Airbus Helicopters EC-135 now H135

A mostly aluminium airframe with composite parts where they save weight: control surfaces, fairings, the tail or the rotor blades. Largely composite fuselage shells. The design is held under 1 type certificate (H88EU, held by Airbus Helicopters Deutschland GMBH (Ahd)). The FAA has issued 79 airworthiness directives (orders that owners must comply with) that name this model, most of them about rotorcraft systems. Operators and repair shops have filed 1,518 failure reports with the FAA since 1998, 543 of them in the last ten years: about 13.7 a year for every 100 aircraft on the register; the system most often named is rotorcraft systems. 126 approved modifications exist for it, the most by Air Methods Corporation.

Sources: the FAA's type certificate data sheets, airworthiness directives, supplemental type certificates, special conditions and special airworthiness information bulletins (Dynamic Regulatory System), and the FAA's service difficulty reports. A failure report is what an operator or repair station chose to file; the counts show reporting as much as reliability, and larger and commercial fleets report more. How the systems are grouped.