Has anyone installed a 2 blade MT prop on a spring gear M7-235-C O-540-B4B5. If so any chance of getting a copy of the 337 used for the field approval.

Thanks

Larry Schlasinger does the field approvals for MT props 612-six one nine 57 eight two. There is a cost involved might be worth a call.

I have the 3 blade MT on my M7-235C . John Nielson at MT took care of getting all the paperwork done. Either Larry or John should be able to help you.

Have you considered the Hartzel trailblazer the have both two and three blade versions that are stc for the Maule. The two blade came in a bit cheaper for me and no field approval expense. I think the performance is pretty close I can’t give you an apple to apple comparison because I added bushwheels at the same time. The 29’s only cost me a couple of knots so I think it was a wash between the prop and the tires. It will save some weight also good luck let us know .

Plus the Hartzell allows you to use your existing spinner doesn’t it? Assuming you have the stock Hartzell installed?

Been thinking of making the change and that tipped the balance towards the 2 blade Hartzell for me.

(The Other Kirk)

captnkirk wrote:Have you considered the Hartzel trailblazer the have both two and three blade versions that are stc for the Maule. The two blade came in a bit cheaper for me and no field approval expense. I think the performance is pretty close I can’t give you an apple to apple comparison because I added bushwheels at the same time. The 29’s only cost me a couple of knots so I think it was a wash between the prop and the tires. It will save some weight also good luck let us know .

I was interested in the trailblazer but it is not STC'd for my engine (O-540-b4b5) 2575 rpm for takeoff. So it would also require a field approval.

I was unaware of that difference. Did you check with Hartzel they may help with the process .

captnkirk wrote:I was unaware of that difference. Did you check with Hartzel they may help with the process .

Yep, I emailed them. Their response was STC doesn’t include the B4B5 engine have a nice day. There was zero interest from Hartzell in helping to facilitate the installation of a trailblazer on my Maule.