September 03, 2012
Credit: Credit: Australian Defense Department
Bradley Perrett Canberra
A fighter costs tens of millions of dollars, at least. A stand-off missile to keep it and its crew safe from air defenses can cost hundreds of thousands. But a wing kit and guidance package, converting a bomb into a guided glide weapon that might do the same job, probably costs only tens of thousands.
Creating such a weapon by mating a range-extending wing to the Boeing Joint Direct Attack Munition (JDAM) guidance unit is such an obvious idea it is surprising that the concept is only now going into production, as JDAM-ER (extended range). Boeing says it aims to begin deliveries of an Australian-developed wing kit in 2015, with the Royal Australian Air Force (RAAF) as the first user.
The range of JDAM-ER is classified and depends on the launch conditions and commanded trajectory, but data from a predecessor program suggests that 110 km (60 nm) from high altitude is likely, presenting a considerable challenge to air defenses. Stand-off weapons are already hard to handle, but what if the enemy has 10 times as many?
Glide bombs have well-known limitations, however. The launch aircraft must expose itself by flying high if the bomb is to go far, and the weapon's sedate gliding speed gives alert defenders a long time for reaction. Historically, a further problem for such weapons has been the high cost of the guidance system, but that changed in the 1990s with the arrival of the mass-produced JDAM unit using GPS and inertial data.
Despite its obviously wide applications, the JDAM-ER program has received little attention. Its existence has not been secret—indeed, it roots go back to an Australian development effort that began in the 1980s—but until now the Australians and Boeing have said little about it.
Australia contracted Boeing last year to build and integrate the wing kits based on a design by the Australian defense department's Defense Science & Technology Organization, which also took part in further development. Boeing is working with local manufacturers to initiate production.