ALPA report on the crashPDF (2.70 MB), p. 2 (PDF page 6 of 97). "The study group notes with approval that the official report of the spanish government has, itself, included a section on human factors involved in this accident. We feel that this is an excellent beginning toward a better understanding of the causal factors of aviation accidents, an idea whose time has finally come."
Official reportPDF (5.98 MB), section 5.2, p. 38 (PDF page 41 of 63): "...these circumstances could have induced the co-pilot not to ask any questions, assuming that his captain was always right"
ALPA report on the crashPDF (2.70 MB), p. 22 (PDF page 26 of 97). "Both pilots were contending with heavy demands on their attention as the visibility rapidly worsened. The flight engineer, to the contrary, had completed the heaviest part of his workload and was now reverting to an instrument monitoring mode."
ALPA report on the crashPDF (2.70 MB), p. 22 (PDF page 26 of 97). "It is our opinion that the flight engineer, like the pilots, did not perceive the message from the controller to the Pan Am asking them to report when runway clear. (Because of the use of the address "Papa Alpha)."