337 autopilots

[SteveG]

I'm quite surprised to read of so many unhappy S-Tec users. I have the older Model 50 and it holds heading and altitude +/- virtually nothing. Occasionally, in turbulence, you'll want to "help" it dampen the initial jolt but it then recovers nicely. I have never seen any tendency to porpoise or hunt. My only negative comment would be that its approach mode is insufficiently sensitive to accurately track a localizer, wandering +/- a half dot or so. I just fly the approach on the heading bug with no problem so it's not any real concern. Assuming the guts of the system are essentially the same across the differing models being discussed, I would have to conclude that precision problems are installation problems or rigging problems based on my experience with the make.