Schweizer SGS 1 gliders (1-26, 1-34, 1-35, 1-36)

The airframe is aluminium: sheet metal over a riveted frame, the way most aircraft have been built since the 1940s. The 1-26 has a fabric-covered aft fuselage on early examples. The design is held under 5 type certificates. The FAA has issued 3 airworthiness directives (orders that owners must comply with) that name this model, most of them about other and general. Operators and repair shops have filed 1 failure report with the FAA since 2019, 1 of them in the last ten years: about 0.2 a year for every 100 aircraft on the register; the system most often named is instruments and avionics. 12 approved modifications exist for it, the most by Ceconite INC.

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.