Off Topic Airplane Talk

[4est]

13 hours ago, mansr said:

Manufacturing and keeping inventory of all engine parts in left and right versions would certainly add cost. I suppose the benefit depends on the size of the plane. Also bear in mind that the plane must be able to fly on one engine, so the trim surfaces to balance the forces are always needed. What's an example of a plane with counter-rotating props?

It doesn't take much to make an engine run backwards even if there wasn't a gear box.