Prop Damage

[Zebedee]

I found this in performance section


If brakes are not held while applying power, distances apply where full power setting is complete.

[tjmoody]

Interesting discussion! I am in the camp of applying full power and checking engines before releasing brakes in my Austro DA42. This thread led me to go back and look at the POH. I had been under the assumption that the POH mandated a full power check prior to rolling but I agree that it is not definitive. The POH does require that "proper and symmetric performance of the engines at MAX" is verified but this can be done early in the take off run. FWIW the Diamond Flight Training systems training document I received from LifeStyle when I purchased my plane is more definitive and does list a Max available power check after lining up on the runway.

I get the arguments made here for not doing a max power before releasing the brakes. However, I like being able to fully check the engine gauges prior to the plane starting to roll. I'd suggest that is a modest safety benefit.

[ememic99]

I'd suggest that is a modest safety benefit.

I’m sorry but I don’t see any safety benefit in max power before releasing the breaks.

[mfdutra]

I agree with Emir. I apply power very gently as I'm rolling, mostly to catch any asymmetry early and stay in sync with the rudder. I still have plenty of time to make sure both engines are producing the expected output.

If there's anything really wrong with the engine, you will get an ECU FAIL anyway.

[Karl]

Static RPM is usually checked with the aircraft stationary.

As the aircraft moves fwd the load on the prop blades changes as the airflow is at a different angle of attack.
The only time you will get consistent readings is with the aircraft stationary and of course little or no wind.

With the aircraft held on the brakes, you can check the engine indications at your leisure, doing it during the takeoff roll it is probably limited to a quick glance. Of course with G1000, digital instrumentation, and FADEC it is much easier than the older analog systems that required us to spot problems by actually reading the gauges.

[neema]

Rolling takeoffs are the number one technique to mitigate FOD on props and jets. If you don't need a static takeoff, do a rolling takeoff.

Look under the props when you do a run up in the wet. The little vortex tells you what's going on, and that's with power at 50%/lower RPM.

Imagine full power.

[Nikandsteve]

Let me just say a rock chip on the leading edge is an 8k repair at American Propeller Service and it takes time! Go carefully all.

[Rich]

Let me just say a rock chip on the leading edge is an 8k repair at American Propeller Service and it takes time! Go carefully all.

It can be. It depends on the extent. I had one like this that was just barely bad enough to require this treatment and it was this expensive when including shipping - in 2002. Insurance covered it. None since. But I don't do max RPM runs, either.

Once I had a Tri-Pacer stuck in its "grass" tie down spot. I revved the engine to full power to get it out. After flying, when I shut it down both blades had big chunks taken out of them. Think half-moons with about 1/2" diameter. No repairing this prop by any means - totally trashed. This was a fixed-pitch aluminum propeller, lest you think that these are not equally vulnerable.

[Nikandsteve]

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Let me just say a rock chip on the leading edge is an 8k repair at American Propeller Service and it takes time! Go carefully all.

We didn’t submit to insurance because our agent said claims follow you for 5 years!? Not sure if that means they follow the aircraft or the insured and was worried about future rates being impacted. In hindsight it was a lot of money for a rock chip