A Piper Seneca II for FlightGear
Last update: 2008-02-03
update
This page is partly outdated. Please also check
http://wiki.flightgear.org/flightgear_wiki/index.php?title=Piper_PA34-200T_Seneca_II
Introduction
3D model
Flightmodel
Screenshots
Features
TODO list
Changes
Download
Icing
HOWTO fly this Seneca
Legal stuff
Introduction
This is a model of a Piper
PA34-200T Seneneca II for use in FlightGear,
the open source flight simulator. I used a pilots operating handbook, a
real Seneca (D-GEJL) and some real flight performance data to build
this model.
3D model
The 3D model was made with help of AC3D
using the 3 view from the POH and some dimensions I picked from the
real airplane. For the textures I use Inkscape
to create scalable vector grahics and GIMP
for the raster graphics.
The image shows a screenshot of AC3D with the 4 views of the seneca's
outside.
Flightmodel
The flightmodel is JSBSim.
JSBSim is able to model comlex flight controls, supercharged piston
engines, ground (gear) reactions and calculates forces and moments
based on aerodynamic coefficients. To compute these coefficient I use DATCOM+, a nice tool that
takes the geometric dimensions as input and puts out the aerodynamic
coefficients that could be used by JSBSim. I have put a copy of my
input file here: SenecaII.dcm. The result
file is here: datcom.out.
I have modified the output generated by datcom to close the gap between
"theory" and "reality". I scaled the values for lift and drag
coefficients using calculated values of minimum drag and maximum lift
coefficients derived by the performance data of the POH.
Some screenshots
Standing on ground, engine stopped, prop feathered.
Closeup with doors open.
"I'm a poor lonesome cowboy and I'm a long way from home..."
Pilot's view (cockpit)
Pilot's view with instrument lights on
Reality
Pilot's view II (switch panel)
Flap lever, elevator and rudder trim, fuel selectors
Closeup: RPM and MP (left engine cutted), gear, parking-brake,
prop-deice and kr87 ADF radio
I love it! (fullsize version here)
High above LOWZ, Zell am See/Austria looking north(fullsize version here)
Features
Some goodies are working:
- FDM (JSB) performance data close approximation to POH
- All instruments true 3d models
- Clickable switch-panel
- Clickable autopilot
- Clickable deice control panel
- Clickable ki266 dme indicator
- Clickable kx165 nav/comm radios
- Clickable kr87 ADF radio, almost complete except countdown-timer
- Clickable hsi linked to NAV1
- Clickable ki266 dme indicator
- Clickable gma340 audio panel
- True slaved gyro simulation with KA51 control panel
- Clickable kra-10a radar altimeter
- Engine gauges for both engines
- Annunciator panel with test button
- Electrical system with load simulation and charging/discharging
of battery (under construction)
- Structural icing, visible at the temperature probe
- ...
TODO list
Here are the most annoying bugs and unimplemented features:
- Flight performance: single engine rate of climb to low
- Electrical: master switch noop
- Electrical: generator L/H and R/H produce the same output when on
- Autopilot: not modeling the Altimatic IIIc, just interface to
generic-autopilot
- Autopilot: only HDG and OMNI mode implemented
- Autopilot: ILS capture light noop
- FDM (JSB): EGT no indication because EGT is to low
- FDM (JSB): supercharger code should be improved
- FDM (JSB): make fuel source changeable and cuttable at runtime
- FDM (YASim): a complete noop
- gma340: on some buttons, the first click after program start gets
lost
- animate icing at the wings, stabilizer, fin, etc.
- probably lots more :-(
Changes
version 2006-11-23, releae 0.5
- Fixed bug in HSI, wrong deflection of glideslope indicator and transparency issue
- Added Roberto Inzerillo's nice nose gear and animations, new main gear
version 2006-11-15, release 0.4
- Added instruments lights for night flights
- Addes flashing strobe effect in clouds at night
- OBS knob on vor2 clickable
- subscale knob on altimeter clickable
- changes on aircraft 3d-model
version 2006-05-30, release 0.3
- Added structural icing
- Added Dave Perry's wonderful prop-disc animation
- Animated and clickable circuitbreaker panel (still electrical
nonfunction)
- Switchpanel: magneto switches operational
- Annunciator panel updated, fuelpump light ok, testbutton working
- Awful hack to propeller to throttle RPM to 1000 on idle when
standing still
- Switchpanel: fuel pump switches and primer working
- Fuel selectors: clickable and animated
version 2006-05-18, release 0.2
- improved JSBSim FDM
- minor changes to airframe 3d model
- added fuel flow gauge
- added circuit breaker panel
- added propeller-feather when rpm control is below 0.1
- added panel and light animations to gma340
- started lighting of instruments
Download
The Seneca II is part of the base package of FlightGear 1.0.0. The most current version
may be fetched from cvs. Please follow the instructions at
http://www.flightgear.org/.
Try running it with
fgfs --aircraft=SenecaII-jsbsim
Good luck and happy landings!
Icing
Since the Seneca provides anti- and deice equipment, I tried to
model structural icing into flightgear. A little nasal script does most
of the work:
First it reads the property nodes under /sim/model/icing where any
number of iceable elements configure the ice sensitive elements of the
aircraft.
Each element have a name, a sensitivity to icing, may have a salvage
control and the name of a output property where the collected amount of
ice is written to.
After the initial configuration, a timed loop is executed every 2
seconds. It
- calculates the spread by OAT and dewpoint
- checks visibility (see remark) to tell
if the aircraft is within clouds
- if the spread is below 0.1 degc and visibility is below 1000m,
assumes potential icing condition
- icing severity is calculated
- update all ice sensitive elements with the current icing
conditions
The icing severities are defined as
| severity |
inches |
per NM (still air) |
| NONE |
-0.3 |
80 |
| TRACE |
0.5 |
80 |
| LIGHT |
0.5 |
40 |
| MODERATE |
0.5 |
20 |
| SEVERE |
0.5 |
10 |
The rule for icing severity is:
| OAT_min |
OAT_max |
severity_min |
severity_max |
| -99 |
-30 |
NONE |
TRACE |
| -30 |
-20 |
TRACE |
LIGHT |
| -20 |
-12 |
LIGHT |
MODERATE |
| -12 |
-2 |
LIGHT |
SEVERE |
| -2 |
-0 |
NONE |
MODERATE |
| 0 |
999 |
NONE |
NONE |
When oat is above zero degc, Ice melts at a rate of 0.5" per 10NM at
10degc, the warmer the faster.
HOWTO fly this Seneca - a virtual checklist
Here is a simplified checklist to be used with this Seneca model.
This is a simplified version of my real checklist. Some items have been
omitted, some have been adapted to match the simulation.
** DO NOT USE THIS FOR A REAL FLIGHT **.
Speeds
- Rotate 71kts
- Vx 76 kts
- Vy 89 kts
- Initial climb 90 kts
- Cruise climb 100 kts
- Vref 90 kts
- Gear extension 130 kts
- Gear up 108 kts
- Flaps 10:138 kts, 25:121 kts, 40: 107 kts
Cockpit
- CABIN DOORS closed&checked
- ALL SWITCHES off
- GEAR LEVER down
- CIRCUIT BREAKERS checked
- PARKING BREAK set
Before Start Engine
- BATTERY MASTER on
- ATIS copied
- RADIOS off
Start Engine
- COWL FLAPS open
- FUEL SELECTORS on
- MIXTURE full rich
- PROPELLER high rpm
- THROTTLE full
- BEACON on
- MAGNETOS on
- PRIMER 5-10 secs
- THROTTLE 1" open
- ENG STARTER until 500 RPM
- THROTTLE 1000 RPM
After Start Engine
- THROTTLES 1000 RPM
- ALTERNATOR both on
- OIL PRESSURE checked
- AMP METER checked
- ANNUNCIATOR checked
- RADIOS on
- ALTIMETER set
- GYRO slave
Taxi
- BRAKES checked
- INSTRUMENTS checked
- FLIGHT CONTROLS checked
- X-FEED checked
- FLAPS checked and set
- TRIM set for t/o
Line-Up
- FUEL SELECTORS on
- LANDING LIGHT on
- ANTI ICE as required
- GYRO checked
After Takeoff
- LANDING LIGHT off
- GEAR/FLAPS up
- CLIMB POWER 31"/2450RPM
CRUISE
- CRUISE POWER set
- MIXTURE set
- COWL FLAPS close
APPROACH
- WEATHER copied
- ALTIMETER set
- FUEL SELECTOR on
- GYRO checked
FINAL
- GEAR down/3 green
- PROP high rpm
- MIXTURE rich
- FLAPS set
- LANDING LIGHT on
Legal stuff
All 3d models were created by Torsten (http://www.t3r.de/).
Some of the textures, models or panels are inspired or derived from
flightgear sources.
The chart texture for the enroute charts on the copilot seat is © Jeppesen Sanderson, Inc.
The gma340 texture is © Garmin
Ltd.
All my work presented on this page is released under Gnu General Public
License (http://www.gnu.org/licenses/gpl.html).
