The use of NVGs in civil helicopters is still in its infancy, so obtaining approval for night operations, including those with night-vision goggles (NVGs), remains a lengthy and tricky process, according to European helicopter emergency medical service (HEMS) operators. During a conference at Helitech, a number of HEMS operators shared their experiences obtaining such approvals and discussed challenges that regulators should mediate to ease the burden on operators.
UK-based Bond Air Services gained approval to fly HEMS missions at night using NVGs in May, becoming the first operator to earn that distinction in the UK. Bond operates on behalf of the East Anglian Air Ambulance (EAAA) charity organization. The EAAA believes the approval will allow it to conduct approximately 30 percent more missions, helping an estimated 300 more patients a year. The charity decided to seek approval for night HEMS because its executives found it unacceptable that a victim of an accident happening at 6 p.m. in winter was less likely to survive than a victim at the same time of the day in summer.
To give an idea of how lengthy such an approval process can be, Bond head of flight operations Alex Stobo recounted his company’s experience. Bond won the tender in 2010. The helicopter, a Eurocopter EC135, was ordered in November 2011. One month later, the UK CAA sent a list of items to be addressed for night HEMS operations. Bond answered in January 2012. It took six months for the CAA to publish a safety directive detailing the conditions to be met. This was in July 2012, and the approval followed 10 months later.
The biggest issue, director of flight operations Pete Cummings remembered, was finding a light capable of illuminating any object below 500 feet. Separately, Bond found a way to add wire depiction on the moving map. A powerline detection system was fitted to the helicopter but Stobo warned that smaller lines might sometimes be masked by bigger, more powerful ones.
Spain’s Inaer began night operations in 2006 and today operates six of its 26 bases at night. “We use NVGs to maintain VFR conditions at night, which makes the operation compliant with Spanish rules,” said pilot Carlos de la Cruz. Nevertheless, he pointed out some limitations of operating with night-vision goggles. In addition to the narrower field of view, depth perception is reduced, the image is monochrome and quality varies with light, he said. Moreover, the extra weight on the pilot’s head contributes to fatigue–something that Harald Weber, a pilot with Germany’s DRF Luftrettung, confirmed.
Inaer has flown 1,470 night HEMS missions with its Eurocopter EC145s, accident-free so far except for a minor bird strike, de la Cruz said.
The DRF Luftrettung was approved for unrestricted NVG operations in 2009. Pilot Weber reports that the approval represents a significant improvement, in part because the helicopter crew no longer depends on ground personnel (police, firemen and so on) for lighting a landing area and the surrounding obstacles. However, the DRF policy still insists on the presence of ground personnel for landing-site lighting “for safety reasons and because currently not all bases use NVGs,” Weber explained.
Last year 22 percent of Norway’s Norsk Luftambulanse flights were conducted at night with NVGs. A certification problem prevented the operator from flying with NVGs for one year, manager of flight operations Erik Normann said. He asserts that Norway’s CAA did not give the operator temporary exemptions during the lengthy and costly EASA certification process and in essence handled “technical requirements in a manner that made things more dangerous.” Some other European CAAs issued such exemptions, he claimed.
The remaining issues relate to certification, too, according to Normann. He said that one modification invalidates the entire certification. Weber suggested the European Helicopter Association should lobby for swifter certification processes.
Finally, the idea of adding symbology to the NVG image was discussed. Display NVGs project selected symbology and allow the user to remain head up while monitoring aircraft systems, Stobo explained. De la Cruz and Stobo agreed this would be an improvement. For example, in snowy conditions, “you would see whether you are moving,” Stobo said. Cummings cautioned that EASA certification would be needed. “Regulation is behind technology,” he lamented.