[Laird]

Recently spied at an open hangar in Socal.

Great example of strain gauging a propeller to do vibe testing. Note the large black hub forward of the propeller. It's the data collection and transmitter unit. Transmits sensor data to a laptop in the passenger seat.

Great to see Hartzell go to this level of testing.

Laird

 

[Full Throttle]

Does he have a special spinner on that prop so he can fly it, or is it just for ground runs...?

 

[Laird]

Does he have a special spinner on that prop so he can fly it, or is it just for ground runs...?

I don't believe he has a special spinner so I "think" that they're testing without a spinner, but I don't know for sure.

I don't have many details beyond what I see in the picture.

 

[BillL]

Looks pretty standard testing for Hartzell. They gave me a tour of the factory when I was selecting props (10 yrs ago) and there was one in a test cell instrumented like this. Maybe we are just seeing the testing on experimental. Although, it sure would be nice to see a good efficient speed optimized composite from Hartzell for the RV and Rocket speeds. The BA aluminum prop is really good!

 

[Freemasm]

I don't believe he has a special spinner so I "think" that they're testing without a spinner, but I don't know for sure.

I don't have many details beyond what I see in the picture.

Can never be 100% sure for a test set-up but in general, the spinner is needed for flight. Uneven, inadequate, engine cooling flow is pretty much guaranteed; air not properly directed towards inlets/cylinders, "cooling" flow being allowed to bypass the inlets through spinner opening and raise Ps downstream of cylinders, etc.

 

[DanH]

Probably the round thing, lower right, by the cowl. Part of it anyway.

 

[Taltruda]

Probably the round thing, lower right, by the cowl. Part of it anyway.

To me, that looks like a bucket to lay the prop down on..

 

[DanH]

I think you're right!

 

[Kahuna]

Can never be 100% sure for a test set-up but in general, the spinner is needed for flight. Uneven, inadequate, engine cooling flow is pretty much guaranteed; air not properly directed towards inlets/cylinders, "cooling" flow being allowed to bypass the inlets through spinner opening and raise Ps downstream of cylinders, etc.

I have done several of these tests with Hartzell on RV's. No spinner.
I ran my plane for a year no nose spinner due to cracking in my 'screwless spinner'. There was no difference in cooling what so ever. I took a lot of data on this.

 

[Freemasm]

I have done several of these tests with Hartzell on RV's. No spinner.
I ran my plane for a year no nose spinner due to cracking in my 'screwless spinner'. There was no difference in cooling what so ever. I took a lot of data on this.

Would be a big-time violation on most (all?) certified aircraft whose TCs were from the last several decades. Don't know your baffle arrangement behind the spinner/cowling but It implies you have a fairly large amount of cooling air margin. First guess would be "excess" exit area. Some cooling drag improvements could be realized by optimizing the exit. Some spit-balling during lunch

 

[Laird]

Inquiring minds what to know....

Anybody have any idea what BLADE that is that they're testing? It is composite.

 

[Freemasm]

Guessing so based solely upon what appears to be leading edge guard.

 

[TParker]

Does he have a special spinner on that prop so he can fly it, or is it just for ground runs...?

There is a "spinner" cap that goes on the front of the telemetry unit; doesn't cover up the hub or the unit like a typical spinner would. Testing is conducted on the ground and in flight.

 

[BillL]

There is a "spinner" cap that goes on the front of the telemetry unit; doesn't cover up the hub or the unit like a typical spinner would. Testing is conducted on the ground and in flight.

Thanks for weighing in Trevor and setting the record straight!

 

[TParker]

Missed this question:

Anybody have any idea what BLADE that is that they're testing? It is composite.

The test article is a composite blade configured for the Lancair 360; current designation for the blade is NM7504-5(). The () is filled in with an engineering prototype designation for now, which may or may not change as the final nomenclature is TBD. The configured diameter is 70".