Yeah, I figure out that would be the only logical reason to make the recommandation for those aircrafts, however, as far as I know, it is not true. Most of big jets use single jackscrew design to actuate the horizontal stabilizer, so it's not the case. In fact the only one that I know they use different systems are DC-10,MD-11 (I hope my memory is not at fault) which use double jackscrew and L-1011 which has hyd actuated. The others, including Airbus, I know they have just a single jackscrew.
Maybe there are particular design features which make it different even being just one jackscrew. That's why I'm asking, I hope someone here has some detailed knowledge on these designs to clarify.
Last edited by David36; 14th Jan 2013 at 09:01.