H135M / EC365

The Airbus Helicopters H135 (formerly Eurocopter EC135) is a twin-engine light utility helicopter developed in Germany and produced by Airbus Helicopters. Entering service in 1996, the aircraft is used for emergency medical transport, law enforcement, offshore operations, corporate transport, and military flight training. A military derivative is designated as the H135M or EC635. By September 2020, 1,400 units had been delivered to operators across 60 countries, accumulating over 5 million flight hours.

Development

Development originated in the 1970s under Messerschmitt-Bölkow-Blohm (MBB) as the Bo 108 technology demonstrator, which first flew on 17 October 1988. Re-designated as the EC135 following the creation of Eurocopter, the design was revised to incorporate a Fenestron tail rotor and a hingeless main rotor, making its first flight in February 1994. European JAA certification was achieved in June 1996, followed by FAA approval in July 1996 and single-pilot instrument flight rules certification in December 1999. Primary assembly occurs at Donauwörth, Germany, with an additional final assembly line opened in Qingdao, China, in 2019 and a license agreement established in Yekaterinburg, Russia, in 2016.

Design

The H135 is a twin-engine rotorcraft featuring a four-bladed hingeless composite main rotor, an anti-resonance vibration isolation system, and a Fenestron shrouded tail rotor. Power is supplied by either two Turbomeca Arrius 2B or Pratt & Whitney Canada PW206B turboshaft engines, both managed by full-authority digital engine controls (FADEC). The flight deck can be configured with conventional instruments, the Thales-supplied Avionique Nouvelle glass cockpit, or the Helionix suite featuring a four-axis autopilot. The cabin is accessed via side doors or rear clamshell doors and can be outfitted for up to seven passengers, intensive care medical suites, or specialized mission equipment including electro-optical sensors, searchlights, and external cargo hooks rated up to 272 kg.

Operational History

Initial deliveries began in August 1996 to German emergency medical service provider Deutsche Rettungsflugwacht. Military operators include the German Army, which operates 19 H135 trainers at Bückeburg, the Japan Maritime Self-Defense Force with 13 TH-135 trainers, and the Royal Air Force with 29 Juno HT.1 training helicopters. The Australian Defence Force operates 15 EC135T2+ aircraft for pilot training alongside 5 H135T3 units leased from the UK Ministry of Defence in 2024, while the Iraqi Army Aviation Command operates 20 aircraft.

Variants

• EC135 P1: Powered by two 463 kW Pratt & Whitney Canada PW206B engines, this initial production model features a maximum takeoff weight of up to 2,835 kg.

• EC135 T1: Powered by two 435 kW Turbomeca Arrius 2B1 series engines, this initial variant shares the progressive weight upgrades of the P1.

• H135 (EC135 T3): Powered by two 492 kW Arrius 2B2Plus engines, this variant introduces wider main rotor blades, repositioned engine air intakes, and a maximum takeoff weight of 2,980 kg.

• EC635/H135M: Military variant designed for medical evacuation and fire support duties, operated by Jordan, Switzerland, and Iraq.

• TH-135: Military training variant developed from the EC135 T2+ for military flight instruction.