Ovation 3 Cruise Power Charts

[GeorgePerry]

Looking for Best Power and Best Economy charts for an ovation 3.  Anyone gott'em?  

[carusoam]

G,

As in the charts that are in the STC document?

Delta Aviation used to have them posted on line at their website.

Looks like it may have been removed.  Probably owned and available through Mooney.

i might be able to email a copy of it to you.  Let me know...

Best regards,

-a-

 

[Deb]

George,

This thread may help: http://mooneyspace.com/topic/18918-need-ovation-3-stc-performance-charts/#comment-279720

 

[GeorgePerry]

Thanks to everyone who forwarded this information...I received the 310 STC chart and was able to pull the Ovation 2 ROP and LOP cruise charts off the web.  Issue is that they don't really match up.  Ovation 2 has power segmented in two charts 50 deg ROP best power and 50 Deg LOP best power and gives power settings at 75% 65% 55% and 45%.

The 310 STC chart is "all in one" with power at Max, 78%, 70%, and 60% with a note that says subtract 8% power for LOP ops.  

 

Almost all of the time I run at 65% LOP.  Good compromise setting for power, temps, fuel flow, and keeps the engine out of the red box. So the STC chart isn't ideal.  Also if you interpolate off of the 70% power from the 310 chart, run LOP and subtract 8% like the not says, you get 62% power, which at 2400 rpm yields 13.3 GPH.  

Compare that to the Ovation 2 chart for LOP at 65% power and at 2400 RPM and it yields 12.3 GPH.  So they don't match.  That said I understand the common denominator is % of rated power so the 310hp from the STC chart and 280hp from the Ovation 2 chart won't be the same.

So what I think I'm going to do is use the 310 charts for TO and Climb and the Ovation 2 charts for cruise and set percentage power accordingly.  I'll use 2400 RPM, 22in MP, 12.3 GPH, Which puts the IO-550 running at 59% of the maximum rated horse power of 310, but 65% of the Ovation2's rated HP of 280.  Clear as mud! 

 

   

[ArtVandelay]

Ovation has a service ceiling of 20000?

[Cruiser]

Look at it this way. The IO550 engine is the same. The STC just adds 30 HP and 200 RPM to the Top End.

When you operate the engine anywhere below the added power and rpm the performance should be the same from the engine's point of view. 

You also changed the prop from two blades to three blades. Besides looking really cool, you will actually loose a little speed in cruise but get a huge boost in take off and climb performance. 

As for the charts, 24 x 2400 or any other combination is going to be identical except for the effect of the propeller change. Remember though the O2 and O3 charts are based on 280 HP. and 2500 max RPM. not 310 HP. and 2700 max RPM.

Another thing to consider, the STC limits the engine to 2500 continuous max rpm. 

 

[Cruiser]

3 hours ago, teejayevans said:

Ovation has a service ceiling of 20000?

No, that is as high as the charts go, the service ceiling is a little higher than that.

[LANCECASPER]

6 hours ago, teejayevans said:

Ovation has a service ceiling of 20000?

Yes the service ceiling is 20,000      http://www.pilotfriend.com/aircraft performance/Mooney/57.htm

                      http://www.airmart.com/sites/default/files/Mooney M20R OVATION Performance Specs.pdf

 

The absolute ceiling is higher.          https://en.wikipedia.org/wiki/Ceiling_(aeronautics)

[GeorgePerry]

4 hours ago, Cruiser said:

Look at it this way. The IO550 engine is the same. The STC just adds 30 HP and 200 RPM to the Top End.

When you operate the engine anywhere below the added power and rpm the performance should be the same from the engine's point of view. 

You also changed the prop from two blades to three blades. Besides looking really cool, you will actually loose a little speed in cruise but get a huge boost in take off and climb performance. 

As for the charts, 24 x 2400 or any other combination is going to be identical except for the effect of the propeller change. Remember though the O2 and O3 charts are based on 280 HP. and 2500 max RPM. not 310 HP. and 2700 max RPM.

Another thing to consider, the STC limits the engine to 2500 continuous max rpm. 

 

I think you might be wrong about the RPM limitation.  Here's a copy of the midwest mooney version of the STC paperwork.   Shows max continuous RPM as 2700 with recommended max of 2550

Also Hartzell says the three blade replacement is as good or better in cruise than the 2 blade McCauley.  But admittedly they might be somewhat bias.

[Cruiser]

I will have to look in my AFMS.

The STC is stated slightly different. See section 4 specifications. (original issue July 2003)

[GeorgePerry]

Could be several versions of the STC floating around.  It has evolved over the years.   I am getting my 310 STC through Mooney so as soon as I pick up the plane and I have the "actual paperwork" I'll scan and post.

[StevenL757]

George, although Mooney now owns the STC, a call to Bob Minnis (who actually developed and flight-tested the numbers that fed into that chart) might help provide more clarity.  Let me know if you need his contact details.

[GeorgePerry]

Please send them to me in a PM!  much appreciated!

[carusoam]

+1 for the call to Mr. Minnis!

He his outgoing and detailed about his work. He generously adjusted his verbal delivery to match the speed of my pen.  The facts were just flowing faster than I could keep up.

He speaks the details of what the IO550 was originally designed to do.  310hp is not really close to the max design number.

It would be really fun to run this engine in an experimental airframe!

Best regards,

-a-

[StevenL757]

Correct.  The IO550N I have onboard was actually tested perform and sustain a max power setting in excess of 335bhp.  So you're correct...the 310 number is conservative, even for that big of an engine.  The Ovations and Eagles carrying them are, in fact, overpowered according to Bob.  A beautiful thing.

In George's language, it's kinda' like putting a pair of F414 engines into an A/B/C/D Hornet instead of the Super Hornet.  :-)

[StevenL757]

2 hours ago, GeorgePerry said:

Please send them to me in a PM!  much appreciated!

Absolutely...sent just now.