That's an oversimplification of the issue. First off, you're replacing $40./hr pilots with $72./hr pilots in the right seat, so the savings you're realizing are offset to that degree, plus there are bidding/training issues other than just returning guys to the line later. What about displacement bids? Some pilots may choose to switch airplanes if they are going back to the right seat. Others may take the opportunity to get a 737 type. You also have to figure that many of the dsiplaced FO's would not come back, meaning their traning costs would have to be converted to newhire training costs . . . which would pretty much decimiate any short-term savings.
There is an equation there that would include the number of positions reduced, offset by the increased hourly costs of having senior guys flying as FO's, and associated training costs.
Anyone have a formula to determine savings gained from furlough