Media Blasting of Paint on Sikorsky Rotor Blades
In recent years media blasting of aircraft parts to remove old paint has become an ever-increasing method as a substitute for chemical paint stripping.
An operator should be aware of the potential consequences if he wishes to utilize this method of paint removal.
First, the OEM’s specs and procedures should be reviewed to determine the process and which parts are approved for media blast paint removal. At this time Sikorsky does not approve of any media blast system for use on its metal rotor blades.
Second, if regardless of OEM specs an operator is determined to use a media blast system, caution should be taken. The use of media equipment in inexperienced hands can have serious and costly consequences. The below picture illustrates what may happen.
The two S-61 blades shown below were media blasted by an inexperienced individual who cost his owner in excess of US$22,000.00 for pocket replacement repairs. The pocket skin on both the main rotor and tail rotor blade is made from .012” aluminum material. By aggressively blasting in a single area too long the material will stretch between the ribs rendering this undesirable look and an unserviceable rotor blade.
Third, the owner/operator also needs to review whether or not its repair station authorization extends to cover rotor blade type of repairs. Rotor blades are not lumped in with blanket component type authorities. The operator or his employees could in fact be opening the company up to an unanticipated liability.
The reason Sikorsky does not allow entire rotor blade paint stripping and repainting in either the Maintenance Manual or the Structural Repair Manual is because the owner/operator does not have the proper authorizations, balance equipment, procedures, tooling and personnel to completely strip, repair, refinish and rebalance the blade back to a known master. The balancing of the blade is as critical to a rotor blade as the gear setting is to a gearbox. Sikorsky only allows touch up type of repairs to the painted surface.
For more information contact Paul Bolton at (407) 846-6780.
This notice is for information purposes only and does not condemn any blade without a more detailed inspection of the blades.