- ACCIDENT DETAILS
Date: October 21, 1977
Time: 10:30
Location: Mindoro, Philippines
Operator: Military - U.S. Marine Corps
Flight #: ?
Route: ?
AC Type: Sikorksky CH-53 (helicopter)
Registration: 157139
cn / ln: ?
Aboard: 37   (passengers:33  crew:4)
Fatalities: 24   (passengers:?  crew:?)
Ground: 0
Summary: After lifting a water container the aircraft began rotating until control was lost and contact was made with the ground, shearing off the tail rotor and a large portion of the tail assembly. New engines were installed in the CH-53s to increase the power of the main rotor and on a whole to make the helicopter more powerful. However, it was soon evident that the tail rotor could not balance the increased power created by the main rotor. Under certain conditions the aircraft would become unstable and lose directional heading. Sikorsky warns of these conditions. To compensate for the mistake that had been made, Sikorsky designed and tested a bell crank system to stabilize the rear rotor. After seven years, this helicopter was still not retrofitted with the bell crank system. Gross weight of the container exceeded the lifting capacity of the helicopter. No restrains used by the passengers.
Sources

Return to Home Page

Copyright Richard Kebabjian / www.planecrashinfo.com