The Australian Transport Safety Bureau (ATSB) is warning of the shortcomings of night vision goggles (NVG) in civil helicopter operations and argues that a complete night vision imaging system (NVIS), including modified cockpit lighting, is required to improve the safety and effectiveness of NVGs. The ATSB's comments come as NVGs are being approved for civil helicopter operations around the world.

NVGs have the potential to improve the safety of visual flight at night, says the ATSB. They can provide pilots with a significant increase in the quality of visual information compared with unaided night vision. They allow pilots to see the horizon, objects, terrain and weather more easily and allow the pilot to maintain spatial orientation.

The bureau warns, however, that NVGs have inherent risks as they are monochromatic, have a limited field of view, a lower visual acuity and the quality of the image is variable. The major risk is that pilots can overestimate the capabilities of the technology and fly into inappropriate conditions.

The risks of NVGs can be mitigated by implementing an NVIS package, says the ATSB. In addition to NVGs, this includes helicopter modifications to ensure that cockpit lighting is compatible, other external lighting modifications, training for flight crew, operational procedures and airworthiness requirements.

The ATSB's study of NVGs comes as a number of countries have approved their use for civil helicopter operations. For example, in Switzerland the Swiss air rescue service Rega has been operating successfully with NVGs since the late 1980s; the US Federal Aviation Administration began approving NVG use on a case-by- case basis in the late 1990s; and a number of UK police helicopters are undertaking NVIS operations.


Source: Flight International