<s>
A	O
tail	B-Device
warning	I-Device
radar	I-Device
,	O
sometimes	O
TW	O
for	O
short	O
,	O
was	O
a	O
short-lived	O
class	O
of	O
aircraft-mounted	O
radar	B-Application
systems	I-Application
used	O
to	O
provide	O
warning	O
of	O
another	O
aircraft	O
approaching	O
from	O
the	O
rear	O
.	O
</s>
<s>
They	O
were	O
mostly	O
used	O
on	O
World	O
War	O
II	O
bombers	B-Application
,	O
starting	O
with	O
the	O
Monica	O
system	O
fit	O
to	O
Royal	O
Air	O
Force	O
(	O
RAF	O
)	O
heavy	O
bombers	B-Application
starting	O
in	O
June	O
1942	O
.	O
</s>
<s>
These	O
had	O
to	O
be	O
withdrawn	O
over	O
Europe	O
in	O
1944	O
when	O
it	O
was	O
learned	O
the	O
Luftwaffe	O
was	O
homing	O
in	O
on	O
their	O
signals	O
using	O
the	O
Flensburg	O
radar	B-Application
detector	O
.	O
</s>
<s>
A	O
small	O
number	O
were	O
then	O
transferred	O
to	O
RAF	O
de	O
Havilland	O
Mosquito	O
night	O
fighters	O
to	O
attract	O
the	O
German	O
fighters	O
,	O
and	O
when	O
one	O
was	O
seen	O
approaching	O
the	O
Mosquito	O
would	O
perform	O
a	O
controlled	O
360	O
degree	O
turn	O
that	O
would	O
result	O
in	O
the	O
German	O
aircraft	O
in	O
front	O
of	O
the	O
Mosquito	O
and	O
centered	O
in	O
their	O
radar	B-Application
.	O
</s>
<s>
During	O
the	O
same	O
time	O
,	O
the	O
Luftwaffe	O
began	O
adding	O
additional	O
rearward-pointing	O
antennas	O
to	O
their	O
night	O
fighters	O
as	O
an	O
ad-hoc	O
tail	B-Device
warning	I-Device
radar	I-Device
to	O
provide	O
some	O
protection	O
from	O
these	O
dreaded	O
"	O
Serrate	O
"	O
intruder	O
flights	O
.	O
</s>
<s>
Dedicated	O
tail	B-Device
warning	I-Device
radars	I-Device
were	O
used	O
for	O
a	O
relatively	O
short	O
time	O
,	O
from	O
late-WWII	O
through	O
the	O
1950s	O
.	O
</s>
<s>
One	O
of	O
the	O
last	O
major	O
uses	O
was	O
the	O
Red	O
Steer	O
system	O
on	O
the	O
V	O
bombers	B-Application
,	O
a	O
long-range	O
system	O
that	O
was	O
used	O
to	O
help	O
the	O
electronics	O
warfare	O
officer	O
properly	O
time	O
the	O
use	O
of	O
jammers	O
and	O
chaff	O
.	O
</s>
<s>
Today	O
,	O
similar	O
tasks	O
are	O
generally	O
provided	O
by	O
passive	O
receiver	O
systems	O
that	O
listen	O
for	O
the	O
signals	O
from	O
the	O
interceptor	O
aircraft	O
's	O
radars	B-Application
;	O
such	O
systems	O
do	O
not	O
provide	O
range	O
information	O
but	O
are	O
still	O
useful	O
while	O
not	O
giving	O
off	O
any	O
signals	O
of	O
their	O
own	O
.	O
</s>
<s>
These	O
systems	O
also	O
have	O
the	O
advantage	O
of	O
working	O
against	O
air	O
and	O
ground	O
radars	B-Application
,	O
which	O
became	O
important	O
as	O
the	O
main	O
anti-aircraft	O
threat	O
moved	O
to	O
surface-to-air	O
missiles	O
(	O
SAMs	O
)	O
.	O
</s>
<s>
A	O
new	O
class	O
of	O
tail	B-Device
warning	I-Device
radars	I-Device
emerged	O
in	O
the	O
1980s	O
,	O
primarily	O
as	O
a	O
counter	O
to	O
SAM	O
fire	O
.	O
</s>
<s>
The	O
AN/ALQ	O
-153	O
was	O
used	O
on	O
the	O
Boeing	O
B-52	O
G	O
and	O
H	O
and	O
Rockwell	O
B-1B	O
aircraft	O
and	O
saw	O
action	O
during	O
the	O
Gulf	B-Application
War	I-Application
.	O
</s>
<s>
The	O
Automatic	O
Gun	O
Laying	O
Turret	O
used	O
on	O
Royal	O
Air	O
Force	O
Avro	O
Lancaster	O
bombers	B-Application
combined	O
tail	O
warning	O
with	O
gun	O
laying	O
.	O
</s>
<s>
Systems	O
like	O
these	O
were	O
found	O
on	O
many	O
post-war	O
bomber	B-Application
designs	O
and	O
are	O
generally	O
regarded	O
as	O
a	O
separate	O
class	O
.	O
</s>
