<s>
The	O
AN/APG	B-Device
-81	I-Device
is	O
an	O
active	B-Architecture
electronically	I-Architecture
scanned	I-Architecture
array	I-Architecture
(	O
AESA	O
)	O
radar	B-Application
system	I-Application
designed	O
by	O
Northrop	O
Grumman	O
Electronic	O
Systems	O
for	O
the	O
Lockheed	O
Martin	O
F-35	O
Lightning	O
II	O
.	O
</s>
<s>
The	O
Joint	B-Application
Strike	I-Application
Fighter	I-Application
AN/APG	B-Device
-81	I-Device
AESA	B-Architecture
radar	I-Architecture
is	O
a	O
result	O
of	O
the	O
US	O
government	O
's	O
competition	O
for	O
the	O
world	O
's	O
largest	O
AESA	O
acquisition	O
contract	O
.	O
</s>
<s>
Lockheed	O
Martin	O
and	O
Northrop	O
Grumman	O
were	O
selected	O
as	O
the	O
winners	O
of	O
the	O
Joint	B-Application
Strike	I-Application
Fighter	I-Application
competition	O
;	O
The	O
System	O
Development	O
and	O
Demonstration	O
(	O
SDD	O
)	O
contract	O
was	O
announced	O
on	O
26	O
October	O
2001	O
.	O
</s>
<s>
The	O
AN/APG	B-Device
-81	I-Device
is	O
a	O
successor	O
radar	B-Application
to	O
the	O
F-22	B-Application
'	I-Application
s	I-Application
AN/APG	B-Algorithm
-77	I-Algorithm
.	O
</s>
<s>
Over	O
three	O
thousand	O
AN/APG	B-Device
-81	I-Device
AESA	B-Architecture
radars	I-Architecture
are	O
expected	O
to	O
be	O
ordered	O
for	O
the	O
F-35	O
,	O
with	O
production	O
to	O
run	O
beyond	O
2035	O
,	O
and	O
including	O
large	O
quantities	O
of	O
international	O
orders	O
.	O
</s>
<s>
Capabilities	O
of	O
the	O
AN/APG	B-Device
-81	I-Device
include	O
the	O
AN/APG	B-Algorithm
-77	I-Algorithm
'	O
s	O
air-to-air	O
modes	O
,	O
plus	O
advanced	O
air-to-ground	O
modes	O
,	O
including	O
high	O
resolution	B-Application
mapping	I-Application
,	O
multiple	O
ground	O
moving	O
target	O
indication	O
and	O
track	O
,	O
combat	O
identification	O
,	O
electronic	O
warfare	O
,	O
and	O
ultra	O
high	O
bandwidth	O
communications	O
.	O
</s>
<s>
The	O
current	O
F-22	O
production	O
radar	B-Application
is	O
the	O
APG-77v1	O
,	O
which	O
draws	O
heavily	O
on	O
APG-81	B-Device
hardware	O
and	O
software	O
for	O
its	O
advanced	O
air-to-ground	O
capabilities	O
.	O
</s>
<s>
In	O
August	O
2005	O
,	O
the	O
APG-81	B-Device
radar	B-Application
was	O
flown	O
for	O
the	O
first	O
time	O
aboard	O
Northrop	O
Grumman	O
's	O
BAC	O
1	O
–	O
11	O
test	O
aircraft	O
.	O
</s>
<s>
The	O
radar	B-Application
system	I-Application
had	O
accumulated	O
over	O
300	O
flight	O
hours	O
by	O
2010	O
.	O
</s>
<s>
The	O
first	O
radar	B-Application
flight	O
on	O
Lockheed	O
Martin	O
's	O
CATBird	O
avionics	O
test-bed	O
occurred	O
in	O
November	O
2008	O
.	O
</s>
<s>
In	O
June	O
2009	O
,	O
the	O
F-35s	O
APG-81	B-Device
active	B-Architecture
electronically	I-Architecture
scanned	I-Architecture
array	I-Architecture
radar	B-Application
was	O
integrated	O
in	O
the	O
Northern	O
Edge	O
2009	O
large-scale	O
military	O
exercise	O
when	O
it	O
was	O
mounted	O
on	O
the	O
front	O
of	O
a	O
Northrop	O
Grumman	O
test	O
aircraft	O
.	O
</s>
<s>
The	O
test	O
events	O
"	O
validated	O
years	O
of	O
laboratory	O
testing	O
versus	O
a	O
wide	O
array	O
of	O
threat	O
systems	O
,	O
showcasing	O
the	O
extremely	O
robust	O
electronic	O
warfare	O
capabilities	O
of	O
the	O
world	O
's	O
most	O
advanced	O
fighter	O
fire-control	O
radar.	O
"	O
</s>
<s>
Announced	O
on	O
22	O
June	O
2010	O
:	O
The	O
radar	B-Application
met	O
and	O
exceeded	O
its	O
performance	O
objectives	O
successfully	O
tracking	O
long-range	O
targets	O
as	O
part	O
of	O
the	O
first	O
mission	O
systems	O
test	O
flights	O
of	O
the	O
F-35	O
Lightning	O
II	O
BF-4	O
aircraft	O
.	O
</s>
<s>
The	O
AN/APG	B-Device
-81	I-Device
team	O
won	O
the	O
2010	O
David	O
Packard	O
Excellence	O
in	O
Acquisition	O
Award	O
for	O
performance	O
against	O
jammers	O
.	O
</s>
<s>
In	O
January	O
2023	O
it	O
was	O
reported	O
that	O
the	O
AN/APG	B-Device
-81	I-Device
would	O
be	O
replaced	O
by	O
a	O
new	O
radar	B-Application
,	O
the	O
AN/APG	O
-85	O
on	O
Block	O
4	O
F-35s	O
.	O
</s>
