Vertiflite May/June 2021

A/S, CHC Helicopter and Noordzee Helikopters Vlaanderen (NHV), and is home of Bel Air Aviation, which was the launch customer for the AW189. The AW189 also went further north to Brønnøysund, Norway. In March 2016, the aircraft went back to Esbjerg for further testing and then to Gothenburg, Sweden. In the North Sea, there are similar adverse conditions throughout the autumn and winter months. However, unlike the US, where the ideal conditions for ice conditions are over, around Scandinavia, the best conditions are found over the sea, with the added advantage that air temperatures over water are layered, meaning an aircraft can move up or down in altitude to find All in all, the success of the HISS and cold weather trials in the coldest regions of the globe have supported LIPS and FIPS certifications for Leonardo’s AW139 medium twin and AW189 super medium. Meanwhile, the AW169 had completed the first of two series of HISS trials in the US Great Lakes region in February 2020 when the global coronavirus crisis began.Unfortunately, the teamfromLeonardohad to leave the test aircraft in the US and return to Italy immediately.As it stands, with global vaccination programs and changing numbers of infections, it is still unclear when the team will be able to return to complete their tests, though they are hopeful they will be able to continue at some point later this year. Once certificated, Rega will be the first customer for the FIPS-equipped AW169. However, it is not just offshore or the parapublic customers operating in adverse conditions that require FIPS and LIPS. Maybe surprisingly, the private and corporate marketplaces have also shown enthusiasm for the ice protection innovations — enabling them to fly fromA to B, even in bad conditions without the need to wait or delay and giving them a highly valued flexibility. Sikorsky equipped its 26,500-lb (12-t) S-92 with its rotor ice protection system (RIPS), based on its S-70/H-60 Black Hawk family (with many thousands of aircraft in service). This is also a selling point for its AW609 tiltrotor: “Capable of flying at 25,000 ft [7.6 km] and into known icing conditions, the AW609 won’t let bad weather ruin your travel plans.” Shortly after its initial flight checkouts, the third AW609 prototype began icing tests with the HISS in 2017 in northern Michigan for Leonardo’s civil tiltrotor certification. Soon, Leonardo will have a civil product range with the AW169 light intermediate twin, AW139 medium twin, AW189 super medium twin and AW609 tiltrotor with full ice protection. About the Author Ian Frain runs an aviation research consultancy in Cambridge, United Kingdom, called Helian, and also has a base in Austria/ Germany. He has a BSc in Engineering —Aerospace and Mechanical — from University of Hertfordshire, and has worked in both offshore and parapublic helicopter maintenance, and as a researcher in an aviation publishing company. He can be reached at ian@helianinternational.com . cooler to warmer conditions. Mountains to Overcome

Rega plans to supplement its AW109SP Da Vinci light twins with AW169 light intermediate twins when they are FIPS-certified. (Leonardo)

so tests are also carried out in natural icing conditions, but the specific conditions needed are often difficult to find and may delay certification by months. Under the HISS assessment test results, the parameters looked at include any increase in vibration during deicing, whether there were any changes in the behavior of the engine due to ice ingestion, and if there were any indications of SLD recognition and escape. Over the years, Leonardo has carried out HISS tests with the CH-149 Cormorant (AW101) SAR helicopters flown by the Royal Canadian Air Force, with its FIPS for military certification during 2003, and again in 2009 for its new tail rotor configuration. In the civilian marketplace, the AW139 with LIPS was tested during 2007 and with FIPS in 2008 — it received FIPS certification by the European Aviation Safety Agency (now the European Union Aviation Safety Agency) in 2010. The larger AW189 was tested in 2014 with LIPS and 2015 with FIPS. After three years of cold weather trials around northern Europe and in North America, EASA certificated the AW189 FIPS in July 2016 (following LIPS certification in September 2015). Alaskan and Nordic Adventures Fairbanks, Alaska, is the coldest city in the United States, with average temperatures ranging from 14 to -16°F (-10 to -26 °C) during November to February — but that’s too cold and too dry to successfully test the LIPS and FIPS systems. Therefore, the cold weather trials were carried out on the AW139 in September/ October 2008 and again in September/October 2009, when the weather conditions included the necessary humidity to create the required testing conditions. The second AW189 prototype went to Fairbanks in 2015 for cold weather trials. Another advantage to the area is its remoteness (meaning the company didn’t have difficulty finding clear airspace in which to fly) and the stability of its weather conditions. According to Bellussi, other cold weather trials took place in Scandinavia for both airframes, starting with the AW139 in Tirstrup, Denmark, in February and March 2012. The second AW189 prototype went to Esbjerg Airport during March 2015, which is the long-time base for Danish offshore operations. The airport has been a base for the former Maersk Helicopter Service

May / June 2021

34