The Finnish air force has released images showing the effects of volcanic dust ingestion from inside the engines of a Boeing F-18 Hornet fighter, while it prepares to make inspections on several additional aircraft.

Five of the air force’s Hornets were involved in a training exercise on the morning of 15 April, just hours before the imposition of airspace restrictions due to the ash cloud spreading from a major volcanic eruption in Iceland.

One aircraft’s engines have been inspected so far using a boroscope, with melted ash clearly visible on its inside surface. The air force decided to release the images to show the potentially damaging effects of current flight activities, says chief information officer Joni Malkamäki.

 F-18 engine dust 1 - Finnish air force

F-18 engine dust 2 - Finnish air force

Both images © Finnish air force

“The images show that short-term flying can cause substantial damage to an aircraft engine,” the air force says. Continued operation could lead to overheating and potentially pose a threat to the aircraft and its pilot, it adds.

Checks will soon be made on the other four aircraft involved, and some engines will be removed to help Finnish company Patria – which provides in-service support for the nation’s F-18 fleet – to assess the extent of any damage caused. Its fleet comprises 55 single-seat F-18Cs and seven two-seat trainers, with each powered by two General Electric F404-402 engines.

Finland halted air force training flights yesterday, but the air force will continue to perform operational sorties as required, such as air policing missions and national security tasks.

One of its BAE Systems Hawk jet trainers also flew from Kauhava air base twice yesterday carrying an air sampling pod which collected dust from the atmosphere at various altitudes.

 Hawk sampler - Finnish air force
© Finnish air force

The air force is sharing the gathered information with the Finnish civil aviation authorities, and says it will stage more such flights as requested.

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