Advances in the development of radiation pyrometry for measuring the blade temperature in gas-turbine engines are reported. In this system, engine-mounted sensor heads collect thermal radiation from either a spot or a reasonably large area of the turbine blade. High-temperature fiber optics transmit the radiation to a remote detector housing where the photons are converted into an electrical signal by a silicon photovoltaic cell. A signal processor measures and displays on a real-time basis three temperature characteristics of the turbine blades with response better than 10 ms in most cases. Recent developments include smaller electronics, practical sensor heads, and 5000 h fiber optics. Importance of measuring the blade temperature, potential uses of the data, and actual engine tests are described.