What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(.19) On February 1, 1999, at 1010 hours mountain standard time, an aerospatiale AS350B, N32GA, operated by silverado helicopters, inc., d.b.a. heli usa, experienced the sudden loss of the entire left side passenger window during descent over the Grand Canyon National Park, Arizona. The window impacted and substantially damaged a tail rotor blade (paddle). Visual meteorological conditions prevailed during the on-demand sightseeing flight that was performed under 14 CFR 135. The commercial pilot landed without further mishap, and neither he nor the six passengers were injured. The aerial tour flight originated from las vegas, Nevada, at 0928. The pilot reported that during his preflight inspection he had looked at the window and it was not damaged. During the flight the passenger seated next to the window was not observed taking pictures or "elbowing" the window. The operator reported that several months prior to the mishap the company had replaced window. The replacement window was not manufactured by aerospatiale. The accident was not reported to the safety board for several days after the helicopter was returned to service and a replacement tail rotor blade installed. The window and its associated retention gasket (seal) remain missing. (-23)accident occurred while aircraft N32GA was descending from an enroute cruise phase to approach onto the ramada heliprt pad within the Grand Canyon. During the descent, the left passenger window departed the aircraft and struck the tail rotor blade. Upon examination of the tail rotor, it was found by aerospatiale factory trained personnel that the tail rotor was unrepairable and a total loss.
As the FAA filed it
(.19) ON FEBRUARY 1, 1999, AT 1010 HOURS MOUNTAIN STANDARD TIME, AN AEROSPATIALE AS350B, N32GA, OPERATED BY SILVERADO HELICOPTERS, INC., D.B.A. HELI USA, EXPERIENCED THE SUDDEN LOSS OF THE ENTIRE LEFT SIDE PASSENGER WINDOW DURING DESCENT OVER THE GRAND CANYON NATIONAL PARK, ARIZONA. THE WINDOW IMPACTED AND SUBSTANTIALLY DAMAGED A TAIL ROTOR BLADE (PADDLE). VISUAL METEOROLOGICAL CONDITIONS PREVAILED DURING THE ON-DEMAND SIGHTSEEING FLIGHT THAT WAS PERFORMED UNDER 14 CFR 135. THE COMMERCIAL PILOT LANDED WITHOUT FURTHER MISHAP, AND NEITHER HE NOR THE SIX PASSENGERS WERE INJURED. THE AERIAL TOUR FLIGHT ORIGINATED FROM LAS VEGAS, NEVADA, AT 0928. THE PILOT REPORTED THAT DURING HIS PREFLIGHT INSPECTION HE HAD LOOKED AT THE WINDOW AND IT WAS NOT DAMAGED. DURING THE FLIGHT THE PASSENGER SEATED NEXT TO THE WINDOW WAS NOT OBSERVED TAKING PICTURES OR "ELBOWING" THE WINDOW. THE OPERATOR REPORTED THAT SEVERAL MONTHS PRIOR TO THE MISHAP THE COMPANY HAD REPLACED WINDOW. THE REPLACEMENT WINDOW WAS NOT MANUFACTURED BY AEROSPATIALE. THE ACCIDENT WAS NOT REPORTED TO THE SAFETY BOARD FOR SEVERAL DAYS AFTER THE HELICOPTER WAS RETURNED TO SERVICE AND A REPLACEMENT TAIL ROTOR BLADE INSTALLED. THE WINDOW AND ITS ASSOCIATED RETENTION GASKET (SEAL) REMAIN MISSING. (-23)ACCIDENT OCCURRED WHILE AIRCRAFT N32GA WAS DESCENDING FROM AN ENROUTE CRUISE PHASE TO APPROACH ONTO THE RAMADA HELIPRT PAD WITHIN THE GRAND CANYON. DURING THE DESCENT, THE LEFT PASSENGER WINDOW DEPARTED THE AIRCRAFT AND STRUCK THE TAIL ROTOR BLADE. UPON EXAMINATION OF THE TAIL ROTOR, IT WAS FOUND BY AEROSPATIALE FACTORY TRAINED PERSONNEL THAT THE TAIL ROTOR WAS UNREPAIRABLE AND A TOTAL LOSS.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.