DIY Not Welcome In Aviation

The great Kiwi number 8 wire, ‘can-do’, DIY mentality is good for house renovations, broken lawnmowers, and high performance go-karts – just leave it out of the aircraft maintenance.




Recently, a light aircraft owner decided to save a bit on maintenance by removing a vacuum pump after it failed in flight, causing the Artificial Horizon (AH) to wander. The owner booked the aircraft in for maintenance, confident that he could legally fly it to the maintenance base without an AH on a private VFR flight.


To save himself some labour costs, he removed the dry vacuum pump himself before departing. He took off, raised the flaps and then adjusted the power setting. Immediately he noted the prop rpm response was not normal and the engine sounded noisy. He decided to carry out an emergency landing onto a nearby airfield. It was a wise choice.

The owner’s DIY efforts had left the aircraft bleeding oil, and the engine had been moments away from seizing completely.

The dry vacuum pump effectively blanks an oil pressure port that provides lubrication to an oil-lubricated vacuum pump, on certain aircraft. These are known as ‘wet’ pumps. The differences would be obvious to any appropriately rated Licensed Aircraft Maintenance Engineer (LAME). By removing the ‘dry’ pump, the owner had left the oil free to exit the engine at speed. Had a LAME removed the pump, they would have immediately installed a blank to the ‘wet’ pump port to keep the oil where it needed to be.

Fortunately, the owner was able to land safely, without injuring himself or further damaging the aircraft.

His maintenance bill though, had just gone through the roof. Aircraft maintenance is a skill that takes years to hone. Non-LAMEs who wish to carry out maintenance must be under the direct physical supervision of an appropriately qualified person. This event serves to illustrate why.

This story show the importance of aeronautical engineers to the aviation industry. Learn more about the aeronautical engineering career pathways by clicking HERE, or read about Chris Dunand and Jenn Harmon who are both training to be engineers.


This story has been reproduced from CAA's Vector Magazine.
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