In the last few years, Bell Helicopter has received reports of main transmission generating metal particles. Subsequent transmission teardown revealed significant mechanical damage to the sungear and planetary pinion gears.
Several parts were received at Bell for evaluation but none of these parts revealed physical or material inconsistencies.
Further investigation revealed that although the aircraft may be operating within the limits listed in the current flight manual, damage to the transmission planetary pinion gears and mating gears may occur due to excessive mast bending which causes planetary system misalignment.
This bulletin introduces a revision to the Flight Manual which includes a revised VNE airspeed limits decal. In addition, the manual also includes a revised restricted center of gravity envelope along with a secondary VNE airspeed limits decal. Airspeed limits listed on the secondary decal will apply for the duration of a flight whenever the aircraft is loaded with a C of G within the crosshatched area of the new restricted center of
gravity envelope.
Above taken from the ASB issued okt 30 2009.
Well this mean VNE down to 120kts in most cases right, which is a major input in operating theses helicopters and limiting factor
Would like to hear your thoughts about this, and from those who are operating 430.
Is this mast bending due to major error in the original design of this helicopter?
Has anyone here had this main-gearbox problem ?