link for Tom https://www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwiPo4SgjsHLAhUqS5oKHVUIALoQFggdMAA&url=http%3A%2F%2Frgl.faa.gov%2FRegulatory_and_Guidance_Library%2FrgMakeModel.nsf%2F0%2F77a105d3d5ce2acb862574250061f9cb%2F%24FILE%2FE00078NE.pdf&usg=AFQjCNFRleevayQsn_I_3lObRdkdg09nTw&sig2=N0K_8pfbKhoD8a67IQTOsQ&cad=rja