comm. rating

[Ryan]

Just started my comm and have a few questions about throttle/prop/mixture control. BTW its in a Piper Arrow.

I understand having all three forward on T/O, this makes sense. I also understand throttle back to 24"/2400rpm at cruise and back on mixture to 10gpm.

Im a little confused though on landing. Throttle comes back to 15"( I get that) but prop to full forward? Is this done just in case of a go around?

Also, just say for instance my instructor becomes incapacitated(God forbid) and I cant remember what to do with the prop/mixture would I damage anything or get myself into trouble just by leaving everything full forward?

Im sure after a few more lessons this will all make sense Im just a little lost right now. Thanks

 

[mayday1]

keep your prop rpms higher than your manifold pressure setting -- i.e. you don't want to overstress the engine by having a higher manifold setting than your prop setting.

and obviously you don't want your throttle full forward to land. The props full forward on landing is made in case of a go around. Also the full forward setting of the props will increase drag, and add a little to your descent as well.

 

[moxiepilot]

Im a little confused though on landing. Throttle comes back to 15"( I get that) but prop to full forward? Is this done just in case of a go around?

yes

Also, just say for instance my instructor becomes incapacitated(God forbid) and I cant remember what to do with the prop/mixture would I damage anything or get myself into trouble just by leaving everything full forward?

probably not.

Im sure after a few more lessons this will all make sense Im just a little lost right now. Thanks

good luck

 

[Goose Egg]

Just keep 'em both in the green arc. Probably wouldn't hurt you to look in the POH either.

-Goose

 

[Ryan]

Just keep 'em both in the green arc. Probably wouldn't hurt you to look in the POH either.

-Goose

I agree with you 100% about looking in POH. Im in the nuclear power field and its all about procedural compliance. Im just one of those people that needs something explained to me and to understand it before I can remember it.

 

[troy]

check out the performance section of the POH and look at the Manifold pressures vs. the RPM section. You will begin to see a relation between the two, and you will be good to go if you stick to what the manufact. says. As a rule of thumb, you do not want to "oversquare", as in lots of throttle/MP and little RPM's. You can relate this to a manual transmission of a vehicle. It will not be good to be in 4th gear, 10mph and full throttle.
Props go forward on landing in case of a go-around. They also act as a "brake" to help you slow down on final. Do you notice it when pushing the prop forward? If you were to lose an engine, you could pull the props out, and get a slightly further glide, also.

 

[Lear60Guy]

I use all 3 full forward for takeoff, 25"/2500rpm for climbout, and 21"/2400rpms for cruise in the non t-tailed version..... If you look in the chart in the POH there are actually settings that have you keep the throttle on top of the prop, Its definitly harder on the engine though.

 

[TheChief]

would I damage anything or get myself into trouble just by leaving everything full forward?

Im sure after a few more lessons this will all make sense Im just a little lost right now. Thanks

Just don't jam everything forward quickly...I hear it's rough on the governor

 

[illinipilot]

I've heard the "oversquared" rule, which I guess is playing it safe if you don't know the airplane. Look in the POH though and I'm pretty sure the arrow has some power settings that or "oversquared." In a turbocharged a/c it can be way "oversquared." I the Navajo for instance I think we used 38'/2400 or something like that for climb, and 33'/2400 cruise.

 

[Yellow Snow]

The oversquare stuff you hear is not necesssarily true. It came from years ago and applied to radials. If you look at the poh on a seneca, arrow, baron, 206 etc etc you will see plenty of oversauare settings as these are fuel efficient. The props are forward on approaches because if you had to go around and jammed the throttles to the stops with the props at 2100 you'd blow the cylinders off, especially on turbocharged engines.