Airbus Helicopters says it is testing a new architecture for its H135 twin-engine light helicopter after images emerged of one of the company’s aircraft in a new configuration.

Pictures taken from outside the company’s facility in Donauworth, Germany, and first published by the helicopter website Helihub on Sept. 22 show the aircraft in a similar configuration to the company’s Bluecopter environmental technology demonstrator. That aircraft was first flown in 2015.

The aircraft, registered D-HEEY, features a five-blade main rotor and replaces the H135’s four-blade configuration. It has a broader tail boom and a more swept vertical stabilizer, with a T-tail horizontal stabilizer sitting above the fenestron anti-torque system.  

The latter replaces the horizontal stabilizer set into the tail boom forward of the fenestron. The aircraft’s fuselage has also been updated with a more streamlined nose, fewer windows and larger clamshell doors at the rear.

Pictured unpainted, the aircraft also appears to make greater use of composite materials, which may suggest an effort to remove weight and increase payload capacity.

In an emailed response, an Airbus spokesman said the company was “testing new architectural elements. These include the five-bladed rotor that we successfully introduced on our H145 in 2019.”

It is unclear at this point whether the new configuration points to another environmental development aircraft or a new version of the 3-metric-ton H135 making use of the Bluecopter technology approach.  

H135 sales have in recent years begun to lag that of the larger H145 since it was upgraded with the five-blade main rotor and fenestron in 2019.

Around 1,400 H135s are in service around the world in more than 60 countries. The type is popular with law enforcement, emergency medical service operators and military customers for flight training missions.

The Bluecopter project was aimed at making helicopters more socially acceptable by reducing noise and fuel consumption. Self-funded by Airbus, it was also supported by Germany’s LuFo-IV research program and the European Clean Sky initiative.