The General Electric H80 is a turboprop aircraft engine produced by GE BGA Turboprops. Gas turbine engines are often categorised into turbojets, turbofans, turboprops and turboshafts. Nearly all modern airliners are now powered by turbine engines, either turbofans or turboprops. Bandeirante turboprops and Cessna 402 prop aircraft. Jet cards offering turboprops and piston aircraft instead of jets are increasing. Rolls-Royce Avon turbojets replacing the pair of turboprops. These are two jets and two turboprops. DHC-6 Twin Otter turboprops as well as Douglas DC-3 prop aircraft. Early small jets had higher operating costs than turboprops on short routes. Propeller systems, such as turboprops and propfans are a more fuel efficient technology than jets. The standard engines offered were two TPE331-3UW turboprops driving three-bladed propellers. The generally higher speeds and tensile stresses of turboprops and jets were major challenges. By 2018, 328 Support Services supported 200 turboprops and jets. Boeing responded with two models powered by T35 turboprops. Propfans are a more fuel-efficient technology than jet engines or turboprops.