Raytheon's new AIM-9X Sidewinder air-to-air missile, now undergoing
final tests before being declared operational, could gain some
valuable new capabilities with the aid of new software to be tested
later this year. The new code will add a 'lock-on after launch'
(LOAL) mode to the missile. LOAL could allow the AIM-9X to be
launched at a beyond visual range (BVR) target, to engage a target
behind the launch airplane, and to be used more effectively from
the new Lockheed Martin F-35 Joint Strike Fighter.
LOAL has long been a controversial issue among fighter pilots.
As one pilot has commented: "It's like putting a pit bull
in a gunny sack, shaking him up and then opening the sack. He's
apt to bite the first thing he sees."
Raytheon director of business development Bill West counters that
"we do LOAL every day with AMRAAM"-Raytheon's radar-guided
AIM-120-and that LOAL will be used in conjunction with training
and tactics to reduce the risk of fratricide.
LOAL does not involve any changes to AIM-9X hardware, and works
in much the same way as on the AIM-120. The missile's inertial
navigation system steers it into a trajectory towards the target's
estimated position. The seeker activates and acquires the target
and the missile guides to impact.
There are three main potential applications of the technology,
West explains. The AIM-9X has lower drag than older AIM-9s and
has a longer range-sufficient to engage targets beyond the range
of its seeker. By using the fighter's radar to cue it in LOAL
mode, the AIM-9X can be used in a BVR engagement.
Another application of LOAL is to permit 360° engagements
in a networked environment. For example, one fighter in a group
can track a target that is behind his wingman and outside the
field of view of the wingman's radar. The target's location and
track can be datalinked to the wingman, allowing an accurate 'over
the shoulder' shot.
Finally, LOAL makes an important difference when it comes to integrating
the AIM-9X on the F-35. The only way to carry an AAM when the
JSF is in stealth mode, with internal weapons, is to carry it
on the inner weapons bay door. The missile's seeker has a very
restricted field of view in this position, making LOAL almost
essential. The UK plans to use the AIM-9X's rival, the MBDA ASRAAM,
from the JSF bay door, presumably in a LOAL mode.
So far, the U.S. Air Force and Navy have no stated requirement
for LOAL, says West, but a number of international customers have
shown interest in the concept. Switzerland, South Korea and Poland
have already selected the AIM-9X, and Raytheon is discussing sales
with Denmark, the Netherlands, Belgium, Portugal, Norway and Turkey.
More than 1,000 missiles are under contract and the AIM-9X is
due to reach initial operational capability (IOC) on U.S. Navy
F/A-18s and USAF F-15Cs later this year.
