An airborne laser weapon dubbed the long-range blowtorch" has the added benefit that the US could convincingly deny any involvement with the destruction it causes, say senior officials of the US Air Force (USAF). The Advanced Tactical Laser (ATL) is to be mounted on a Hercules military transport plane. Boeing announced the first test firing of the laser, from a plane on the ground, earlier this summer. Cynthia Kaiser, chief engineer of the US Air Force Research Laboratory's Directed Energy Directorate, used the phrase "plausible deniability" to describe the weapon's benefits in a briefing ... on laser weapons to the New Mexico Optics Industry Association in June. As the term suggests, "plausible deniability" is used to describe situations where those responsible for an event could plausibly claim to have had no involvement in it. John Pike, analyst with defence think-tank Global Security, based in Virginia, says the implications are clear. "The target would never know what hit them," says Pike. "Further, there would be no munition fragments that could be used to identify the source of the strike." A laser beam is silent and invisible. An ATL can deliver the heat of a blowtorch with a range of 20 kilometres, depending on conditions. That range is great enough that the aircraft carrying it might not be seen, especially at night. With no previous examples for comparison, it may be difficult to discern whether damage to a vehicle or person was the result of a laser strike.