When do you go to low RPM on landing?

[Adam Frisch]

This is one of the areas I'm not sure I've been correctly taught in. If I'm not using reverse, I tend to go to low RPM as soon as I can after touchdown, to kill residual thrust. But when I looked at a few older clips on YouTube about operating the TPE, it seems they recommend doing that after clearing the rwy. But in my aircraft, the thrust at high RPM is considerable even at idle power, so I tend to not want to do that. What's correct?

[appleseed]

Are you saying You don't go into beta at all sometimes after landing?

On a related note, If I am stopped with nothing behind me to worry about prop blasting I do bring power levers over the gate and out of beta. I was waiting for a clearance one evening, parking brake set underneath a light  that was flickering at a frequency that allowed the prop blades to become visible, and they were oscillating freely through a surprising pitch range that looked like it would wear things out at a higher rate than when we came out of beta and put positive load on the blades. I used to try to minimize wear on brakes. But now I prefer to not be at zero thrust blade angle. Positive thrust, or negative (rarely actually get into reverse) but not floating in between.

And to answer your question Adam, about 40-60 knots. Not in hurry to drop rpm.
dealing with crosswind, or atc is higher priority. But I always go to flight idle and then Beta at touchdown. I got used to lift dump in jets and I feel like flight idle then beta is the next best thing.

[donv]

I bring them back once things are stable and I'm on the runway and slowing down.

The Merlin used to have a procedure where you didn't bring them back until turning off the runway, but I think that had something to do with the 4-blade props. The Merlin also had minimal reverse (although didn't need much, because the prop discs were so huge even in Beta!).

If you plan on using reverse, as opposed to just beta, keep the RPM in high until you are done, whenever that is.

[Bruce Byerly]

Whatever you do, don’t yank back on the condition levers when anywhere back towards reverse, especially without woodwards.  Bog down is a real risk and pulling the condition levers back after landing is where it’s most likely to happen in my experience.  It’s bad training and has cost a lot of people a ton of money. If you wait until you’re off the runway, that risk is minimized and why that procedure was promoted in my opinion.  I  normally ease them back on rollout after landing but not until things are settled down in ground idle.  At some point in the past I understood the governor protections and functions of the bendix and Woodward FCU’s but I’d need Dave Corwin to explain that again. Avoid bog down. It leads to molten metal out the tailpipes and six figure invoices.

[donv]

Basically, I would say this: if you are landing on a short runway, and yank it deep into reverse, wait until you have slowed to a reasonable speed and you are sure you are not going to run off the runway, then get it out of reverse, and then bring the condition levers back.

If you are landing on a long runway and probably won't use reverse at all, then wait until things are slowing normally and under control, and bring them back.

Some people feel, and I have observed this a bit myself, that in gusty crosswinds, the airplane is easier to control on rollout with the props in low, since there is less effect on the prop disc.

[Adam Frisch]

Good info - that's what I've been doing. I've never been in Low RPM and beta at same time. It was just when to go to idle on a longer rwy with no beta.