Country of origin
Range of fire
The first generation of AIM-9 Sidewinders had delivered mixed
results in combat over Southeast Asia. While they were the most
effective missile by far used by the US military in that theater,
the short range and narrow azimuth of their seeker heads gave them
much less utility than expected, and when stronger heat sources than
the target entered their field of view (e.g., burning vehicles on
the ground, factory smokestacks, and sun glare), Sidewinders would
go after these instead. The Probability of Kill (pK) ratio was also
far less than predicted, with Sidewinder launches only hitting
targets 25% of the time in the most favorable reports (on average,
the pK ratio of all Vietnam War Sidewinder launches combined was
10%) --- far from the promised 90%.
generation of the
Raytheon AIM-9 Sidewinder missiles was created based on analyses
of air combat reports in the Vietnam War. These missiles were the mainstay of many air arms
around the world for over 30 years. The AIM-9G Sidewinder was a new missile based on the overall design of
the AIM-9D, but with an improved seeker head. It was developed for
the US Navy. It was adopted by the US Navy in 1970.
The AIM-9G differ from the AIM-9D in having a slightly longer
fuselage and a slightly shorter and more conical nosecone, and
slightly larger forward fins, though several components are
different. Few alterations were made to the AIM-9G's construction
over the AIM-9D, with the only notable change being a new seeker
head. The general composition of the AIM-9G Sidewinders is largely the
same as of previous Sidewinder missiles.
The guidance system used in the AIM-9G introduced a steerable seeker head that
allowed for engagement of off-boresight targets, referred-to as the
Sidewinder Extended Acquisition Mode (SEAM) system.
A precursor to
today's "all-aspect" guidance systems, SEAM allowed an aircraft
launching the AIM-9G to attack targets that were generally in
front of it, rather than literally having to point the missile
itself directly at the target to achieve a lock. This significantly
increased the usefulness of the Sidewinder, as obtaining a lock was
much less difficult under these circumstances. SEAM also enabled the
Sidewinder to be slaved onto a target before the missile even left
the rail, greatly improving it's odds of destroying the target. The
AIM-9G was still a "tail-chaser" however. It could
only lock onto a jet aircraft from behind.
AIM-9G uses the same motor as other second generation Sidewinder
missiles. It accelerates the missile to a
speed of approximately Mach 2.5, within seconds after launch, by
which time the propellant has already been expended.
The AIM-9G uses the same warhead as the previous AIM-9D - the Mk.48
continuous rod warhead. It was powerful enough that a single Sidewinder
could potentially shoot-down any aircraft with a single direct hit.
It is unclear how many AIM-9G Sidewinders were ever produced.
Different sources have produced different claims and there is a
strong disagreement on production figures. Figures vary from 2 120
to 20 000 units, depending on the source.
As with the AIM-9B Sidewinder, the
second generation of Sidewinder missiles, including the -E, -F, -G, and
-H models were
very long-lived in operational service. Exactly how long they've
remained in service is unclear, through given that some air arms
still use the AIM-9B, some of these four newer missiles are probably
still operational as well.
The AIM-9G were all rebuilt by Philco-Ford
Aerospace, with considerable assistance from Raytheon. Production of
the AIM-9G ended by the
mid-1970s, and any remaining serviceable examples are nearing their
expiration dates. They are no longer available for production, and
assuming any of them are still available for export, they are
probably only worth their scrap value.
The AIM-9G arrived in time to see some combat use over
Southeast Asia. Relatively few were launched, achieving 14 kills.
ATM-9G Sidewinder: Captive air training version of the
AIM-9G. It has ballasts in place of the engine and warhead, and is
used in training exercises to lock-onto other aircraft in mock
AIM-9H Sidewinder: This is basically an AIM-9G with
substantial reliability improvements. The AIM-9H
introduced solid state electronics, an improved warhead, and a
thermal battery (which replaced the turbo-alternator used in the
AIM-9D). The AIM-9H was
also given an improved motor, made by Hercules Bermite,
in the form of the Mk.36 Mod 5,6, or 7 (depending on which phase of
production a given AIM-9H was built in). An improved version of the
Mk.48 Continuous Rod is installed in the AIM-9H. This missile has a
virtually identical exterior to that of the AIM-9G. It entered service with the US Navy in 1972.
ATM-9H Sidewinder: These are basically ATM-9Gs upgraded to
carry the seeker head of the AIM-9H.
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