Power and helicity density spectra of the interplanetary magnetic field (IMF) are determined from data measured on board Helios spacecraft at times of three solar proton events (SPE) when they were at heliocentric distances ranging from 0.3 to 0.5 AU. The events were selected to represent different levels of perturbation in the IMF. The obtained spectra are also different in the three cases. These are used to calculate pitch angle scattering coefficients according to the classical quasi-linear theory (QLT) treatment of particle propagation in fluctuating fields. Results reflect that in the three cases helicity effects are negligible and the energetic particle mean free paths deduced from the pitch angle diffusion coefficients are the same regardless of whether helicity effects are or are not included in the calculation. Note, however, that the mean free paths calculated here are markedly different in each case, and all of them are larger than those deduced by Jokipii and Coleman [1968>, commonly referenced as the QLT result. ¿ American Geophysical Union 1993