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Greetings all - first post on the forum!! Apologies if I missed anything specific on this - I searched and saw a thread from about a year ago or less discussing setting prop pitch on a 912iS. I am about to pick up a Tecnam Astore with the 914 engine (almost new, <100 TT). I understand from the prior thread that Roger recommends setting the pitch for a WOT at about 5600 RPM.

It's unfortunate, of course, that here in the US our LSA's are required to have either a purely fixed pitch prop or a ground-adjustable prop. The Tecnam 914's come with the 3-blade Sensenich ground adjustable prop ... I know that there are a few P2008 turbo owners and prospective owners who have the same question.

How best to set the pitch? I'm assuming that you would set it for 5600 (?) RPM at 100 HP output rather than the 115 HP output that you can only run for 5 minutes ...

Any suggestions would be helpful. I'm picking the aircraft up in early July and plan to have my Rotax person here in Houston take a look at the pitch when I get home and would like to be able to give some guidance at that time (he will check the balance as well).

Thanks in advance!
  • Re: Setting ground adjustable prop pitch for 914...

    by » 4 years ago


    Hi Joel,

    The 914 is best run with an in flight adjustable prop and it is a shame here in the US we can't do that. So since we're stuck with only a ground adjustable prop you need to pick a pitch that will give you a good balance between climb, cruise and fuel economy. That rpm is 5600-5650 @ WOT. Higher or lower than that you begin to shave off either end of performance. You get to keep some of your HP & performance with the 914 over the 912, but you still don't want to apply any more stress or heat build up if you try to over pitch.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-574-1080 Home (TRY HOME FIRST)
    520-349-7056 Cell

  • Re: Setting ground adjustable prop pitch for 914...

    by » 4 years ago


    Thanks Riger that was my guess as well. I assume WOT for this scenario is at 100 hp not 115? Just trying to figure out what that means on a 914 aircraft. The Tecnams have a detent in the throttle that takes you from 100 to 115 hp for the 5 minute limit, at about 40 inches of MP as I recall.

    Sounds like the pitch would be about what it is on a 912iS model then. I'm new to this so apologies if I sound like an idiot! I just want to ask the right questions and give the correct guidance to my Rotax guy.

    Thanks!!

  • Re: Setting ground adjustable prop pitch for 914...

    by » 4 years ago


    Hi Joel,

    I truly believe there is no stupid questions so ask away.

    I would set the pitch for the 100 hp normal cruise operations. You most likely will use the added hp on takeoff when the engine rpm is lower at WOT anyway so then it would fit right in to increase that rpm.
    A non adjustable inflight prop may tie our hands some, but it's workable.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-574-1080 Home (TRY HOME FIRST)
    520-349-7056 Cell

    Thank you said by: Joel Mack

  • Re: Setting ground adjustable prop pitch for 914...

    by » 4 years ago


    Thanks that's the guidance I needed! I'm sure I will have more questions later and really appreciate all the wisdom on this forum and the quick responses ...

    One more question: I've seen on a couple other forums that you can't run a 914 LOP. I know the 912iS has an "eco mode" which is basically LOP as I understand it; but assuming you set the prop pitch for 5600-5650 RPM ... and you want to improve cruise fuel economy, can you run the 914 LOP and if so what RPM (and other criteria, CHT or EGT) should we be looking for?

    Cheers!

  • Re: Setting ground adjustable prop pitch for 914...

    by » 4 years ago


    "...That rpm is 5600-5650 @ WOT. Higher or lower than that you begin to shave off either end of performance..."

    Roger,

    Sorry but I'm confused about the specifics. (I don't have a 914. Mine is a 912ULS.) At what airspeed are you recommending 5600-5650 RPM at WOT or is that a static ground run at 5600-5650? Currently at WOT my RPM will exceed 5800 in level flight if I leave it there. So I have to pull the throttle way back to keep it at or below 5500 RPM. And I cruise at 5350-5400 so altitude excursions don't allow it to exceed 5500.

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