Hartzell Trailblazer Comp for M5-180
Posted: Wed Sep 22, 2021 3:46 pm
Guys,
I'm new to Maule ownership but have been flying them for some time. (41years!) I currently own a pristine 87' M5-180C. Previously I owned 2 RVs (4,6) I built and my RV4 was a test aircraft for Craig Cattos early composite designs. I became a huge fan of the type and a recent trip to OSH and seeing all the new 0-360 powered Huskies with 2 blade Hartzell Composites out front got me thinking. Why not have this on an M5-180?
So I contacted my good friend Les at Hartzell who in turn hooked me up with Trevor Parker. Here's what Trevor had to say:
Hi Smokey,
Les asked me to respond to this for you.
That composite propeller (HC-C2YR-1N/NG8301-3, marketing calls it a Trailblazer) is likely a good performance match to that airframe and mission. There are three paths to installing the prop on the aircraft:
1) Via STC
a. There currently isn’t an STC to install the composite prop (or a version of it) on the M-5-180C
b. Creating an STC is costly and time consuming and, unfortunately, the market for the M-5-180C is small due to the limited number of aircraft so to my knowledge we don’t currently have any plans to pursue an STC for this installation.
2) Via field approval
a. A field approval is a bit simpler in terms of process as compared to an STC, but still needs to address the regulations. This can be done in coordination with the FSDO or an appropriately qualified DER.
3) Via experimental category
a. The aircraft could be placed into an experimental category, i.e. R&D, for a limited time to perform testing. This limits the utility of the aircraft during time in the category based on the operating limitations, and isn’t typically a long term solution.
Either an STC or a field approval for this installation would require a fair amount of testing and effort. Two things that make this application complicated are the diameter and noise. The Husky uses an 80” diameter version of the propeller. The TC for the M-5-180C only approves the use of a 76” prop, and I can’t find any STCs that install a larger diameter propeller to use as a comparison. Currently, a 76” diameter version of the composite propeller is not vibrationally approved with the O-360-C1F (or similar) engine. Several larger diameters are approved on the engine, but increasing the diameter used on the airplane impacts noise and ground clearance. Ground clearance is fairly straight forward and can be measured to show it meets the requirements (assuming it would), but it’s another step. Noise is impacted by a change of propeller and needs to be addressed even if the diameter stays the same; given the particulars, it’s unlikely that this could be addressed via analysis especially if the diameter increases. In order to test, there needs to be performance information available in order to determine the test condition; if the flight manual for the M-5-180C is like the other Maule flight manuals I’ve seen, this information doesn’t exist and would have to be generated via flight testing.
If you wanted to test it yourself, you’d have to acquire a propeller and work with a DAR to put the aircraft into experimental and back into standard category when you were done.
I hope this helps, please let me know if I can be of further assistance. Trevor
Undeterred I'm continuing the investigation into getting one on my M5 for testing.
I'll keep the group posted!
V/R
Smokey
I'm new to Maule ownership but have been flying them for some time. (41years!) I currently own a pristine 87' M5-180C. Previously I owned 2 RVs (4,6) I built and my RV4 was a test aircraft for Craig Cattos early composite designs. I became a huge fan of the type and a recent trip to OSH and seeing all the new 0-360 powered Huskies with 2 blade Hartzell Composites out front got me thinking. Why not have this on an M5-180?
So I contacted my good friend Les at Hartzell who in turn hooked me up with Trevor Parker. Here's what Trevor had to say:
Hi Smokey,
Les asked me to respond to this for you.
That composite propeller (HC-C2YR-1N/NG8301-3, marketing calls it a Trailblazer) is likely a good performance match to that airframe and mission. There are three paths to installing the prop on the aircraft:
1) Via STC
a. There currently isn’t an STC to install the composite prop (or a version of it) on the M-5-180C
b. Creating an STC is costly and time consuming and, unfortunately, the market for the M-5-180C is small due to the limited number of aircraft so to my knowledge we don’t currently have any plans to pursue an STC for this installation.
2) Via field approval
a. A field approval is a bit simpler in terms of process as compared to an STC, but still needs to address the regulations. This can be done in coordination with the FSDO or an appropriately qualified DER.
3) Via experimental category
a. The aircraft could be placed into an experimental category, i.e. R&D, for a limited time to perform testing. This limits the utility of the aircraft during time in the category based on the operating limitations, and isn’t typically a long term solution.
Either an STC or a field approval for this installation would require a fair amount of testing and effort. Two things that make this application complicated are the diameter and noise. The Husky uses an 80” diameter version of the propeller. The TC for the M-5-180C only approves the use of a 76” prop, and I can’t find any STCs that install a larger diameter propeller to use as a comparison. Currently, a 76” diameter version of the composite propeller is not vibrationally approved with the O-360-C1F (or similar) engine. Several larger diameters are approved on the engine, but increasing the diameter used on the airplane impacts noise and ground clearance. Ground clearance is fairly straight forward and can be measured to show it meets the requirements (assuming it would), but it’s another step. Noise is impacted by a change of propeller and needs to be addressed even if the diameter stays the same; given the particulars, it’s unlikely that this could be addressed via analysis especially if the diameter increases. In order to test, there needs to be performance information available in order to determine the test condition; if the flight manual for the M-5-180C is like the other Maule flight manuals I’ve seen, this information doesn’t exist and would have to be generated via flight testing.
If you wanted to test it yourself, you’d have to acquire a propeller and work with a DAR to put the aircraft into experimental and back into standard category when you were done.
I hope this helps, please let me know if I can be of further assistance. Trevor
Undeterred I'm continuing the investigation into getting one on my M5 for testing.
I'll keep the group posted!
V/R
Smokey