<s>
In	O
aviation	O
,	O
autoland	B-Device
describes	O
a	O
system	O
that	O
fully	O
automates	B-Application
the	O
landing	O
procedure	O
of	O
an	O
aircraft	O
's	O
flight	O
,	O
with	O
the	O
flight	O
crew	O
supervising	O
the	O
process	O
.	O
</s>
<s>
Autoland	B-Device
systems	O
were	O
designed	O
to	O
make	O
landing	O
possible	O
in	O
visibility	O
too	O
poor	O
to	O
permit	O
any	O
form	O
of	O
visual	O
landing	O
,	O
although	O
they	O
can	O
be	O
used	O
at	O
any	O
level	O
of	O
visibility	O
.	O
</s>
<s>
Autoland	B-Device
may	O
be	O
used	O
for	O
any	O
suitably	O
approved	O
instrument	O
landing	O
system	O
(	O
ILS	O
)	O
or	O
microwave	O
landing	O
system	O
(	O
MLS	O
)	O
approach	O
,	O
and	O
is	O
sometimes	O
used	O
to	O
maintain	O
currency	O
of	O
the	O
aircraft	O
and	O
crew	O
,	O
as	O
well	O
as	O
for	O
its	O
main	O
purpose	O
of	O
assisting	O
an	O
aircraft	O
landing	O
in	O
low	O
visibility	O
and/or	O
bad	O
weather	O
.	O
</s>
<s>
Autoland	B-Device
requires	O
the	O
use	O
of	O
a	O
radar	O
altimeter	O
to	O
determine	O
the	O
aircraft	O
's	O
height	B-Application
above	O
the	O
ground	O
very	O
precisely	O
so	O
as	O
to	O
initiate	O
the	O
landing	O
flare	O
at	O
the	O
correct	O
height	B-Application
(	O
usually	O
about	O
)	O
.	O
</s>
<s>
For	O
safety	O
reasons	O
,	O
once	O
autoland	B-Device
is	O
engaged	O
and	O
the	O
ILS	O
signals	O
have	O
been	O
acquired	O
by	O
the	O
autoland	B-Device
system	O
,	O
it	O
will	O
proceed	O
to	O
landing	O
without	O
further	O
intervention	O
.	O
</s>
<s>
It	O
can	O
be	O
disengaged	O
only	O
by	O
completely	O
disconnecting	O
the	O
autopilot	O
(	O
this	O
prevents	O
accidental	O
disengagement	O
of	O
the	O
autoland	B-Device
system	O
at	O
a	O
critical	O
moment	O
)	O
or	O
by	O
initiating	O
an	O
automatic	O
go-around	O
.	O
</s>
<s>
At	O
least	O
two	O
and	O
often	O
three	O
independent	O
autopilot	O
systems	O
work	O
in	O
concert	O
to	O
carry	O
out	O
autoland	B-Device
,	O
thus	O
providing	O
redundant	O
protection	O
against	O
failures	O
.	O
</s>
<s>
Most	O
autoland	B-Device
systems	O
can	O
operate	O
with	O
a	O
single	O
autopilot	O
in	O
an	O
emergency	O
,	O
but	O
they	O
are	O
only	O
certified	O
when	O
multiple	O
autopilots	O
are	O
available	O
.	O
</s>
<s>
The	O
autoland	B-Device
system	O
's	O
response	O
rate	O
to	O
external	O
stimuli	O
work	O
very	O
well	O
in	O
conditions	O
of	O
reduced	O
visibility	O
and	O
relatively	O
calm	O
or	O
steady	O
winds	O
,	O
but	O
the	O
purposefully	O
limited	O
response	O
rate	O
means	O
they	O
are	O
not	O
generally	O
smooth	O
in	O
their	O
responses	O
to	O
varying	O
wind	O
shear	O
or	O
gusting	O
wind	O
conditions	O
–	O
i.e.	O
,	O
not	O
able	O
to	O
compensate	O
in	O
all	O
dimensions	O
rapidly	O
enough	O
–	O
to	O
safely	O
permit	O
their	O
use	O
.	O
</s>
<s>
Autoland	B-Device
capability	O
has	O
seen	O
the	O
most	O
rapid	O
adoption	O
in	O
areas	O
and	O
on	O
aircraft	O
that	O
must	O
frequently	O
operate	O
in	O
very	O
poor	O
visibility	O
.	O
</s>
<s>
Airports	O
troubled	O
by	O
fog	O
on	O
a	O
regular	O
basis	O
are	O
prime	O
candidates	O
for	O
Category	O
III	O
approaches	O
,	O
and	O
including	O
autoland	B-Device
capability	O
on	O
jet	O
airliners	O
helps	O
reduce	O
the	O
likelihood	O
that	O
they	O
will	O
be	O
forced	O
to	O
divert	O
by	O
bad	O
weather	O
.	O
</s>
<s>
Autoland	B-Device
is	O
highly	O
accurate	O
.	O
</s>
<s>
Previously	O
,	O
autoland	B-Device
systems	O
have	O
been	O
so	O
expensive	O
that	O
they	O
were	O
rarely	O
used	O
on	O
small	O
aircraft	O
.	O
</s>
<s>
However	O
,	O
as	O
display	O
technology	O
has	O
developed	O
the	O
addition	O
of	O
a	O
head	B-Application
up	I-Application
display	I-Application
(	O
HUD	B-Application
)	O
allows	O
for	O
a	O
trained	O
pilot	O
to	O
manually	O
fly	O
the	O
aircraft	O
using	O
guidance	O
cues	O
from	O
the	O
flight	O
guidance	O
system	O
.	O
</s>
<s>
This	O
significantly	O
reduces	O
the	O
cost	O
of	O
operating	O
in	O
very	O
low	O
visibility	O
,	O
and	O
allows	O
aircraft	O
that	O
are	O
not	O
equipped	O
for	O
automatic	B-Device
landings	I-Device
to	O
make	O
a	O
manual	O
landing	O
safely	O
at	O
lower	O
levels	O
of	O
look	O
ahead	O
visibility	O
or	O
runway	O
visual	O
range	O
(	O
RVR	O
)	O
.	O
</s>
<s>
In	O
1989	O
,	O
Alaska	O
Airlines	O
was	O
the	O
first	O
airline	O
in	O
the	O
world	O
to	O
manually	O
land	O
a	O
passenger-carrying	O
jet	O
(	O
Boeing	O
B727	O
)	O
in	O
FAA	O
Category	O
III	O
weather	O
(	O
dense	O
fog	O
)	O
made	O
possible	O
with	O
the	O
head-up	B-Application
guidance	I-Application
system	I-Application
.	O
</s>
<s>
Commercial	O
aviation	O
autoland	B-Device
was	O
initially	O
developed	O
in	O
the	O
United	O
Kingdom	O
,	O
as	O
a	O
result	O
of	O
the	O
frequent	O
occurrence	O
of	O
very	O
low	O
visibility	O
conditions	O
in	O
winter	O
in	O
North-west	O
Europe	O
.	O
</s>
<s>
One	O
pilot	O
is	O
assigned	O
the	O
task	O
of	O
accurate	O
instrument	O
flying	O
while	O
the	O
other	O
assesses	O
the	O
visual	O
cues	O
available	O
at	O
decision	O
height	B-Application
,	O
taking	O
control	O
to	O
execute	O
the	O
landing	O
once	O
satisfied	O
that	O
the	O
aircraft	O
is	O
in	O
fact	O
in	O
the	O
correct	O
place	O
and	O
on	O
a	O
safe	O
trajectory	O
for	O
a	O
landing	O
.	O
</s>
<s>
The	O
result	O
was	O
a	O
major	O
improvement	O
in	O
the	O
safety	O
of	O
operations	O
in	O
low	O
visibility	O
,	O
and	O
as	O
the	O
concept	O
clearly	O
incorporates	O
vast	O
elements	O
of	O
what	O
is	O
now	O
known	O
as	O
crew	B-Error_Name
resource	I-Error_Name
management	I-Error_Name
(	O
although	O
predating	O
this	O
phrase	O
by	O
some	O
three	O
decades	O
)	O
it	O
was	O
expanded	O
to	O
encompass	O
a	O
far	O
broader	O
spectrum	O
of	O
operations	O
than	O
just	O
low	O
visibility	O
.	O
</s>
<s>
The	O
components	O
of	O
all	O
landings	O
are	O
the	O
same	O
,	O
involving	O
navigation	O
from	O
a	O
point	O
at	O
altitude	B-Application
en	O
route	O
to	O
a	O
point	O
where	O
the	O
wheels	O
are	O
on	O
the	O
desired	O
runway	O
.	O
</s>
<s>
BEA	O
's	O
flight	O
technical	O
personnel	O
were	O
heavily	O
involved	O
in	O
BLEU	O
's	O
activities	O
in	O
the	O
development	O
of	O
Autoland	B-Device
for	O
its	O
Trident	O
fleet	O
from	O
the	O
late	O
1950s	O
.	O
</s>
<s>
The	O
basic	O
concept	O
of	O
autoland	B-Device
flows	O
from	O
the	O
fact	O
that	O
an	O
autopilot	O
could	O
be	O
set	O
up	O
to	O
track	O
an	O
artificial	O
signal	O
such	O
as	O
an	O
Instrument	O
Landing	O
System	O
(	O
ILS	O
)	O
beam	O
more	O
accurately	O
than	O
a	O
human	O
pilot	O
could	O
–	O
not	O
least	O
because	O
of	O
the	O
inadequacies	O
of	O
the	O
electro-mechanical	O
flight	O
instruments	O
of	O
the	O
time	O
.	O
</s>
<s>
If	O
the	O
ILS	O
beam	O
could	O
be	O
tracked	O
to	O
a	O
lower	O
height	B-Application
then	O
clearly	O
the	O
aircraft	O
would	O
be	O
nearer	O
to	O
the	O
runway	O
when	O
it	O
reached	O
the	O
limit	O
of	O
ILS	O
usability	O
,	O
and	O
nearer	O
to	O
the	O
runway	O
less	O
visibility	O
would	O
be	O
required	O
to	O
see	O
sufficient	O
cues	O
to	O
confirm	O
the	O
aircraft	O
position	O
and	O
trajectory	O
.	O
</s>
<s>
With	O
an	O
angular	O
signal	O
system	O
such	O
as	O
ILS	O
,	O
as	O
altitude	B-Application
decreases	O
all	O
tolerances	O
must	O
be	O
decreased	O
–	O
in	O
both	O
the	O
aircraft	O
system	O
and	O
the	O
input	O
signal	O
–	O
to	O
maintain	O
the	O
required	O
degree	O
of	O
safety	O
.	O
</s>
<s>
It	O
will	O
be	O
possible	O
if	O
initiated	O
at	O
300	O
feet	O
of	O
height	B-Application
,	O
but	O
not	O
at	O
100	O
feet	O
.	O
</s>
<s>
Consequently	O
,	O
only	O
a	O
smaller	O
course	O
correction	O
can	O
be	O
tolerated	O
at	O
the	O
lower	O
height	B-Application
,	O
and	O
the	O
system	O
needs	O
to	O
be	O
more	O
accurate	O
.	O
</s>
<s>
Thus	O
,	O
while	O
an	O
aircraft	O
may	O
be	O
equipped	O
with	O
an	O
autoland	B-Device
system	O
,	O
it	O
will	O
be	O
totally	O
unusable	O
without	O
the	O
appropriate	O
ground	O
environment	O
.	O
</s>
<s>
The	O
result	O
of	O
all	O
this	O
is	O
to	O
create	O
a	O
spectrum	O
of	O
low	O
visibility	O
equipment	O
,	O
in	O
which	O
an	O
aircraft	O
's	O
autoland	B-Device
autopilot	O
is	O
just	O
one	O
component	O
.	O
</s>
<s>
only	O
(	O
Cat	O
I	O
)	O
,	O
and	O
similarly	O
no	O
autopilot	O
was	O
suitable	O
for	O
or	O
approved	O
for	O
use	O
below	O
this	O
height	B-Application
.	O
</s>
<s>
The	O
lateral	O
guidance	O
from	O
the	O
ILS	O
localizer	O
would	O
however	O
be	O
usable	O
right	O
to	O
the	O
end	O
of	O
the	O
landing	O
roll	O
,	O
and	O
hence	O
is	O
used	O
to	O
feed	O
the	O
rudder	B-Protocol
channel	O
of	O
the	O
autopilot	O
after	O
touchdown	O
.	O
</s>
<s>
As	O
aircraft	O
approached	O
the	O
transmitter	O
its	O
speed	O
is	O
obviously	O
reducing	O
and	O
rudder	B-Protocol
effectiveness	O
diminishes	O
,	O
compensating	O
to	O
some	O
extent	O
for	O
the	O
increased	O
sensitivity	O
of	O
the	O
transmitted	O
signal	O
.	O
</s>
<s>
In	O
short	O
,	O
very	O
low	O
visibility	O
operations	O
such	O
as	O
autoland	B-Device
can	O
only	O
be	O
conducted	O
when	O
aircraft	O
,	O
crews	O
,	O
ground	O
equipment	O
and	O
air	O
and	O
ground	O
traffic	O
control	O
all	O
comply	O
with	O
more	O
stringent	O
requirements	O
than	O
normal	O
.	O
</s>
<s>
The	O
first	O
"	O
commercial	O
development	O
"	O
automatic	B-Device
landings	I-Device
(	O
as	O
opposed	O
to	O
pure	O
experimentation	O
)	O
were	O
achieved	O
through	O
realizing	O
that	O
the	O
vertical	O
and	O
lateral	O
paths	O
had	O
different	O
rules	O
.	O
</s>
<s>
It	O
was	O
recognized	O
that	O
if	O
the	O
aircraft	O
had	O
arrived	O
at	O
decision	O
height	B-Application
(	O
200ft	O
)	O
on	O
a	O
correct	O
,	O
stable	O
approach	O
path	O
–	O
a	O
prerequisite	O
for	O
a	O
safe	O
landing	O
–	O
it	O
would	O
have	O
momentum	O
along	O
that	O
path	O
.	O
</s>
<s>
Consequently	O
,	O
the	O
autoland	B-Device
system	O
could	O
discard	O
the	O
glideslope	O
information	O
when	O
it	O
became	O
unreliable	O
(	O
i.e.	O
</s>
<s>
This	O
"	O
ballistic	B-Application
"	O
phase	O
would	O
end	O
at	O
the	O
height	B-Application
when	O
it	O
became	O
necessary	O
to	O
increase	O
pitch	O
and	O
reduce	O
power	O
to	O
enter	O
the	O
landing	O
flare	O
.	O
</s>
<s>
Autoland	B-Device
was	O
first	O
developed	O
in	O
BLEU	O
and	O
RAF	O
aircraft	O
such	O
as	O
the	O
English	O
Electric	O
Canberra	O
,	O
Vickers	O
Varsity	O
and	O
Avro	O
Vulcan	O
,	O
and	O
later	O
for	O
BEA	O
's	O
Trident	O
fleet	O
,	O
which	O
entered	O
service	O
in	O
the	O
early	O
1960s	O
.	O
</s>
<s>
It	O
had	O
an	O
autopilot	O
designed	O
to	O
provide	O
the	O
necessary	O
redundancy	O
to	O
tolerate	O
failures	O
during	O
autoland	B-Device
,	O
and	O
it	O
was	O
this	O
design	O
which	O
had	O
triple	O
redundancy	O
.	O
</s>
<s>
The	O
fail-safe	B-General_Concept
element	O
was	O
provided	O
by	O
a	O
"	O
voting	O
"	O
procedure	O
using	O
torque	O
switches	O
,	O
whereby	O
it	O
was	O
accepted	O
that	O
in	O
the	O
event	O
that	O
one	O
channel	O
differed	O
from	O
the	O
other	O
two	O
,	O
the	O
probability	O
of	O
two	O
similar	O
simultaneous	O
failures	O
could	O
be	O
discounted	O
and	O
the	O
two	O
channels	O
in	O
agreement	O
would	O
"	O
out-vote	O
"	O
and	O
disconnect	O
the	O
third	O
channel	O
.	O
</s>
<s>
In	O
these	O
operations	O
the	O
pilot	O
had	O
acquired	O
full	O
visual	O
reference	O
,	O
normally	O
well	O
above	O
decision	O
height	B-Application
,	O
but	O
instead	O
of	O
fully	O
disengaging	O
the	O
autopilot	O
with	O
the	O
thumb-button	O
,	O
called	O
for	O
the	O
second	O
officer	O
to	O
latch	O
off	O
the	O
roll	O
channel	O
only	O
.	O
</s>
<s>
As	O
the	O
accuracy	O
and	O
reliability	O
of	O
the	O
ground	O
based	O
ILS	O
localiser	O
was	O
increased	O
on	O
a	O
step	O
by	O
step	O
basis	O
,	O
it	O
was	O
permissible	O
to	O
leave	O
the	O
roll	O
channel	O
engaged	O
longer	O
and	O
longer	O
,	O
until	O
in	O
fact	O
the	O
aircraft	O
had	O
ceased	O
to	O
be	O
airborne	O
,	O
and	O
a	O
fully	O
automatic	B-Device
landing	I-Device
had	O
in	O
fact	O
been	O
completed	O
.	O
</s>
<s>
Subsequently	O
,	O
autoland	B-Device
systems	O
became	O
available	O
on	O
a	O
number	O
of	O
aircraft	O
types	O
but	O
the	O
primary	O
customers	O
were	O
those	O
mainly	O
European	O
airlines	O
whose	O
networks	O
were	O
severely	O
affected	O
by	O
radiation	O
fog	O
.	O
</s>
<s>
Early	O
autoland	B-Device
systems	O
needed	O
a	O
relatively	O
stable	O
air	O
mass	O
and	O
could	O
not	O
operate	O
in	O
conditions	O
of	O
turbulence	O
and	O
in	O
particular	O
gusty	O
crosswinds	O
.	O
</s>
<s>
The	O
result	O
was	O
that	O
on	O
the	O
whole	O
the	O
larger	O
new	O
airliners	O
were	O
now	O
able	O
to	O
absorb	O
the	O
costs	O
of	O
at	O
least	O
Category	O
2	O
autoland	B-Device
systems	O
into	O
their	O
basic	O
configuration	O
.	O
</s>
<s>
Simultaneously	O
,	O
pilot	O
organizations	O
globally	O
were	O
advocating	O
the	O
use	O
of	O
Head	B-Application
Up	I-Application
Display	I-Application
systems	O
primarily	O
from	O
a	O
safety	O
viewpoint	O
.	O
</s>
<s>
The	O
net	O
effect	O
was	O
pressure	O
within	O
the	O
industry	O
to	O
find	O
alternative	O
ways	O
to	O
achieve	O
low	O
visibility	O
operations	O
,	O
such	O
as	O
a	O
"	O
hybrid	O
"	O
system	O
which	O
used	O
a	O
relatively	O
low	O
reliability	O
autoland	B-Device
system	O
monitored	O
by	O
the	O
pilots	O
via	O
a	O
HUD	B-Application
.	O
</s>
<s>
A	O
major	O
problem	O
with	O
this	O
approach	O
was	O
that	O
European	O
authorities	O
were	O
very	O
reluctant	O
to	O
certificate	O
such	O
schemes	O
as	O
they	O
undermined	O
the	O
well-proven	O
concepts	O
of	O
"	O
pure	O
"	O
autoland	B-Device
systems	O
.	O
</s>
<s>
This	O
impasse	O
was	O
broken	O
when	O
British	O
Airways	O
became	O
involved	O
as	O
a	O
potential	O
customer	O
for	O
Bombardier	O
's	O
Regional	O
Jet	O
,	O
which	O
could	O
not	O
accommodate	O
a	O
full	O
Cat	O
3	O
autoland	B-Device
system	O
,	O
but	O
would	O
be	O
required	O
to	O
operate	O
in	O
those	O
conditions	O
.	O
</s>
<s>
This	O
airport	O
was	O
operating	O
at	O
maximum	O
capacity	O
in	O
good	O
conditions	O
,	O
and	O
the	O
imposition	O
of	O
low	O
visibility	O
procedures	O
required	O
to	O
protect	O
the	O
localizer	O
signal	O
for	O
autoland	B-Device
systems	O
meant	O
a	O
major	O
reduction	O
in	O
capacity	O
from	O
approximately	O
60	O
to	O
30	O
landings	O
per	O
hour	O
.	O
</s>
<s>
Since	O
most	O
airlines	O
operating	O
into	O
Heathrow	O
already	O
had	O
autoland-equipped	O
aircraft	O
,	O
and	O
thus	O
expected	O
to	O
operate	O
as	O
normal	O
,	O
massive	O
delays	O
occurred	O
.	O
</s>
<s>
Garmin	O
Aviation	O
started	O
studying	O
an	O
emergency	O
autoland	B-Device
feature	O
in	O
2001	O
and	O
launched	O
the	O
program	O
in	O
2010	O
with	O
more	O
than	O
100	O
employees	O
,	O
investing	O
around	O
$20	O
million	O
.	O
</s>
<s>
The	O
feature	O
is	O
activated	O
by	O
a	O
guarded	O
red	O
button	O
on	O
Garmin	O
G3000	O
avionics	O
,	O
evaluating	O
winds	O
,	O
weather	O
and	O
fuel	O
reserves	O
to	O
select	O
a	O
suitable	O
diversion	O
airport	O
and	O
taking	O
over	O
the	O
aircraft	O
controls	O
to	O
land	O
,	O
it	O
advises	O
the	O
ATC	B-Application
and	O
displays	O
instructions	O
to	O
occupants	O
.	O
</s>
<s>
In	O
June	O
2021	O
,	O
the	O
Garmin	O
Autoland	B-Device
system	O
won	O
the	O
2020	O
Collier	O
Trophy	O
,	O
for	O
"	O
the	O
greatest	O
achievement	O
in	O
aeronautics	O
or	O
astronautics	O
in	O
America	O
"	O
during	O
the	O
preceding	O
year	O
.	O
</s>
<s>
A	O
typical	O
autoland	B-Device
system	O
consists	O
of	O
an	O
ILS	O
(	O
integrated	O
glideslope	O
receiver	O
,	O
localizer	O
receiver	O
,	O
and	O
perhaps	O
GPS	O
receiver	O
as	O
well	O
)	O
radio	O
to	O
receive	O
the	O
localizer	O
and	O
glideslope	O
signals	O
.	O
</s>
<s>
At	O
the	O
appropriate	O
height	B-Application
above	O
the	O
ground	O
(	O
as	O
indicated	O
by	O
the	O
radio	O
altimeter	O
)	O
the	O
flight	O
control	O
computer	O
will	O
retard	O
the	O
throttles	O
and	O
initiate	O
a	O
pitch-up	O
maneuver	O
.	O
</s>
<s>
For	O
CAT	O
IIIc	O
,	O
the	O
flight	O
control	O
computer	O
will	O
continue	O
to	O
accept	O
deviations	O
from	O
the	O
localizer	O
and	O
use	O
the	O
rudder	B-Protocol
to	O
maintain	O
the	O
aircraft	O
on	O
the	O
localizer	O
(	O
which	O
is	O
aligned	O
with	O
the	O
runway	O
centerline	O
.	O
)	O
</s>
<s>
As	O
the	O
speed	O
decreases	O
,	O
the	O
rudder	B-Protocol
will	O
lose	O
effectiveness	O
and	O
the	O
pilot	O
will	O
need	O
to	O
control	O
the	O
direction	O
of	O
the	O
airplane	O
using	O
nose	O
wheel	O
steering	O
,	O
a	O
system	O
which	O
typically	O
is	O
not	O
connected	O
to	O
the	O
flight	O
control	O
computer	O
.	O
</s>
<s>
For	O
this	O
reason	O
autoland	B-Device
systems	O
are	O
designed	O
to	O
incorporate	O
a	O
high	O
degree	O
of	O
redundancy	O
so	O
that	O
a	O
single	O
failure	O
of	O
any	O
part	O
of	O
the	O
system	O
can	O
be	O
tolerated	O
(	O
fail	O
active	O
)	O
and	O
a	O
second	O
failure	O
can	O
be	O
detected	O
–	O
at	O
which	O
point	O
the	O
autoland	B-Device
system	O
will	O
turn	O
itself	O
off	O
(	O
uncouple	O
,	O
fail	O
passive	O
)	O
.	O
</s>
<s>
For	O
a	O
CAT	O
III	O
landing	O
,	O
all	O
the	O
sensors	O
and	O
all	O
the	O
flight	O
computers	O
must	O
be	O
in	O
good	O
health	O
before	O
the	O
pilot	O
receives	O
an	O
"	O
AUTOLAND	B-Device
ARM	O
"	O
indication	O
(	O
generic	O
indications	O
that	O
will	O
vary	O
depending	O
on	O
equipment	O
supplier	O
and	O
aircraft	O
manufacturer	O
)	O
.	O
</s>
<s>
If	O
the	O
system	O
is	O
properly	O
in	O
the	O
ARM	O
mode	O
,	O
when	O
the	O
ILS	O
receiver	O
detects	O
the	O
localizer	O
,	O
then	O
the	O
autoland	B-Device
system	O
mode	O
will	O
change	O
to	O
"	O
LOCALIZER	O
CAPTURE	O
"	O
.	O
</s>
<s>
At	O
this	O
point	O
the	O
autoland	B-Device
mode	O
will	O
change	O
to	O
CAT	O
III	O
and	O
the	O
aircraft	O
will	O
be	O
flown	O
by	O
the	O
flight	O
control	O
computer	O
along	O
the	O
localizer	O
and	O
glideslope	O
beams	O
.	O
</s>
<s>
If	O
the	O
autoland	B-Device
system	O
loses	O
redundancy	O
prior	O
to	O
the	O
decision	O
height	B-Application
,	O
then	O
an	O
"	O
AUTOLAND	B-Device
FAULT	O
"	O
error	O
message	O
will	O
be	O
displayed	O
to	O
the	O
flight	O
crew	O
at	O
which	O
point	O
the	O
crew	O
can	O
elect	O
to	O
continue	O
as	O
a	O
CAT	O
II	O
approach	O
or	O
if	O
this	O
is	O
not	O
possible	O
because	O
of	O
weather	O
conditions	O
,	O
then	O
the	O
crew	O
would	O
need	O
to	O
initiate	O
a	O
go-around	O
and	O
proceed	O
to	O
an	O
alternative	O
airport	O
.	O
</s>
<s>
If	O
a	O
single	O
failure	O
occurs	O
below	O
decision	O
height	B-Application
,	O
"	O
AUTOLAND	B-Device
FAULT	O
"	O
will	O
be	O
displayed	O
;	O
at	O
that	O
point	O
the	O
aircraft	O
is	O
committed	O
to	O
landing	O
and	O
the	O
autoland	B-Device
system	O
will	O
remain	O
engaged	O
,	O
controlling	O
the	O
aircraft	O
on	O
only	O
two	O
systems	O
until	O
the	O
pilot	O
completes	O
the	O
rollout	O
and	O
brings	O
the	O
aircraft	O
to	O
a	O
full	O
stop	O
on	O
the	O
runway	O
or	O
turns	O
off	O
the	O
runway	O
onto	O
a	O
taxiway	O
.	O
</s>
<s>
In	O
this	O
state	O
the	O
autoland	B-Device
system	O
is	O
"	O
one	O
fault	O
away	O
"	O
from	O
disengaging	O
so	O
the	O
"	O
AUTOLAND	B-Device
FAULT	O
"	O
indication	O
should	O
inform	O
the	O
flight	O
crew	O
to	O
monitor	O
the	O
system	O
behavior	O
very	O
carefully	O
and	O
be	O
ready	O
to	O
take	O
control	O
immediately	O
.	O
</s>
<s>
During	O
system	O
design	O
,	O
the	O
predicted	O
reliability	O
numbers	O
for	O
the	O
individual	O
equipment	O
which	O
makes	O
up	O
the	O
entire	O
autoland	B-Device
system	O
(	O
sensors	O
,	O
computers	O
,	O
controls	O
,	O
and	O
so	O
forth	O
)	O
are	O
combined	O
and	O
an	O
overall	O
probability	O
of	O
failure	O
is	O
calculated	O
.	O
</s>
