Strong fluctuations (SF) of energetic electrons within the local loss cone (LC) from high resolution data on Active, a low altitude, high inclination satellite, are reviewed. The pitch angle diffusion rate of electrons at L > 4 is rapidly changing by one order up to the isotropic pitch angle distribution, corresponding to strong diffusion. The duration of the spikes to nearly strong diffusion limit is increasing with latitude. The statistical study shows the maximum occurrence of fluctuations within LC is in the noon sector and at latitudes 65-70°. Strong geomagnetic activity increases the probability of SF occurrence. One of the possible mechanisms consistent with the observations is the nonlinear precipitation oscillator (Davidson 1986; Davidson and Chiu, 1991). © 1997 COSPAR. Published by Elsevier Science Ltd.203499503Davidson, G.T., Pitch angle diffusion in Morningside Aurorae 1. The role of the loss cone in the formation of impulsive bursts of precipitation (1986) J. Geophys. Res., 91, p. 4413Davidson, G.T., Pitch-angle diffusion and the origin of temporal and spatial structures in Morningside Aurorae (1990) Space Sci. Rev., 53, p. 45Davidson, G.T., Chiu, Y.T., An unusual nonlinear system in the magnetosphere: A possible driver for auroral pulsations (1991) J. Geophys. Res., 96, p. 19353Imhof, W.L., Characteristics of short-duration electron precipitation bursts and their relationship with VLF wave activity (1989) J. Geophys. Res., 94, p. 10079Imhof, W.L., Relativistic electron microbursts (1992) J. Geophys. Res., 97, p. 13829Imhof, W.L., Relativistic electron flux comparison at low and high altitudes with fast time resolution and broad spatial coverage (1994) J. Geophys. Res., 99 (9), p. 17241Kudela, K., Inner zone electron peaks observed by the active satellite (1992) J. Gephys. Res., 97, p. 8681Rycroft, R.J., Interactions between whistler-mode waves and energetic electrons in the coupled system formed by the magnetosphere, ionosphere and atmosphere (1991) J. Atmos. Terr. Physics, 53, p. 849Sandahl, I., (1984) Pitch Angle Scattering and Particle Precipitation in a Pulsating Aurora - An Experimental Study, , Rep. 185, Kiruna SRI, SwedenTrakhtengerts, V.Yu., Mechanism of formation of pulsating auroras (1992) Proceedings of the ICS-1 Conference on Subbstorms, pp. 463-468. , Kiruna, Sweden, ESA SP-335Vampola, A.L., Gorney, D.J., Electron energy deposition in the middle atmosphere (1983) J. Geophys. Res., 88, p. 6267Vampola, A.L., (1994) RADMODLS, Ver. 4.20, , August