N588JR

On June 17, 2002, AT 1615 eastern daylight time, a Rotorway EXEC 162F, helicopter, N588JR, registered to a private owner, operating as a 14 CFR Part 91 positioning flight, rolled over on its left side at a private airport when the pilot attempted to pick the helicopter up to a hover. Visual meteorological conditions prevailed and no flight plan was filed. The helicopter sustained substantial damage. The commercial pilot and pilot rated passenger reported no injuries. The flight was originating from Spencer Airport, Concord, North Carolina, at the time of the accident.

The pilot stated , "after bringing up power and getting light on the skids, I proceeded to lift off. The left skid seem to stick in the ground, and the right skid proceeded to lift. The helicopter started to roll to the left. I lowered the collective and added full right cyclic. The helicopter kept rolling to the left and dynamic roll over occurred. The main rotor blades struck the ground as we rolled over on the left side. The tail boom stayed intact but buckled. The tail rotor also struck the ground."

A review of Advisory Circular 90-87, Helicopter Dynamic Rollover states, "An increasing percentage of helicopter accidents are being attributed to dynamic rollover, a phenomenon that will, without immediate corrective action, result in destruction of the helicopter and possible serious injury...During normal or slope takeoffs and landings with some degree of bank angle or side drift with one skid/wheel on the ground, the bank angle or side drift can place the helicopter in a situation where it is pivoting (rolling) about a skid/wheel which is still in contact with the ground. When this happens, lateral cyclic control response becomes more sluggish and less effective for a free hovering helicopter. Consequently, if a roll rate is permitted to develop, a critical bank angle (the angle between the helicopter and the horizon) may be reached where roll cannot be corrected, even with full lateral cyclic, and the helicopter will roll over onto its side. As the roll rate increase, the angle at which recovery is significantly reduced. The critical rollover angle is further reduced under the following conditions:

a. Right skid down condition;

b .Crosswinds;

c. Lateral center of gravity offset;

d. Main rotor thrust almost equal to helicopter weight;

and

e. Left yaw inputs."

During a telephone interview with the pilot, he was asked if he experienced any mechanical problems with the helicopter before it rolled over; he responded no.