[giarc]

I suspect this would be much, much quieter than a regular gasoline engine correct? These smaller planes are loud.

[bittercynic]

Much of the noise from small planes is from the propeller(s), so it might not help much.

[darksaints]

For retrofits like this, the noise will go down a bit because the engines are inside the fuselage.

[nordsieck]

I believe the real benefit of electric planes is the maintenance cost. Most small planes require that the engine be torn down and inspected / parts replaced on a regular (per flight hour) basis.

An electric motor may have a longer service life than an engine, and is almost certainly much less expensive to service.

[throwawaysea]

Not necessarily - a gas engine operates at a different RPM and has a gearbox to the prop while these are direct drive.