Recently it has been reported that autoxidation of a Jet-A fuel which occurs during passage through heated stainless-steel tubing is accelerated by the tubing walls and that this effect is mitigated as the surface becomes fouled. To investigate the generality of this finding, we have studied the depletion of dissolved oxygen in 16 aviation fuels in a single-pass tubular heat exchanger. Experimental conditions of temperature and tube dimension were held constant, but the chemical composition of the inner wall surfaces was varied. Reaction was compared in commercial stainless-steel (304) tubes and in passivated or surface-treated (Silcosteel) tubes which are noted for their inert inner walls. The aviation fuels selected for study ranged from the highly thermally stable JPTS to an unstable Cu-doped Jet-A. The fuels contained a fixed amount of oxygen (air-saturated at room temperature) and were stressed under identical conditions at 185 degrees C during passage through 0.216-cm-i.d. tubing. Results reported herein show that autoxidation occurring as fuel flows through stainless-steel tubes is accelerated as compared to that occurring in treated tubes. The magnitude of this effect is fuel dependent, ranging from a low of 10-20% (barely detectable) to similar to 75%. The role of surfaces in catalyzing aviation-fuel autoxidation in narrow-bore tubing and possible ramifications with regard to surface fouling in aircraft fuel lines are discussed.