I'm as curious as Swedish Steve on why that configuration was chosen. There has to be a good reason --- I suppose.
I'm also curious as to the history of Take-Off Configuration Warnings. The first one I saw was on a Gulfstream II, built around 1970? Yet Boeing claim a US Patent on the bones of any system, in 1978. I know something of Patents and the GII system predates the Boeing claims - no doubt. More to the point, if the Boeing Patent
was valid, the GII being much simpler, it says there was no Take-Off Configuration Warning (as we now understand it) prior to 1978.
United States Patent 4,121,194
Downey , et al. October 17, 1978
Assignee: The Boeing Company (Seattle, WA)
Take-off warning system for aircraft.
Abstract. A logic controlled take-off warning system having a circuit for enabling the logic controlled take-off warning system at engine thrust levels exceeding a predetermined value which is less than minimum take-off thrust of the aircraft and greater than thrust required for normal ground operations, provided also that the aircraft is on the ground. When the logic controlled take-off warning system is enabled, a take-off warning horn is subsequently energized when any one of a plurality of undesired take-off configurations exists.