### Northrop T-38 Talon (JSBSim Model)

Version 1.1, released 9 April 2003
Configuration files for the FlightGear flight simulator www.flightgear.org.
By David Culp, April 2003, davidculp2@attbi.com
License: GPL (see http://www.gnu.org/licenses/gpl.html)

### Overview

This is a first attempt at using a single archive to distribute all the files needed to model an aircraft in FlightGear. This archive should be extracted into directory $FGROOT/Aircraft/T38. Some files will then need to be moved to other directories. I've attempted to keep as many of the files in directory $FGROOT/Aircraft/T38 as possible. Ideally I'd like to keep all the files in one directory, but currently FlightGear requires some of them to be placed elsewhere. The contents of the archive, and the directory in which each file or directory should reside, is listed below.

### Contents

filename | description | placement
--- | --- | ---
T38-read-me.html | This Readme file | $FGROOT/Aircraft/T38
T38.xml | The flight model | $FGROOT/Aircraft/T38
T38-set.xml | The main configuration file | $FGROOT/Aircraft
T38-sound.xml | The sound configuration file | $FGROOT/Aircraft/T38
T38-electrical.xml | The electrical system (unused) | $FGROOT/Aircraft/T38
J85-GE-5_sim.xml | The engine configuration file | $FGROOT/Engine
t38 | A shell script wrapper for fgfs | ~

directory name | description | placement
--- | --- | ---
Sounds | Contains .wav files and sound configuration for the T38 | $FGROOT/Aircraft/T38
Panels | Contains the T-38 instrument panel configuration | $FGROOT/Aircraft/T38
Models | Contains the T-38 3D model | $FGROOT/Aircraft/T38
Instruments | Contains T-38-specific instruments | $FGROOT/Aircraft/T38

### Bugs

I'm still fairly new to FlightGear, so some of these "bugs" may actually be features :)

bug | status
--- | ---
3D model has some bugs | The model is a reskinned version of the Captain Slug AT-38. There are gear parts extending upward through the wing. The model position has not been adjusted for FlightGear, so its wheels don't contact the ground properly. The gear and control surfaces don't move.
The ADI falls apart above about +/-20 degrees of pitch | Texture cropping is not available yet
The instrument panel is too small | This is actually a feature :) It is meant to increase visibility over the nose.
T-38's don't have that instrument at the right side of the panel | That's for flight test only. If you don't want it there just comment out the "Aero data" instrument in T38-panel.xml.
Where's the cheezy AOA Christmas tree? | Ignored for now.
The VOR doesn't work | Working on it.
The altimeter digital readout is out of sync | Rounding error. A 'truncate' unary operator is needed.

### Flying the T-38

Apply full throttle, afterburner is optional but recommended until 300 knots. Rotate at 140 knots. When airborne raise gear and flaps immediately. Climb at a shallow angle, less than 1000 fpm, until reaching 300 knots, then climb at 300 knots to 0.8 Mach. To land fly downwind at 300 knots clean, on base slow to 200 knots, extending gear and half flaps passing through 220 knots. On final extend full flaps and slow to 160 knots.
I recommend using the "hat switch" on your joystick to control stabilizer trim. I know most people like to use it for view changes, but you can't fly a jet without lots of stab trimming.
Let me know if you'd like more features, and if you have recent time in the T-38 let me know if this model flies reasonably close to the real airplane. It seems to lack power at altitude.

### Notes

The engine model uses the FGSimTurbine module of JSBSim. The afterburner can be activated in one of two ways, as defined by the AUGMETHOD value in the engine configuration file.
The "AOA buffet" sound activates at an AOA of 5.7 degrees. The sound should be a lower frequency buffet, and maybe I'll find the right sound someday. As far as the activation AOA, it's only a guess.
The light in the gear handle activates whenever throttle[0] is at idle and the gear handle is up. Not exactly how it works in the real airplane, but close.

15 May 2003