Honeywell’s engine division scored a unique opportunity last month when two TPE331-5 engines arrived at the company’s Phoenix headquarters. The two engines were removed from a Dornier Do-228 operated by the UK’s National Environment Research Council on flights into volcanic ash clouds resulting from the eruption of Iceland’s Eyjafjallajökull volcano. The Dornier flew 10 hours in the heart of the ash cloud and 22 hours in the outer zone.

Honeywell technicians and engineers planned first to run the engines in a test cell to evaluate their performance and do a borescope inspection to see what the internal parts look like. Then the engines will be disassembled. “We’ll look at the compressor all the way through the turbines and get a better understanding of what this type of material does to a gas turbine engine operating in this type of environment,” said Ron Rich, Honeywell vice president of propulsion systems. “We’re going to try to understand what [flying in volcanic ash] means operationally. We want to help operators understand the effects of flying in this environment and give guidance on what the operational rules ought to be.”

Two other Honeywell-powered aircraft have flown through ash clouds, a TFE731-5BR-powered Falcon 20 flying out of Germany and a UK-based BAe 146 powered by Honeywell ALF502 engines. “We’re not sure whether we’ll gain access to those,” Rich said. But the knowledge gained from examining the TPE331s, he added, “will have applicability to other Honeywell turbine engines.”

The examination and teardown of the TPE331 should take about a month. “We look forward to what we’re going to discover,” Rich said.