Allen Pearson was the Director of the National Severe Storms Forecast Center from 1965-79 and began to collaborate with Dr. Fujita on tornado physical characteristics soon after the 1970 Lubbock Tornado. They bounced ideas off each other and the Fujita scale(F-scale) and later the FPP scale was the result. Pearson had devised the computerized encoding of the tornado base, which included the F-P-P estimates. Wikipedia
The definitive Wikipedia entry for Allen Pearson. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Allen_Pearson
T he Fujita Scale (also known as the Fujita-Pearson Scale) may not be a perfect system for linking damage to wind speed, but it had distinct advantages over what had gone on before its inception. www.tornadoproject.com/fscale/fscale.htm