Would like to direct everyone’s attention to page twelve of the report.
In separate paragraphs, (specifically para #3 and para #5), it appears that CAB can’t decide which primary aileron cable separated. Keep going to page thirteen, where the report writer is convinced there are two pairs of aileron cables, not one, and that both pilots’ cables separated in flight.
The description I favor (pilot’s cable failure) would seem to suggest that their situation was dire, but that left wing down was available, in both manual and boosted modes.
The “alternate conclusion by CAB” (failure of co-pilot’s cable) suggests nothing could have saved them. Key words: “in tension”.
From the schematic legend:
The cables to the empennage run in pairs - two sets for the elevators, two sets for the rudder, both designated ‘primary’ in the above image. If either set of cables breaks, the other set would be unaffected. There is also one pair each for the empennage trim tabs. There is only one primary cable pair running to the wing root for the ailerons. An unscrewed turnbuckle on a cable running from the flight deck to the aileron boost pack- age was the cause of the crash. If there had been two sets of cables to the wing, there would have been no crash.
My assumption of the schematic is that any remaining cable remains in tension with the boost quadrant. Something has to retain the cable to each yoke, or there would be insufficient friction (traction) for either yoke to move the cable.
Such a design would allow for deflection of an aileron dependent on the yoke with the remaining tension.
Aileron return to neutral? Blowdown. (Release pressure).
In the case of 706, the co-pilot cable would articulate left aileron up, right aileron down, since the ailerons are directly connected to each other. Co pilot yoke has authority to roll left, but a following Roll right is unavailable, pilot yoke disconnect prevents “pull” on the quadrant.
I can’t believe this was not part of the Lockheed design. I believe it is. The clue? There are two tensioning stations....and a connector rod between yokes.
BTW. My schematic shows the yokes rigged in tandem, with pilots yoke at the end of the cable loop.
Last edited by Concours77; 4th Jan 2018 at 19:58.