During engine R&R or during a 120/240-month inspections, West Star Aviation has been discovering chafing of the fixed cowl on Global aircraft from a bleed air clamp.  This chafing has been observed roughly 15 to 18 times over the past two years.

The issue requires a Technical Variance, in which Rolls-Royce will either call out a repeat inspection of the area.  Technical Variance normally requires a reoccurring inspection of the chaffed area every 50 Flight hours up to 200 flight hours.   At 200 flight hours a blend or weld repair will be required. If weld repair is required, the engine and fixed cowl must be removed in order to complete the weld.

In some instances, Rolls-Royce may require an immediate repair if the chafe is too deep.  The repair for this issue is a titanium weld repair, with the process taking about 7 to 9 working days.