Interesting and thank you. I know nothing of the retractable 'skid plate' mechanics, but if it helped to prevent major damage on TO or landing, heck yes. Retractable with the LG is also new, but why the heck not; good engineering. What I do not quote get is why this protective device did not also include some kind of 2" - 3" 'feeler,' before the protective unit contacted the ground. My only guess is that when at V2 and attempting to rotate/lift off, the time is too short to make a substantial correction in AOA - or, none of the three-person crew needs any additional distractions at that instant. Perhaps the same thing. In other words, if the butt end is withing 3" of a strike, it is too late for any correction, they are going flying - no matter what surface may contact the ground; there is no time for AOA correction.
Of course, the next question has to be, in a 'normal' take off, how much butt end clearance is expected with the 727-200? I've seen hundreds, but only a few obvious strikes. Many looked close, but... Does anyone know what the performance engineers considered as 'normal?' Thanks. (no funny face here!)
As as as aside, I'll also note that my own observations of early jets, 727-100 and -200 especially were the first realization that 'jets,' generally took off with a *much* higher AOA than did the old props. To a young teen in the early 60s, the straight-wing props sort of begged to fly, while the jets could not get off the ground soon enough. To my then uninformed eye, the differences in raw power, initial AOA and initial climb were shocking; not only could the jet lift off early, it could maintain that high angle, but also accelerate. My guess is that more than a few pilots also had some difficulty understanding that new level of 'thrust. Ideas?