Stability Axis aerodynamic forces and moments.
Aerodynamics Equations in the Simulation Program
As mentioned in the preface, the final report of the QSRA simulation contains graphs, block
diagrams, schematics, and equations that complement each other to achieve the full
implementation of the math model. All the graphs in the Aerodynamics section have been
digitized and integrated into the SDOF model at the Cal Poly SimLab by means of a text table
containing all the Aerodynamic parameters: QSRA_Full_Table_08_23_06.txt. Each of the
graphs represents either an equation or a term in an equation from section 5 of the manual. For
example: section 5.3 lists the equations for Lift (Aerodynamic parameter CL). The first
equation is the general equation, which includes all the terms that affect lift such as Lift due to
USB flaps, Lift due to Ground Effect, Lift due to Spoilers, etc. Each of those terms has one or
several components that correspond to a graph (a table once it has been digitized). All the
graphs are found in the Aerodynamics section of the report pages 121 to 284. Change in lift
due to Ground Effect, for example, is the product of F_GE (Ground Effect Function) and
ΔCL_G (Lift Increment due to Ground Effect). Data for F_GE and ΔCL_G is shown in graphs
5.3-4a and 5.3-4b, respectively. An organizational chart in Aero Eqs. Flochart.doc shows how
all the components come together under each parameter.
The compilation of terms for the equations in sections 5.3 to 5.8 is done by means of a data
structure in C++ that groups variables and functions, and adds each component of the general
equation to its corresponding parameter (CL, CD, Cm, etc). This code alone is found in
Product Terms and functions.txt, in the QSRA_LIB folder, but it is actually added to the
QSRA_Full_Table to obtain the final input for the aerodynamics (e.g. Sim Table) in the
Airplane block. The functions called in this code are specified in the C++ file QSRA_LIB.cpp,
which contains the code form of all 60 equations required to accurately replicate the
Aerodynamic forces and moments acting on the aircraft. A list of these equations was put into
a spreadsheet for quick reference; the name of the Excel file is Equations for Sim.xls. A third
file is needed to tell C++ to make the functions available to the simulation program; this file is
called QSRA_LIB.h, name of .dll file and what it does.
There is one exception to the use of text tables in C++. Downwash free air is the only
parameter that was a four dimensional set of graphs in the QSRA Phase 2 Math Model
Report and since it is difficult to input a four dimensional table into C++, MATLAB
and Simulink were used instead. The free air downwash was put into the model as a
control because MATLAB was used.
It is very easy to establish a four dimensional table in MATLAB then saving that as a
.mat file and inputting that into Simulink to use it as a lookup table. Therefore, the only
aerodynamics graph that is not included in the C++ table lookup is the downwash free
air.
Another feature to notice about the math model is that a negative CD accounts for Thrust as
part of the Aerodynamic forces acting on the aircraft
A more detailed, programming-oriented overview of this system is provided next. It is
intended as a continuation of the Cal Poly Simulation Interface section, since it has been taken
and modified from the original Pheagle documentation at the SimLab.
The Aerodynamics Block (aerodyn_1_0.dll)
The Aerodynamics block generates aerodynamics forces based on a table-lookup system. It
takes data specifically from the Aerodynamics table mentioned in the previous section. The
table system supports 3-dimisional tables, DLL function externs, parameters, constants, linear
gains, and products. It can also support a varying number of controls. For the QSRA the
number of controls is 36 as of August 23, 2006, as listed in Controls List.xls for reference.
The block contains the s-function aerodyn_1_0, which handles the table-lookup in C++.
Because this block handles the constants of the aircraft, it also provides the Radii of Gyration
and Mass for the integrator.
Figure 3: Aerodynamics Block Mask
Parameters
The s-function aerodyn_1_0 takes one parameter: the name of the table file (default: simtable).
This parameter is provided by the Airplane Mask Dialog, where it can be changed to implement
the desired aircraft. The name of the QSRA table file is QSRA_Full_Table_(Latest Date),
which as of now is QSRA_Full_Table_08_23_06.txt.
Input Ports
There are 10 input ports into the aerodyn_1_0:
Name
Control Inputs
Speed of Sound
Density Altitude
Altitude
Orientation
Velocities
Omegas
Wind Velocities
Wind Accelerations
Model Reset Trigger
Units
radians
feet/second
slug/feet^3
feet
radians
feet/second
radians/second
feet/second
feet/second^2
Bool
Frame
n/a
n/a
n/a
LHLV
LHLV
Body
Body
LHLV
LHLV
n/a
Width
Number of controls
1
1
1
3
3
3
3
3
1
Tag Name
ElevatorAileronRudder
SpeedOfSound
Density
LLA
PhiThetaPsi
uvw
pqr
windV
windA
reset
Output Ports
There are 6 output ports from aerodyn_1_0:
Name
Forces and Moments
Alpha and Beta
Coefficients
Airspeed
Radii of gyration(sp)
Units
pounds and pounds/foot
Radians
Unitless
feet/second
Feet
Frame
Body
Body
n/a
LHLV
Body
Width
6
2
6 and parameters
3
6
Tag Name
n/a(Output)
AlphaBeta
n/a(Display)
uvwAirspeed
rGrayation
Mass of aircraft
slugs
n/a
1
Mass
Files
The aerodynamics files contain constants about the aircraft, followed by the tables. This is the
header of the table, and it required the following format:
Name
Take-off Gross Weight
Wing Area
Wing Span
Wing Chord
Radius of gyration( about x
Radius of gyration(about y
Radius of gyration(about z
Products of Inertia about xy
Products of Inertia about xz
Products of Inertia about yz
Number of Controls
Type of controls
Units/Options Note
pounds
feet^2
feet
feet
feet
feet
feet
feet
feet
feet
n/a
There should be a type for each control, each on a new line. The details
about each control type are as follows:
Normal
No action is taken
Trans_Deunit
Rot_Deunit
Number of parameters
Number of tables
n/a
n/a
Trans_Deunit – Deunitizes by dividing by q and Wing
Area
Rot_Deunit – Deunitizes by divinding by q, Wing Area,
and Wing Chord
Must be correct
Warning:
Order matters for the file header. The file reader assumes the order and reads
appropriately. If you miss a value or put them out of order the file reader may throw an error,
or the values will be wrong for the simulation.
In the actual text version that is implemented in the simulation, the header will look as follows:
39000
530
38.7
16
4.5411
lb
10.036
10.751
0.0
1.348
0.0
3
Normal
Normal
Normal
0
22
// TOGW (lbf)
// Area (ft^2)
// Span (ft)
// Chord (ft)
// rx (ft)
Ixx = 25000 slug ft^2
Weight = 39000
// ry (ft)
Iyy = 1.22E+05 slug ft^2
// rz (ft)
Izz = 1.40E+05 slug ft^2
// rxy
// rxz (ft)
Ixz = 2200 slug ft^2
// ryz
// Number of Controls (Elevator, Aileron, Rudder)
// Number of Parameters ()
// Number of Tables
Each table must start with what it affects. There are 7 possibilities:
Keyword (case-sensitive)
CL
CD
Cy
Cl
Cm
Cn
Parameter n
Name/Note
Lift Coefficient
Drag Coefficient
Side Force Coefficient
Roll Moment Coefficient
Pitch Moment Coefficient
Yaw Moment Coefficient
Parameter Number n (0-indexed)
On the next line you specify what type of lookup it is. There are 6 types of supported tables:
Keyword (case-sensitive)
Table
FunctionBoth the
function name and library
name are case sensitive.
Linear
Purpose
Adds a value from a one to three dimensional table lookup, with
interpolation, and optional extrapolation to the given parameter
Adds the return value of dynamic library function to the given parameter
Adds a variable times a constant to a given parameter
Adds a several variables multiplied together to a given parameter
Product
Abs
Constant
Adds the absolute value of the product of a variable and a constant
Adds a constant value to the given parameter
In the QSRA simulation only Tables, Products, Functions and Constants are used. The
functions and products are listed in a file named Product Terms and functions.txt. The code in
this text file is later added to the QSRA_Full _Table to obtain the final input for the
aerodynamic parameters (under Sim Table) in the Airplane block.
For the lookups you can use the following variables:
Keyword (case-sensitive)
Alpha
Beta
Mach
Airspeed
Altitude
Name
Angle-of-Attack
Sideslip Angle
Mach Number
True Airspeed
Altitude Above Sea-Level
Units/Note
radians
radians
n/a
feet/second
feet
Keyword (case-sensitive)
p
Name
Non-Dimensional Roll Rate
q
Non-Dimensional Pitch Rate
r
Non-Dimensional Yaw Rate
AlphaDot
Non- Dimensional Rate of
Change of Angle-of-Attack
Non-Dimensional Rate of
Change of Sideslip Angle
BetaDot
CL
CD
Cy
Cl
Cm
Cn
Parameter n
Control n
Lift Coefficient
Drag Coefficient
Side Force Coefficient
Roll Moment Coefficient
Pitch Moment Coefficient
Yaw Moment Coefficient
Parameter Number n
Control Number n
Units/Note
pb 

 pˆ  2V 
T 

qc 

 qˆ  2 V 
T 

rb 

 rˆ  2 V 
T 

 ˆ c 
   2V 
T 

 ˆ b 
 

2VT 

n/a
n/a
n/a
n/a
n/a
n/a
0-indexed
0-indexed
Table
The “Table” lookup-type is the mainstay of the table-lookup system, and is also the most
complex.
To demonstrate how to make a table this manual will take apart one that is already done.
CL
Table
2
Alpha 3
-5
0
Mach
0
0.5
0
5
3
1
.2
.5
.8
1.5
1.7
2.4
.8
1.0
1.5
0
After the “Table” keyword line, you need to put the number of dimensions, or axis variables.
The next 2 lines are the axis definitions.
On the first line of the axis definition, you need to provide three pieces of information’s with a
space or tab in between:

The Parameter keyword (Alpha, Beta, Parameter #, etc)

The number of data points in that axis

Whether to extrapolate that axis
On the second line of the axis definition you define the axis points for that axis, each values
separated by a space or tab.
Warning:
You need to ensure that the number of data points listed on the first line of the
definition matches the number of axis points on this line
Below is one complete axis definition, with three data points, and no extrapolation.
Alpha 3
-5
0
0
5
Warning:
You must have the number of axis definitions as you listed on line three of the
table definition.
Below is an example of what the actual table would look like:
Take notice that the first variable goes across the table horizontally. The second variable (if
there is one) goes down the table, vertically. Last the third variable (if there is one) is each
table, one after another. In summary, this is the general format for the tables:
Line #
1
2
3
4
5-6
What should be there?
A Parameter keyword
“Table”
Number of dimensions
Blank for clarity
Variable definition Variable name, axis length, to extrapolate
Axis definition
Repeat 5-6 for each variable.
Following Table
Function
The “Function” lookup-type uses a function from a dynamic library and adds it the given
parameter. On the line after the “Function” keyword, you need to specify the number of
variables to pass to the function. If you do not specify the correct number of variables to pass
into the function, the program may crash.
The next lines should be the parameters you want to pass to the function. After the variables,
you need to specify the name of the library. You should not add any system specific
extensions. These will be added automatically. For reference:
Library Name System
In the file
In the File System
QSRA_LIB
Windows
QSRA_LIB QSRA_LIB.dll
-nux systems QSRA_LIB libQSRA_LIB.so
Note: You must place the dynamic library in the MATLAB working directory, or it will
generate an error.
The next line is the function located in the library.
Warning:
Both the function name and library name are case sensitive.
Example:
CL
Function
4
Alpha
Control 5
Control 3
Parameter 4
QSRA_LIB
CL_function
Product
The “Product” lookup-type adds the product of several variables, parameters, controls and a
constant value to the given parameter. After the parameter and “Product” keyword, the next
line is the number of variables. The following lines are the variables to be multiplied together.
Below is an example:
Cm
Product
4
CL
Parameter 1
Alpha
Control 23
0.1
// Pitch Moment Coefficient (Cm General Parameter)
//
//
//
//
//
//
4 Variables
Lift Coefficient
Wing Arm (ft)
Angle of Attack
The 4th variable…
Constant that variables are multiplied by
Complete Example File
39000
530
38.7
16
4.5411
10.036
10.751
0.0
1.348
0.0
3
Normal
Normal
Normal
1
22
// TOGW (lbf)
// Area (ft^2)
// Span (ft)
// Chord (ft)
// rx (ft)
Ixx = 25000 slug ft^2
Weight = 39000
// ry (ft)
Iyy = 1.22E+05 slug ft^2
// rz (ft)
Izz = 1.40E+05 slug ft^2
// rxy
// rxz (ft)
Ixz = 2200 slug ft^2
// ryz
// Number of Controls (Elevator, Aileron, Rudder)
// Number of Parameters ()
// Number of Tables
CL
Table
2
Alpha 3
-5
0
Mach
0
0.5
0
5
3
1
.2
.5
.8
1.5
1.7
2.4
.8
1.0
1.5
0
CL
Function
4
Alpha
Control 0
Control 1
Control 2
QSRA_LIB
CL_function
Cm
Constant
-0.01
// Cm0
CL
Linear
AlphaDot
0.000
// CLAlphaDotHat
Cm
// Pitch Moment Coefficient
Product
2
// 2 Variables
CL
// Lift Coefficient
Parameter 0 // Wing Arm (ft)
0.1
// 1/Chord
Operations Manual
The QSRA Operations Manual, Boeing document number D340-13801 is very useful for
understanding through textual description of the systems of the QSRA, and how they are
operated. This is an integral part of being able to model the aircraft.
Additional Notes
Current Model Observations
6-27-06
 There are many aerodynamic model graphs that reference the deflection of the i’th USB
flap. This would seem to indicate that the USB flaps could potentially be positioned
differently. However, the flight manual indicates that the only reason that the USB
flaps would be in the case of an actuator failure, in which case the flap position monitor
circuit would shutdown the flap actuator, preventing further position disagreement. For
now, SimTables will be set up with provisions for each of 4 USB flap positions and also
for a reference flap position. This will provide for the best future expandability, but for
now the same value will be passed through for all USB flap deflections
 Left and right outboard flaps (non-USB) must be treated seperatly because in the event
of an engine failure in the landing configuration, the flap trim switch is used to retract
the flap opposite the engine failure to reduce the rolling moment due to asymmetric
blown lift
 Each of four spoilers must be treated separately, spoilers have 4 functions… See Opps
manual.
 The landing gear of the QSRA has been made non-retractable.
 QSRA airspeed redline (Do Not Exceed Speed) is 190 kts.
Simlab Observations
6-27-06
 Stick outputs from the SimLab pilot input are scaled from analogue -1 to +1.
 Current provisions for aerodynamic forces and moments may only be designed to be
input in tabular form. Aerodynamic parameters in QSRA math model are given in both
tabular and equation form. Further research is needed to determine the format for
passing equations into the SDOF model.
 Simlab model format has changed significantly from last year. Porting of current model
is in progress.
 The SimLab does not have nearly enough lever controls or switches to properly fly the
QSRA. A “engineers” control panel has been designed in the Simulink model to
address this issue, but depending of evolving requirements for an accurate simulation,
more physical controls may be desired.
 Need to find out sign conventions of SimLab