Eurocopter EC135

The Airbus Helicopters H135, originally known as the Eurocopter EC135, has a rich history that dates back to the 1970s. Its story began under the Messerschmitt-Bölkow-Blohm (MBB) banner with the Bo 108, a pioneering technology demonstrator developed in collaboration with Aérospatiale. The aim was to incorporate the robustness of the earlier MBB Bo 105 while exploring innovations like the first full-authority digital engine controls (FADEC), a hingeless main rotor, and an advanced transmission system. The initial Bo 108 prototype first took to the skies in October 1988, powered by Allison engines, and was later followed by a variant using Turbomeca TM319-1B Arrius engines. These early demonstrators, though featuring conventional tail rotors, laid the groundwork by proving that modern design and cutting-edge technology could be successfully merged in a helicopter.

In the early 1990s, the design evolved significantly, and with the formation of Eurocopter, the concept re-emerged as the EC135. This refreshed design boasted an aerodynamically optimized airframe, incorporating a Fenestron anti-torque tail rotor that replaced traditional tail rotors, advanced composite materials, and enhanced resonance isolation systems. In 1994, two pre-production prototypes were built, each tested with either Turbomeca Arrius or Pratt & Whitney Canada PW206B engines, showcasing impressive performance and fuel efficiency. The EC135 made its public debut at the Heli-Expo convention in Las Vegas in January 1995, where its sleek design, low-noise operation, and state-of-the-art technological features captured the attention of potential buyers and the aviation community alike.

Certification soon followed, with the EC135 gaining European JAA approval and subsequent FAA certification in 1996. Its operational credentials were further bolstered when Germany’s Luftfahrt-Bundesamt (LBA) granted it single-pilot IFR certification in December 1999, a milestone that was mirrored by the United Kingdom’s Civil Aviation Authority in December 2000. These endorsements, combined with its adaptability to various roles—from emergency medical services and law enforcement to corporate and offshore support—cemented the EC135’s reputation. By September 2020, the helicopter had become a global workhorse with over 1,400 units delivered to 300 operators in 60 countries, collectively amassing more than 5 million flight hours.

The evolution of the EC135 was marked by continuous innovation and refinement. In the early 2000s, new variants such as the EC135P2 and EC135T2 were introduced, featuring upgraded engines—the Pratt & Whitney Canada PW206B2 and Turbomeca Arrius 2B2 respectively—that enhanced performance, particularly in single-engine operations. Advancements in avionics led to the introduction of the Avionique Novelle glass cockpit, and later the Helionix suite, which offered a modern four-axis autopilot and improved flight control capabilities. Research projects like the EC135 active control technology demonstrator (ACT/FHS) and the Bluecopter program further pushed the boundaries of efficiency and noise reduction, promising reductions in fuel consumption and environmental impact.

The platform’s versatility is also reflected in its diverse range of variants. Early models like the EC135P1 and T1 were succeeded by enhanced versions such as the EC135P2+, EC135T2+, and later, the high-performance EC135P3 and H135T3 versions that offer increased maximum takeoff weights, extended mission capabilities, and improved high altitude and hover performance. The military variant, known as the H135M (or originally the EC635), caters to specialized roles such as fire support, medical evacuation, and flight training for armed forces. Beyond its technical marvels, the EC135 has also found its way into niche markets with exclusive editions like ‘L’Hélicoptère par Hermès’, a VIP model boasting luxurious interiors and bespoke design elements.