Pratt & Whitney Canada, manufacturer of the PW610F engine that powers the Eclipse 500 very light jet, and Eclipse Aviation are jointly investigating the cause of a carbon buildup that resulted in an in-flight engine shutdown earlier this month. Although details of the problem are unavailable since no report has yet been issued by the FAA or the NTSB, P&WC was “made aware of this,” a P&WC spokesman said, “and we are currently collaborating with Eclipse to investigate the issue. Initial findings indicate that carbon appears to form in the combustor during high-altitude operation with full cabin bleed selected. Both teams are pursuing the investigation at this time. However, it is important to note that there are no recommended changes to maintenance or operational procedures associated with the PW610F engine.” The PW600-series engine powers the Eclipse 500, Cessna Citation Mustang and under-development Embraer Phenom 100. To date, the Eclipse fleet has accumulated more than 50,000 operating hours since late 2006, according to the P&WC spokesman.