DC8-63's used to reverse the inboards on descent for added drag as the speedbrakes were kinda puny. Had a wonderfull system called "bucket dump" which would ensure that the ****** would un-reverse when you wanted it. In the early days of the 747 as the sun rose over the cold dark Atlantic, a P&W rep asked one of the drivers when they had shutdown Nr 4 engine. He said they hadn't, and the P&W guy pointed out that the NR 4 aft sleeve was in reverse. The driver scarpered back to the cockpit as this was news to them, they hadn't felt a thing. I think that this incident and that stupid push-pull cable system prompted Mr Boeing to take the aft reversers off the Queen of The Skies.