[2] Another feature which became apparent upon entering service was the low noise levels produced, in part due to its Fenestron tail, the EC135 was the quietest aircraft in its class for more than 15 years.

[6] In 2014, Airbus Helicopters began flying the Bluecopter demonstrator aircraft, built to explore more efficient design elements, including economy-optimised single-engine operations, Blue Edge swept rotor blades to reduce noise and increase efficiency, a relocated horizontal stabilizer outside the main rotor's downwash, an active rudder, and new water-based external paint; these changes were aimed at cutting fuel consumption by 40%.

[7] In December 2014, the single-engine operations portion of the Bluecopter tests were delayed to summer 2016 to make necessary avionics changes, such as to the engine's FADEC systems.

It features a customized luxury four-place main cabin, a sliding glass partition, a corporate baggage hold, redesigned skid landing gear and other external changes.

The launch customer for the type is Falcon Aviation Services (FAS), based in Abu Dhabi, United Arab Emirates.

[10] In 2011, Eurocopter formalised a license manufacturing agreement with Zhong-Ou International Group to produce the EC135 luxury helicopter in Zhejiang Province, China.

[11] In October 2015, a letter of intent between Airbus Helicopters and Ecopark was signed for the establishment of a final assembly line (FAL) in Qingdao Province, China.

[15] In January 2016, the Ural Works of Civil Aviation (UWCA), a division of Rostec, signed an agreement to build the H135 under licence at the firm's facility in Yekaterinburg, Russia.

The modified cockpit allows customers to choose whether to remove the copilot side of the instrument panel to increase the field of view or keep it to install specific STC equipment.

It can be alternatively powered by a pair of Turbomeca Arrius 2B or Pratt & Whitney Canada PW206B engines, dependent on customer's preference, which gives either a T or a P, respectively, in the variant name.

[19] The EC135 is the quietest helicopter in its class, featuring an anti-resonance isolation system to dampen vibration from the main rotor.

[5] The type's Fenestron anti-torque device can be actively regulated via a HI NR rotor optimization mode, which provides for greater controllability during higher weight take-off and landings.

[25] Earlier versions of the EC135 were equipped with a three-axis autopilot with integrated stability augmentation,[2] featuring a First Limit Indicator (FLI), simplifying engine and torque monitoring.

[26] Medical facilities can be installed in the cabin, such as in-flight intensive care stations (including resuscitation functionality), incubators, and hygiene-convenient flooring.

[19] Airbus Helicopters has promoted the airframe's various configurations as possessing "unique adaptability" for various missions, including utility work, commercial transportation, and training roles.

[21] Equipment for the law enforcement role include external loudspeakers, rappelling system, search lights with laser pointers, left or right-mounted hoists, and electro-optical sensors.

[21] Deliveries started in August 1996, when two helicopters, 0005 and 0006, were handed over to German emergency aero medical service provider Deutsche Rettungsflugwacht.

The 100th EC135 was handed over to the Bavarian police force in June 1999, by which point the worldwide fleet had accumulated approximately 30,000 flight hours.

Originally delivered to the North East Air Support Unit in April 1999, it was the first EC135 worldwide to attain 10,000 flying hours.

[35] In 2013, it was reported that the EC135 was currently providing roughly 25% of the world's total emergency medic services flights, and that over 500 EC135s have been delivered to in an aeromedical configuration.

[36] By late 2013, during which a brief grounding of the type was instigated due to safety concerns of fuel gauges, the EC135 made up half of the UK's operational air ambulance fleet.

[41] In December 2014, the first production EC135 T3 entered service with Aiut Alpin Dolomites, a mountain rescue operator based in Italy.