C-141 Inflight Open Thrust Reverse
October 1973, during the Yom Kippur Airlift
I was in the jump seat when we were taking off from CHS going to Savannah on a mission to pick up a replacement air defense radar for the Israelis. We were empty with a min fuel load, or I wouldn't be writing this.
We broke ground, and immediately we had a problem. Violent doesn't even begin to deserve the response of the aircraft. We went into a radical yaw, and roll left less than 100 feet above the ground. The AC at the controls was a FEAC, and a good pilot, and he did what he was supposed to do--keep it under control. When he got it out of the dive, all I can say was I had never seen so much of the ground in an aircraft windshield. What was doubly bad, was the fact that there were no warning light indications at all (explain why in a minute).
I thought initially that the left flap had departed. The scanner ran back to look and told the AC that # 1 was in reverse. The engineer at the panel checked the circuit breakers and saw one popped and pushed it in, and the engine came out of reverse. So what caused the problem?
Prior to the flight, MX was working on that reverser. They manually cranked it open for the work. When they work on a reverser, they also pull the reverser power CB for safety reasons. So they finished the work and cranked the reverser back closed. Here's what apparently happened. When they cranked it in, they didn't crank far enough to engage the over-center locks that normally keep the reverser positively locked in place. When the MX man went in to engage the CB, he didn't push it all the way in. When the FE checked the panel, the CB looked engaged but wasn't. So the reverser was unpowered and not locked when we took off. A soon as there was enough slipstream, it just flopped open the unpowered reverser.
What contributed/caused the problem was this, and IMO it was a design flaw in the C-141. The "not locked" and "extended" warning lights are powered through the same CB that provides the reverser power. So when the MX guy pushed in the CB, he did so not quite enough. There was no "not locked" light on the TR panel because it was unpowered. When the FE did his checks--ditto, when it extended on takeoff, there was still no warning. The CB had to have popped out all the way sometime after the FE checked the CBs, and it was not noticed.
There was an "adding insult to injury" facet of this incident. We pulled up downwind for an emergency return and called the problem into ACP. About 30 seconds later, ACP made this call. "By direct ordering of the President of the United States, you will continue to Savannah". The Israeli's only air defense radar in the Sinai had been knocked out by an Egyptian missile, and they were blind and in a real pickle. This mobile GCI radar we were getting in Savannah was state-of-the-art and was the only one we had. I guess it came from the Army. We weren't really happy about having to continue the mission after nearly dying, but that's life in military aviation, and you do what you have to do.