Originally Posted by
pattern_is_full
Some airlines actually eventually had plates bolted across the flap-handle quadrant to prevent selecting flaps 40.
.
It was part of the Stage 3 noise compliance. The noise certification is an average of a takeoff and landing. The normal engined 727s exceeded the standards for takeoff but by reducing the amount of sheet metal in the breeze they would come in below the limit for landing and by enough margin to balance out the TO noise.