Prop Damage

[Zebedee]

I have dings in both of my prop leading edges. More than I feel I should. Maybe I'm just unlucky or my home airport has more than its fair share of loose stones. (true)

Or maybe the MT wooden prop with its nickel leading edge is not as tough as Hartzell

I can't help but wonder if the ECU test and static run up at takeoff to check for max power are also not contributing factors.

Surely applying power slowly and confirming full power by 60kts is the same thing. Maybe the turbos kicking in is the reason, but you get the same thing on touch n go's and its vey manageable.

Does everyone runup power to max before brake release?

I not, what do you do?

Thanks

JIm

[ememic99]

…static run up at takeoff to check for max power…

Why would you do this on normal takeoff if there’s sufficient runway available for stop in case loss of power / no sufficient power developed during ground run?

Does everyone runup power to max before brake release?

Only for short field takeoff.

[Soareyes]

Are the leading edges made of nickel or stainless steel? In 2021 I spoke with someone from MT who said all their props had nickel, except for the ones on Austro engines.

[Zebedee]

My DA62 transition instructor taught me to do all takeoffs holding brakes and checking full power prior to brake release.

This video shows that at 4min 20secs
https://www.youtube.com/watch?v=xegFTDgroZg&t=11s

Here at 6.46
https://www.youtube.com/watch?v=ctgzb2SDq4Y

Here at 2.18
https://www.youtube.com/watch?v=CzPjSasTFJ4&t=22s

AFM under normal takeoff did not show anything about holding brakes.

Of course there are multiple videos without holding the brakes.

The procedure is coming from somewhere, just wondering where.

Thanks

Jim

[Ed McDonald]

In addition to avoiding prop damage, a rolling take-off allows the aircraft to have more speed and more air going over the rudder before full power (and torque) is achieved, thus reducing the amount of foot work required on take-off.

[Chris]

Does everyone runup power to max before brake release?

If not, what do you do?

I only hold the brakes that long on short(ish) runways. Most of the time I'm operating from runways over 4500' and either perform a rolling start from the taxiway or release the brakes as the power passes 50%. I feel that the MT props are a little more fragile than the Hartzell ones when it comes to damage from picking up loose gravel, though I don't have any way to measure that.

The ECU test doesn't get close to max power, so I'm generally less concerned about those.

[ememic99]

The procedure is coming from somewhere, just wondering where.

Strange stuff can come from various sources, some can be passed over generations of instructors although they are absolutely wrong. My favorite one is a myth of ice bridging on pneumatic deicing boots. It used to be problem on very first generation of these devices but there are still instructors who teach and pilots who believe this. And there was at least one accident due to late deicing activation due believing this nonsense.

[michael.g.miller]

My DA62 transition instructor taught me to do all takeoffs holding brakes and checking full power prior to brake release.

As you pointed out, this is certainly not SOP per the AFM. I would only hold the brakes on short runways, since you want to validate proper operation of the engine. Usually ECU failures happen a few seconds after full power, so on a short runway, you want to be sure you have time to pull power back and abort.

Static takeoffs significantly increase wear on the propeller (due to debris), and subject the engine to high power with low cooling. Certainly not an ideal operating environment unless necessary due to runway length.

Does the instructor have significant Diamond time?

[MikeMeadows]

Are the leading edges made of nickel or stainless steel? In 2021 I spoke with someone from MT who said all their props had nickel, except for the ones on Austro engines.

MT website says "The metal leading edge can be manufactured from stainless steel or optionally chemically from Nickel.” In the DA62 POH, it states on page 7-32 "Each propeller has wood composite blades with fiber-reinforced plastic coating and stainless steel edge cladding. Also, Ewing does state on page 68 of his DA62 iBook “Outer edges protected by stainless steel cladding"

I teach stainless, not nickel.

Mike Meadows
CFII MEI
Houston, TX

[Zebedee]

Thanks for all the insight. Lots of good info here.