Ceramic materials a r e a promising candidate for 1400high-temperature structural applications because of their high melting point, high-temperature strength, stiffness, oxidation resistance, and low density. o However, their intrinsic brittleness limits their widespread applications. The incorporation of strong and stiff fibres into a ceramic matrix imparts damage & tolerance capability to the material. The application of continuous fibre ceramic composites (CFCCs) in critical components, such as jet-engine turbine blades and tubular products for heat exchangers, involves thermal or thermomechanical cycling. However, thermal or thermomechanical fatigue studies, especially those simulating the £omponent's cyclic service environment, are scarce. The thermal and thermomechanical fatigue research of CFCCs has been limited to glass-based composites subjected to the photon or induction hcating and thermal cycling (500-1100°C) [1-3]. The cycling lacks the rapid heating and corrosion effects of jet-fuel flame impingement. It is thus inadequate to simulate the complex interaction of the thermomechanical loading, erosive and corrosive environment of a gas turbine engine. To our knowledge, the present study is the first report of burner-rig thermal fatigue behaviour of CFCCs under impinged jet-fuel flame. The [(0/90)5/O]s SCS-9 TM SiC fibre (30 vol%)/ Si3N4 cross-ply laminated composite was fabricated using hot-pressing at 1650 °C and 17.2 MPa for 1 h by Textron Specialty Materials, Lowell, MA, USA. The matrix composition was 92.5wt% Si3N4, 5.0 wt% Y203, 1.5 wt% MgO, and 1.0 wt% A1203. The composite was machined to 12.7 mm x 3.175 mm x 152.4 mm rectangular bars. The burner-rig thermal fatigue tests under constant applied stress were conducted using the Mach 0.3 atmospheric pressure durability test station at NASA 2oo Lewis Research Center, Cleveland, OH, USA. The ~" flame was produced using a "can-type" combustion ~150 chamber. The time to runout was arbitrarily selected 100. as 1000 cycles due to the operating cost of the test facility. The constant tensile stresses of 16.8, 84.0, -~ o B 50 110.0, 125.0, 140.0, and 168.0 MPa were applied to ~. the specimens during thermal cycling. The cyclic 0 temperature profile of 60 s 1350 °C ftame impingement, followed by a 60 s passive, ambient temperature cooling, is shown in Fig. 1. In order to determine the failure mechanism of the