Power Settings ?

[scottb613 1,188]

Hi Folks,

Anyone know some realistic power settings for climb and cruise ?

The old rule of thumb doesn’t seem to apply here where you always keep Prop RPM above Manifold Pressure - since the Navajo goes so high on Manifold Pressure... What do the blue areas on the RPM and Manifold Pressure Guages indicate ?

Thanks...

Regards,

Scott

[Les Parson 99]

Hi Scott, 

Per the PA31-310 POH Section 4 Normal Procedures CLIMB:

MAX Normal Operating Power (when safely clear of obstacles or terrain):

39.5" MP 2400 RPM; Mixture (28 GPH min, 475 CHT Max, 1450 EGT Max) LEAN.

I can't locate my PA31 cruise info at the moment, however, I highly recommend the post "PA31 review by from PA31 pilot" by 'acdelta57', dated August 5, 2015. It is highly detailed and provides a wealth of information including cruise settings. 

[scottb613 1,188]

Hi...

Thanks so much - at least I have something to start with - I’ll look for the post - much obliged...

Regards,

Scott

[whamil77 183]

On 11/11/2017 at 11:58 AM, scottb613 said:

Hi Folks,

Anyone know some realistic power settings for climb and cruise ?

The old rule of thumb doesn’t seem to apply here where you always keep Prop RPM above Manifold Pressure - since the Navajo goes so high on Manifold Pressure... What do the blue areas on the RPM and Manifold Pressure Guages indicate ?

Thanks...

Regards,

Scott

It's been 35 years ago, but I have about 400 hours in the airplane.  Normal climb power is 35" MP, 2400 RPM, lean to 24 GPH per engine.  In the sim, you can't get 24 GPH at that power setting so the leaning is not needed unless you increase the fuel flow scalar.  That might give you unreasonably high fuel flows in cruise, however.  Also, takeoff with cowl flaps open, reduce them to half for the climb, and close once leveled out in cruise ( I think the sim only allows full open or full closed). 

[scottb613 1,188]

Hi Bill,

Thanks so much for your personal insights - at least I’ve got some idea of proper operation...

Regards,

Scott

 

 

[whamil77 183]

19 minutes ago, scottb613 said:

Hi Bill,

Thanks so much for your personal insights - at least I’ve got some idea of proper operation...

Regards,

Scott

 

 

Here is a treasure trove of performance data for the Navajo C.  The engine in question is the Lycoming TIO-540-A2C. 

https://www.manualslib.com/manual/1264912/Lycoming-Tio-540-A2a.html?page=41#manual

I think I remember a cruise power setting that we used for max economy of 30" MP, 2200RPM, leaned to 12 GPH (50 degrees lean of peak not to exceed 1650 degrees).  It was approximately 55% power and the only power setting where Lycoming allowed leaning to the lean side of peak EGT. 

[scottb613 1,188]

12 hours ago, whamil77 said:

Here is a treasure trove of performance data for the Navajo C.  The engine in question is the Lycoming TIO-540-A2C. 

https://www.manualslib.com/manual/1264912/Lycoming-Tio-540-A2a.html?page=41#manual

I think I remember a cruise power setting that we used for max economy of 30" MP, 2200RPM, leaned to 12 GPH (50 degrees lean of peak not to exceed 1650 degrees).  It was approximately 55% power and the only power setting where Lycoming allowed leaning to the lean side of peak EGT. 

Hi Bill,

Thanks for the info - I'll read through it...

I'll probably steer clear of LOP - LOL - I'm not paying $6.00 gal for virtual Avgas so I can afford ROP operations... Nice to know though... I've never really looked at the Carenado engine monitors in detail - are they plausible with their indications or merely eye candy ?

Do you personally like Carenado's Navajo implementation ? I recall some other RW pilot seemed to rate it fairly high in a well written post - which influenced my purchase decision...

OBTW: Still flying your DA conversion on the Cheyenne - once again - thanks so much...

Regards,
Scott

[whamil77 183]

1 hour ago, scottb613 said:

Hi Bill,

Thanks for the info - I'll read through it...

I'll probably steer clear of LOP - LOL - I'm not paying $6.00 gal for virtual Avgas so I can afford ROP operations... Nice to know though... I've never really looked at the Carenado engine monitors in detail - are they plausible with their indications or merely eye candy ?

Do you personally like Carenado's Navajo implementation ? I recall some other RW pilot seemed to rate it fairly high in a well written post - which influenced my purchase decision...

OBTW: Still flying your DA conversion on the Cheyenne - once again - thanks so much...

Regards,
Scott

I very much like Carenado's Navajo.  The FDE, when tweaked a little, is reasonable.  The engine sounds are scary accurate.  The MP/RPM combinations are pretty good.  But the fuel flow numbers are not correct, especially on takeoff and climb.  After monkeying with several airplanes and their fuel flows, I have come to the conclusion that the simulator is the limitation, not the add-on.  You can get fuel flows correct in one regime only.  Everywhere else they tend to diverge from reality.  There doesn't seem to be a way to modify the sim's native fuel flow curves.  So....pick the spot you want them to be accurate and live with inaccuracy everywhere else. 

[scottb613 1,188]

Hi Bill,

Good enough for me - thanks for the insights...

Regards,
Scott

[CW46 101]

I think it is a good model and one of my favorite's in P3D to fly, the systems are not completely functional but I have no issues with it otherwise. I had around a 900 hours between the Chieftain, the short 310 version and a short model Panther conversion with the 350 HP engines.The Panther absolutely rocked, great climb performance and much improved single engine operation. It felt and sounded like a turbo prop in cruise with the Q-tip props and a sychrophaser. When I did the Panther demo flight at light weight we were able to attain 800 fpm with one engine shutdown and that pretty well sold me on getting the conversion done.The demo pilot was authorized to demonstrate a solo only, single engine touch and go.We landed I got out and he proceeded to do a normal takeoff, shut one down in the pattern and then did the touch and go.Very impressive display of performance capability.

[scottb613 1,188]

Hi Gary,

Thanks as well - always nice hearing from the real deal...

Yep - can't say I've ever seen a twin do a single engine TNG... Pretty impressive...

Had a guy at my home drome try a single engine takeoff in a Cessna 337 - he's - umm - no longer with us...

Regards,
Scott 

[scottb613 1,188]

13 minutes ago, CW46 said:

I think it is a good model and one of my favorite's in P3D to fly

 

[CW46 101]

Oh yes, the C-337 flew like a heavier C-182. You always lead with the rear engine on takeoff to verify it is putting out power then follow with the front engine.That was the first thing I was told about it for a takeoff, those little tricks keep you alive.