That old 737 pilot manual lays out a scenario where a much more elaborate pilot response is required than the one Boeing outlined in November and has reiterated ever since. "They couldn't turn the manual trim wheel." This heavy force would resist the pilot's manual effort to swivel the stabiliser back down. This analysis suggests the stabiliser trim wheel at the Ethiopian captain's right hand could have been difficult to budge. More detailed instructions that conceivably could have saved the plane in this situation are provided in the 1982 pilot manual for the old 737.

Source: Stuff April 03, 2019 15:22 UTC