Will taxiing help engine in airplane sitting idle

[PeterNSteinmetz]

So I have always heard that is not good to let a light aircraft sit idle for over a month. Mostly because water vapor in the cylinders can cause corrosion and also because various fittings dry out.

Question is - will taxing the aircraft if it can‘t be flown for about 30 minutes help this? That seems like it should definitely warm up the engine and the oil.

 

[Jim Logajan]

So I have always heard that is not good to let a light aircraft sit idle for over a month. Mostly because water vapor in the cylinders can cause corrosion and also because various fittings dry out.

Question is - will taxing the aircraft if it can‘t be flown for about 30 minutes help this? That seems like it should definitely warm up the engine and the oil.

Lycoming has a service letter on that subject:
https://www.lycoming.com/sites/defa...%20for%20Active%20and%20Stored%20Aircraft.pdf

They say:
"Engine temperature and length of operating time are very important in controlling rust and corrosion. The desired flight time for air cooled engines is at least one continuous hour at oil temperatures of 165°F to 200°F at intervals not to exceed 30 days, depending on location and storage conditions. This one hour does not include taxi, take-off and landing time."

 

[rotorwrench]

Question is - will taxing the aircraft if it can‘t be flown for about 30 minutes help this? That seems like it should definitely warm up the engine and the oil.

Not at all and may even make things worse. Its more than just "warming up" the oil. As mentioned above it requires a sustained effort that can only be reached in flight. In general, the main issue is that the engine combustion process results in about 70% CO2 and 30% water vapor, with some trace elements. So by only taxing or ground running the engine you can actually induce more water vapor into the engine then you are removing. If unable to meet the recommended minimums of one hour flight time per 30 days, then you become money ahead to follow the OEM preservation guidelines. Regardless, location can have an impact on these recommendations but common sense usually prevails on when and how to minimize internal engine corrosion. In other words, fly the plane.