Runaway Prop

by Capt. Ed Mitchell

On December 20th, 1947, we left Westover, MA with a load of Christmas trees for the U.S. Troops at Keflavik. We proceeded on to Schipol in Amsterdam to pick up a return load. The company told us we could take whatever crew rest we wanted in order to be home for Christmas. Joe Halsmer was the captain, Walter "Jorgy" Jorgensen was the flight mechanic, George Forero was the radio operator and I was the navigator. Those are the names I remember, for we were all involved in the hectic return home. After minimum rest, we loaded the cargo, headed to Shannon for fuel and our "Goodies," and took off across the pond. We were going home for Christmas.

Everything was going fine till we got to 30 west [30 degrees west longitude] and then the 'wheels' came off. Suddenly there was a horrible noise. Unless you have experienced it, there is no more frightening sound than a runaway prop. We had passed mid-point, so it's on to Gander. Jorgy and Joe retarded the throttles so the prop would not come off. This retarded our airspeed to a slow 120 mph. They tried every thing they could to feather the prop, to no avail. I have a wonderful memory of Jorgy, up on the top bunk with his baseball cap down over his eyes trying to come up with a solution to the problem. Every five minutes, he would come up and say "Lets try this" but nothing worked.

In the meantime, I was having my own problems. The drift meter lens had frozen, so I could not get a drift reading. George Forero and I took the thing up into the cabin and took it apart to clean the lens. We got it back together and back in place, so I was able to determine the wind. With the wind and the airspeed we had, we were going to be 30 minutes short of the coast at Gander. Joe had alerted Search and Rescue of our problem and they were sending out a "Dumbo" B-17. We established radio contact and they said, "We now have you in sight." They were east of us and they told us to turn around and follow them. At this point, we were just coming in sight of land, so we thanked them for their help and proceeded into Gander to land. Thank God for the hundred gallons of "grandma gas" [extra fuel] Joe always put on board!

We got the plane in the hanger and the mechanics changed the prop governor. Now we can still be home for Christmas. Guess what, Gander had had a heavy snow storm. The runway was open but the ramp behind the hanger door was closed. No problem; old barn-stormer Joe had them push the plane back out and clear of the door and started the engines. The prop governor worked fine, so Joe had them chock the wheels, stood on the brakes and put on full power. He blew that ramp clear in about 30 seconds. Out to the runway, back in the air and we are going to make it home in time. But wait, does anyone remember Christmas 1947 in New York? Right, BLIZZARD! When we got overhead LaGuardia, it was closed so we went to Washington and gave up the flight. The next day the weather opened up so we finally got home, just a day late. That happened a lot in the "good old days."

by Walter "Jorgy" Jorgensen

I certainly remember Dec. 24th, 1947. That was just about as rough as things got; certainly a helpless feeling with an ungovernable prop. Every time we hit the feathering pump switch, the prop actually went to a finer pitch and speeded up. A baffling problem with no possible fix in the air. We had to drop airspeed to keep the prop from flying off. I still have my logs from those early days. Checking the log, I find we were in the air 14 hours and 10 minutes, making it the longest DC-4 flight I ever made!

It is impossible at this distant time to figure out how it was that we had enough fuel to make it. I have an idea that Gander was marginal and Joe ordered me to on-load fuel, as much as we could carry since he might be forced to over-fly Gander and go to an alternate. "Home for Christmas" was the objective. I don't remember if this is so but I thank our lucky stars that we uploaded enough "grandma" to make it with this unforeseen emergency.

At Gander we pulled the prop dome to try to find out what was wrong. The distributor valve which is normally screwed into the end of the prop shaft appeared to be missing. We found it inside the prop dome! It had been installed, but never safety-wired into place. As a result, it gradually backed out and finally fell off. What this meant was that all the governor oil plus the Feathering pump oil was being shunted to the low side of the piston, thereby slamming the prop blades into low-pitch. We screwed the distributor valve back into the prop shaft and safety-wired it into place. Then we re-installed the dome. We also did a compression check and changed the plugs just in case they got fouled in the over-speeding. We did an engine run and the prop responded to the prop governor control normally.

This hair-raiser was caused for the want of about 2 cents worth of safety wire! When we finally got to New York, I asked to see the inspector who had signed off that prop installation. Lockheed Aircraft Service out at MacArthur Field did our maintenance. I never got a response. The records appear to have been lost, misplaced, spindled or mutilated.

Ed. A runaway propeller was extremely dangerous. It was due to a mechanical failure that caused the propeller blades to turn flat to the wind which would spin the propeller at very high rpm like pinwheel. Eventually, either the propeller would break off or the engine would overheat and self-destruct. In the first case, the propeller might rip into the fuselage or fuel tanks. In the second case, there might be an engine fire. Turning the engine off did not solve the problem. If control over the propeller could not be reestablished, it was necessary to land as soon as possible.

Originally published in SPAR newsletter, September, 1997

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