This investigation was opened based upon allegations made by the New York City Transit Authority (NYCTA) regarding the operation of a subject lift installed on one of itsMCI motorcoaches.On March 6, 2012, an occupied powered wheelchair rolled off an elevated subject lift, injuring the occupant.While looking into this incident, ODI found that NYCTA personnel had failed to utilize the original equipment wheel chair restraint (an interlocked safety belt in this case).Normally, failing to use the belt would mean the lift could not be raised.This is because, to comply with FMVSS 403, S6.4.7.1 and S7.7.2.2, the lift manufacturer's (Ricon) wheel chair retention device incorporates an interlocked belt.With the required interlock, if the belt is not latched, the lift will not operate.However, NYCT failed to use the belt and intentionally disabled the interlock.ODI is unaware of any other incidents of wheelchair roll-away involving the subject lifts. Given these facts, a defect trend related to the subject lifts wheel chair retention system has not been identified and this PE is closed.