Abstract: A gas turbine engine includes a first flow passage and a main combustion arrangement in the first flow passage. The engine further includes a second flow passage and a first catalytic combustion arrangement in the second flow passage, wherein the second flow passage can communicate with the first flow passage at at least one upstream passage junction upstream of the main combustion arrangement and upstream of the first catalytic combustion arrangement, and the second flow passage can communicate with the first flow passage at at least one downstream passage junction downstream of the main combustion arrangement and downstream of the first catalytic combustion arrangement.

Abstract: An air propeller arrangement for propulsion of a fixed-wing aircraft includes a first air propeller that includes a first hub member and at least a first and a second propeller blade, the first and second blades being configured to contribute significantly to the propulsion and having a substantially equal length. Each of the blades has an inner, root end arranged at the first hub member and an outer, tip end positioned at a distance from the first hub member such that each blade extends in a radial direction from the first hub member. The first and second blades are interconnected at their outer ends. An aircraft provided with such an air propeller arrangement is also provided.

Abstract: An outlet device for a jet engine comprises a number of fixed ducts, each with a gas intake and a gas outlet for conducting a gas from the jet engine, at least two of the outlets of said gas ducts open in different directions, and a gas distribution arrangement is arranged at the gas intakes for selective distribution of the gas to the ducts.

Abstract: A gas turbine engine includes a first flow passage and a main combustion arrangement in the first flow passage. The engine further includes a second flow passage and a first catalytic combustion arrangement in the second flow passage, wherein the second flow passage can communicate with the first flow passage at at least one upstream passage junction upstream of the main combustion arrangement and upstream of the first catalytic combustion arrangement, and the second flow passage can communicate with the first flow passage at at least one downstream passage junction downstream of the main combustion arrangement and downstream of the first catalytic combustion arrangement.

Abstract: An outlet device for a jet engine comprises a number of fixed ducts, each with a gas intake and a gas outlet for conducting a gas from the jet engine, at least two of the outlets of said gas ducts open in different directions, and a gas distribution arrangement is arranged at the gas intakes for selective distribution of the gas to the ducts.