NTSB Aircraft Accident Report, United Airlines Flight 389 Attachment 2
National Transportation Safety Board (NTSB)
<a class="external free" href="https://en.wikisource.org/wiki/Page:NTSB_Aircraft_Accident_Report,_United_Airlines_Flight_389.pdf/44">https://en.wikisource.org/wiki/Page:NTSB_Aircraft_Accident_Report,_United_Airlines_Flight_389.pdf/44</a>