Comments on: Man vs. machine

By: harrier

harrier — Sat, 13 May 2006 22:29:05 +0000

Different plane with a different trim system but trim experience none the less. I was in a Seneca and had trimmed it nose low for some maneuver I was practicing. When I tried to trim the nose up, I heard a snap and the wheel started free wheeling. I looked down to see the cable hanging loosely. Now, I had already purchased a gym membership for the sole purpose of gaining enough arm strength to land the Seneca with just one hand. The plane is NOSE heavy on landing and we had a tiny strip, so you aren’t going in with much power to help you out. Luckily I had another pilot with me. He held the nose up with both hands, his feet braced against the panel (it took this much to override that trim, and he kinda had geek arms) as I landed. When maintenance pulled the cable out, it was FINE in all spots but one wear spot where it had obviously been rubbing against something.

It was just another experience that makes you realize no matter how much you preflight, you gotta be ready for anything. I imagine if I had been alone, I would have diverted to the big 10,000′ runway at the nearby international airport.

By: John

John — Sat, 13 May 2006 00:03:34 +0000

A 1969 Arrow I used to instruct in had a similar issue. During one flight with another instructor, I found the trim had become very stiff. The other instructor wanted to fiddle with it, but I was in the middle of an approach and thought this was a bad idea. So I just used a little force on the yoke to fly the approach.

On the ground, we squawked it and I happened to talk to the mechanic a day later. The trim cable that wraps around the jack screw had slipped over time and a turnbuckle had move int a position where it was binding against one of the plastic pulleys. Had we continued to run the trim back and forth, the pulley could have split, the cable gone loose, and we would have lost trim control.

By: Paul

Paul — Thu, 27 Apr 2006 03:06:26 +0000

Wild story, Dave. So the anchor point for the anti-servo tab was just flexing? I guess elevator effort has eased up a bit?

I know that I get tougher elevator trim effort in the cold months, but I chauked it up to bad lube on the lead screw. Good you caught this.

–paul