A simple planetary train with 18 teeth in the sun and 114 teeth in the ring is used in an aircraft gearbox. The teeth have a 3-mm module in the normal plane, and the helix angle is 0.40 rad. The manufacturer wishes to replace the original gearing with a 24-tooth sun and a 108-tooth ring using the same arm. What is the helix angle for the replacement gears if teeth of the same module are used?