November 16, 1982. That was the day Boeing nearly lost a 757 during the flight test program. It was during a flight into known icing conditions to test the 757’s deicing systems. Two inches of ice built up on the wings. At the time, Rolls Royce thought a flexible spinner hub on the fan would prevent ice formation instead of a traditional heated fan spinner which would be heavier. It didn’t work. Large chunks of ice from the spinners were ingested by the engines, damaging the fan blades to the point that the flight crew had to throttle to idle and coast back to Boeing Field- to descend into terrain around Seattle with insufficient engine power to go around left many shaken, from the flight crew, test engineers, and FAA reps onboard.
Rolls had to hurriedly design a traditionally heated spinner hub for the RB211 engines which met the icing criteria and testing. You can read a little bit more about this incident in a Seattle Times article about the 757 here: http://seattletimes.com/news/business/757/part05/