In helicopters, the most critical component is the Main Gearbox (MGB). The MGB usually has its own lubrication system that includes chip detectors. Their function is detection and early warning of the wear and tear of internal components. However, they collect any magnetic debris, also oil can cast-off material.
Chips detectors are electrically connected to cockpit warning lights and may have a burn-off capability. Pilots will be able to zap and clear the warning during flight.
Oil filling is done directly into the MGB. Some oil filler necks might have a coarse filter, but nothing that prevents small FOD contamination. The oil introduced to the MGB is out of the can and perceived to be clean.
However, engineers and mechanics often uses various improper tools like screwdrivers and pliers to open turbine oil cans. Tools that will create metal debris cast-off from the can material and tools. The debris will unnoticed fall off inside the oil can and mix with the oil.
Watch this video to see how much metal is introduced to the inside of a turbine oil can, when opened with a screwdriver. Read about “The shocking inside of a turbine oil can opening”.
Photos: Screwdriver opening / Magnetic oil can material cast-off
Pouring the oil into the MGB, you unknowingly contaminate the MGB and lubrication system.
The solid particles presence in oil reduces its lubricating properties and leads to wear. Contamination by particles even as small as 5 µm affects the reliability and safety of the lubrication system. Particles bigger than that – Even worse.
Bearing and gear failure often starts with the roll-over of a solid metal particle. Eventually leading to gearbox failure if undetected or ignored. Read more about particle roll-over
Conclusions from NTSB reports: MGB failure due to wear debris ignored. MGB failure due to chip detector indications ignored.
Did these accidents happen because you get used to having chip warnings. You get lulled to sleep by “non-wear” chip warnings created by oil can material cast-off, because of using improper tools and technique. When a “real wear” chip light warning comes on, it is ignored or zapped – it anyway “Always happens after they top up the oil.”
Photo: Clear particle roll-over dents with raised edges on Airbus H120 planet gear. Only few of many shown.
Read more about “Prevention is the best way to avoid FOD in turbine engine oil systems”
TheCanKey is the only FOD free oil can opener on the marked. It is tested and certified by Saybolt Laboratories not to leave any debris whatsoever in the oil can during the opening process.
Use TheCanKey turbine oil can opener to ensure not to introduce FOD to your oil system when servicing or filling oil. It is an easy, proper and effective way to prevent FOD. Using TheCanKey FOD free oil servicing tools will ultimately save costs and improve overall safety and performance of the gear box.
Read more about TheCanKey FOD free oil service tools here: www.TheCanKey.com
