Was so critical on the 727, that the VHF antenna (a "blade antenna") mounted on top of the fuselage was anti iced, in fear of ice ingestion into nš 2 engine.
Wasn't this also true of the DC-10?
And bad stall characteristics of T-tail airplanes required "stick pushers" for certification.
The 727 - and most other T-tails - did not require stickpushers originally per the FAA. It was when the CAA was accepting the type that the pusher was added. But that was after a couple high-sink-rate 727 accidents elsewhere.