C*: Yaw
Vertical stabilizer (Photo credit: Wikipedia)
This post is about yaw control.
This is also the post for which I did not find many references.
Remember the yaw is the axis controlled by the rudder.
The rudder acts as any foil, providing a force dependant of its angle of attack.
This angle of attack is function of side slip angle (noted β)
and the rudder's deflection.
Basically, the rudder command an effort on the stabilizer, inducing a rotation around the yaw axis.
Note that the stabilizer also induce a force on this axis.
The stabilizer's force tend reduce sideway slip.
This momentum grows with speed.
On the way
The aircraft velocity is high, there is little risks to stall.
The goal is to avoid extra drag due to going sideways.
When the pilot's rudder is at neutral position, the aircraft must go straight ahead and the pilot should command the sideslip angle.
When performing turns, pilot's input to neutral must result coordinated turns (rudder not in neutral position).
Yaw control is also used for stabilisation purpose (e.g. yaw damping).
At low altitude
When really close to the ground, roll cannot be used to control airplane's trajectory.
The bank angle is limited due to both the ground clearance and the low speed (when near stall, having wings not leveled is not wise).
Thus, the rudder is used to control direction.
Normal law
Normal law is used in flight in normal condition. The A320 and the A380 does
not act the same way.
- the A320 adds pilots' input and flight-by-wire (FBW) orders . The FBW
system add orders so that with neutral pilot input, it handles yaw damping and
coordinates turns
- on the A380, the pilot's input commands sideslip angle.
Ground law
On the A380, the pilot control the yaw rate . I found no evidence for the A320,
thus I assume the FBW system adds no input.
Direct law
LaTeX makefile updated
My default LaTeX makefile evolved. Here is an update:
The makefile looks like:
LATEX=pdflatex
BIBTEX=bibtex
BIB=
RERUN='(There is undefined reference|Rerun to get (cross-references|the bars) right)'
%.pdf:%.tex
${LATEX} $<
@if [ -e $*.bbl ]; then ${BIBTEX} $* && ${LATEX} $< && ${LATEX} $< ; fi
@if egrep -q $(RERUN) $*.log ; then ${LATEX} $< ; fi
%.aux …
Functional Block diagram
How to make a block diagram
with \LaTeX?
This article is mainly inspired by tex example.
Here is an example
with tikz
resulting in the following figure:
The code:
\documentclass{article}
\usepackage[landscape,margin=1cm]{geometry}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows}
\begin{document}
\tikzstyle{block}=[draw,fill=red!20 …
Sail ship maneuvers
Sail ship not tacking (Proto credit: Wikipedia)
Maneuvering a sailship is not straight forward, especially when against the wind.
This article is focused on sail position when turning for
full-rigged sailships.
The main sources are naval action videos.
Preambule
The sailship has 2 or 3 masts.
The fore-mast (the one …
Read More
Back online
I've migrated the blog from wordpress to pelican. Static files, quite easy to
use.
The migration process went well. The pelican import tool is easy to use
and my rst linter highlighted the few errors done by the import tools (mainly
empty sections).
There are still few artefacts due to …
Read More
Seine flooding
[caption id="" align="alignright" width="350" class="zemanta-img"]
Seine, Paris, 1910. (Photo credit: Wikipedia)[/caption]
On this mounth, the Seine decided to flood Paris and its neighborouds, so I took my camera to take pictures. I realised:
I was not alone
[caption id="attachment_2567" align="alignnone" width="250"]
TV team …
Read More
UTF8, base64 and other encoding conversion
[caption id="" align="alignright" width="100" class="zemanta-img"]
encoding conversion (Photo credit: Wikipedia)[/caption]
A common way to represent binary files in ascii-only diplay is to use base64. This is also done a piece of software does not handle unicode: it manipulate its base64 representation.
Read More
GPG key renewal
[caption id="" align="alignright" width="75" class="zemanta-img"]
standard key (Photo credit: Wikipedia)[/caption]
What happen when a PGP key expire? Obvious answer: you can no longer securely use it. Nevertheless, you may not delete it as you must be able to read your encrypted files.
Basics step that should …
Read More
loop devices
Loop devices are used to acces any file as if it were a block device such as a disk. On GNU/linux, the canonical command to interact with loop devices is losetup. To list the next usable loop device: losetup -f
disk image loop mount …
Read More
awesome global shortcut
[caption id="" align="alignright" width="200" class="zemanta-img"]
Multimedia keyboard (Photo credit: Wikipedia)[/caption]
The awesome window manager does not provide GUI configuration tool.
Here is a litte how to to provide a feature using global shortcut, illustrated with wolume control.
Defining and identifying the feature and the shortcut
The …
Read More
Vertical stabilizer (Photo credit: Wikipedia)
