On 18 April 1979 a New York Airways' Sikorsky S-61L lost a 35-inch section of one of the five tail rotor blades in flight.
This occurred just after takeoff from Newark Airport (KEWR) in New Jersey, U.S. The crew immediately recognized the problem and initiated an emergency landing back on the airport. The chose to *not* autorotate, as they still had control of the aircraft.
Forty-three seconds after the blade failed the entire tail rotor gearbox departed the aircraft. They were at approximately 150 feet and 60 knots. At that point the aircraft became uncontrollable. It hit the ground in a steep nose-down attitude, yawing to the right. The non-flying pilot was able to get the engines shut down and the battery off prior to impact. There was no fire. Of the 13 people on board, 10 survived.
The NTSB concluded that when the tail rotor/gearbox departed, the center of gravity shifted to 2"
forward of the forward limit.
Whatever the cause turns out to be, if the tail rotor of the AW-139 came off in flight, the crew really did a marvelous job dealing with an emergency which really is a pilot's worst nightmare.
Here's the link to the NTSB report on the New York Airways accident:
http://libraryonline.erau.edu/online...s/AAR79-14.pdf