BAE Systems has unveiled a new technology that may allow rotary-wing pilots to detect and evade small arms fire.

The acoustic-based hostile fire indicator (HFI) is not yet operational, but the company has shown video of the system in action. This shows an MD Helicopters MD520 taking evasive action, presumably after detecting rounds fired within a few hundred feet by a "soldier" armed with an AK-47 rifle.

BAE says: "In live-fire tests in the United States, an HFI system measured acoustic data and accurately detected threats in each test case. Further testing on military aircraft, using additional sensing technologies and techniques, will make the system more robust and improve its detection capabilities."

A growing number of military helicopters are equipped with infrared-based sensors to detect missile attacks, but rotary-wing crews remain vulnerable to small arms.

The US Army began investigating acoustic-based sniper detection systems for helicopters in 2004, following a string of fatal attacks on helicopters in Afghanistan and Iraq. The service's interest is known to have also attracted interest from Lockheed Martin and Northrop Grumman, but no effective solution has publicly emerged.

It is not clear how far BAE has advanced its HFI technology, nor how soon it would be available for delivery. "Timing would depend on any future customer requirements," it says.

BAE acknowledges that filtering out background noise from the helicopter's rotor system remains the HFI's biggest technical challenge.


Source: Flight International