I have done a more careful measurement. I used a taut string, carefully aligned with wheel/tire sides. I think it is decently accurate. Attached is the measured geometry. I compute it to be roughly 0.33° of toe in per side, which seems pretty small. The sides are quite symmetrical. And while I didn’t do a second measurement, visually I think it gets straighter with increased fuel weight, i.e. with more compressed strut.

So I think main thing I need to do is figure out whether the strut is at the correct fill or perhaps needs a little less pressure. Which might help with the toe in just a little.

The toe in is probably set to deal with heavy braking which will tend to make the wheels toe out. The idea is to make the tires as aligned as possible during the highest wear condition.

On my Citation, the MM toe in spec is about 0.6 degrees so a zero toe in spec is actually not the target.

Mike C.

I definitely figure it is possible (likely) it is designed in. Maybe less for the heavy braking condition as for heavier weight conditions(?). The Piaggio may have different stiffness characteristics in the gear geometry, but still - optimized for some conditions but not others.

I did run my MU2 struts a hair on the low side and it seemed to help get good tire wear.

Owen takes us along for a nice trip:

[youtube]http://youtu.be/oAEENOLNrOY[/youtube]

I noticed that he turned ON the PROP SYNC on takeoff and OFF again for the landing.
Is that standard procedure?

Takeoff roll = Autofeather ON, prop sync OFF
Through about 130-150 KIAS, Autofeather OFF, prop sync ON (as desired)
Before landing = Autofeather ON, Prop sync OFF

The switches for those are next to each other, I think he did both.

Not a Type Ii Sync?

Uh, yes, Woodward type II synchrophaser.

Checklist procedure in AFM supplement says on during climb checklist and off during before landing checklist.

Does type II imply something else?

Know if prop sync off is a limitation? I thought type 2s can be left on at all times during normal ops. for some reason some manufacturers call out turning them off for takeoff and landing. later MU2s are one example and I always wondered if it was a TPE thing. Wonder why the p180 doesn’t allow it to be left on at all times

I don’t think it’s a limitation. The AFM supplement says no changes to Section 2 limitations, and the checklist procedures I mentioned are in the Section 4 Normal Procedures.

Uh, yes, Woodward type II synchrophaser.

Checklist procedure in AFM supplement says on during climb checklist and off during before landing checklist.

Does type II imply something else?

During training my Piaggio instructor did pretty much say it was no big deal if forgotten and left on.

Prop sync/autofeather discussion made me think of something "prop" related. Not a lot of great run-up spots at home airport. The ramp at FBO is large - I can usually find a spot away from others for prop governer and autofeather checks.

Last week one of the line guys said "Hey, why is it that only you and the Fed's in their King Air do run-ups??" I mentioned I think every King-Air should be doing similar. He just shook his head. Lots of King Airs on that ramp...well known 135 operators. Maybe they do them at the hold short line...but I've only seen noticed them rolling down the taxi-way and taking off.

Coming from the MU-2 it was drilled into me that these types of test are absolutely mandatory - "can't do it/not a good test/can't fly". Maybe not so-much in the PT-6 community?

Short of the overspeed governor, everything else on the MU2 is pretty much done on start up (supplemental NTS check on 4 blades and some little switch tests on SRL versions)

I know some king air operators that do their run ups on taxi against the brakes. Also, don’t forget first flight of the day run ups. Some guys may have done it already.

I find the P180 auto-feather check requires a decent amount of power applied, to the point that when it's cold I often can't get the brakes to hold. Because of that, I do it when I have a decent runup area (do at home airport), but I will allow myself to skip it sometimes in the interest of pragmatism (don't want to end up in the weeds or blow some poor Cessna tumbling backwards, depending on situation). I figure it is unlikely to have broken over just a flight or two. Granted possible, but... playing the odds a little for pragmatism.