Diamond Aircraft DA 42 Twin Star

The airframe is composite: carbon fibre or glass fibre set in resin, moulded in large pieces with few joints, which gives smooth shapes but needs different inspection and repair methods from metal. The design is held under 1 type certificate (A57CE, held by Diamond Aircraft Industries GMBH). The FAA has issued 27 airworthiness directives (orders that owners must comply with) that name this model, most of them about landing gear. Operators and repair shops have filed 313 failure reports with the FAA since 2007, 152 of them in the last ten years: about 5.7 a year for every 100 aircraft on the register; the system most often named is engine. 39 approved modifications exist for it, the most by Avidyne 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.