real world performance differences between Acclaim and Ovation

[carusoam]

Keep in mind…

The NA Normally aspirated IO550 has decreasing power as the air gets thinner…

So our MP is decreasing noticeably with each 1k’ of altitude… which occurs about 1” per 1k’…

 

Our wind resistance is also decreasing with each 1k’…. Which is nice….

Our best performance matches the decrease in power with the decrease in drag….  The two lines cross on an altitude based graph…

Sooooo…. We see our best performance around 8k’ or so….

 

I usually select a cruise altitude above 10k’ for best glide range….   

And take the power that is available….

Run WOT, with all cylinders just past peak…. And the TopProp at 2550…. For a great combination of speed and efficiency…

 

I would gladly select an Acclaim over the O, IF my usual trip was longer than 200nm…

Thin air of the FLs has a magical way of reducing drag….

A pair of TNs with their matching intercoolers magically keeps power at a high level….

TN’d pilots get to watch their TITs for best maintenance intervals….

Flying an NA engine is as simple as it gets….

 

The 310hp Ovation can climb to and cruise in the lower FLs…  but, that is where having a good O2 system becomes important…. More complexity to keep track of.

 

Go LB!

Best regards,

-a-

[GaryP1007]

Keep in mind…
The NA Normally aspirated IO550 has decreasing power as the air gets thinner…
So our MP is decreasing noticeably with each 1k’ of altitude… which occurs about 1” per 1k’…
 
Our wind resistance is also decreasing with each 1k’…. Which is nice….
Our best performance matches the decrease in power with the decrease in drag….  The two lines cross on an altitude based graph…
Sooooo…. We see our best performance around 8k’ or so….
 
I usually select a cruise altitude above 10k’ for best glide range….   
And take the power that is available….
Run WOT, with all cylinders just past peak…. And the TopProp at 2550…. For a great combination of speed and efficiency…
 
I would gladly select an Acclaim over the O, IF my usual trip was longer than 200nm…
Thin air of the FLs has a magical way of reducing drag….
A pair of TNs with their matching intercoolers magically keeps power at a high level….
TN’d pilots get to watch their TITs for best maintenance intervals….
Flying an NA engine is as simple as it gets….
 
The 310hp Ovation can climb to and cruise in the lower FLs…  but, that is where having a good O2 system becomes important…. More complexity to keep track of.
 
Go LB!
Best regards,
-a-

Great insight! Thank you. I had been flying WOT and about 2400-2450, let me try higher next time. I am almost always about 10k here and often 12-14.

Love learning this.


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[carusoam]

2 minutes ago, GaryP1007 said:

Great insight! Thank you. I had been flying WOT and about 2400-2450, let me try higher next time. I am almost always about 10k here and often 12-14.

Love learning this.


Sent from my iPhone using Tapatalk

I’m always a good source… of other people’s information…!

Some of the best information available for flying the O…. Gets written by @StevenL757 he comes with a ton of credibility….   

 

Best regards,

-a-

[AeroEng]

With this great conversation, I thought I’d throw my cruise configuration into the data pool.  ‘07 Acclaim. 
 

TAS at 205 at 17.5k, 30”, 2400 and 15.7 gph. 

[rickseeman]

The strange thing to me is how an Ovation (according to the POH) can do 178 knots at 20,000 ft. Shocking to me. Not to mention I think the fuel flow is sub 10GPH.

[Niko182]

Just now, rickseeman said:

The strange thing to me is how an Ovation (according to the POH) can do 178 knots at 20,000 ft. Shocking to me. Not to mention I think the fuel flow is sub 10GPH.

Thats sounds about accurate. At 14500 feet i usually still see 180 knots and thats at 2450rpm and peak or barely LOP. not using the full 2700rpm.

[carusoam]

Normally aspirated engines are running low on MP by the time they get to the FLs…

Soooo… flying in the FLs often with an O, would be sub optimal….   

 

The cool thing with an O3 powered O…. The initial climb rates are fantastic… and running 2700rpm is possible…

Best regards,

-a-

[Pinecone]

On 2/23/2020 at 10:30 PM, gsxrpilot said:

All the Mooneys are fast and efficient. And if you're willing to burn more gas, you can go faster. But if you're willing to strap on the O2 mask, I still don't think anything can beat the pure efficiency of the 252. And remember, the best speed mod is skipping a fuel stop. 

Based on these posts, I am still loving my 252/Encore.

174 KTAS in the mid teens on 10.3 GPH

[GeeBee]

The original owner of my Ovation set an NAA speed record, KLAS-KPIT. FL 230.  She set another KPIT to PANC. Me? I hate O2 masks. I'm too old for that stuff. I fly an Ovation because of that and I don't fly out West very much. Sometimes though, I feel not worthy of the airplane compared to her!

 

[Niko182]

2 hours ago, GeeBee said:

The original owner of my Ovation set an NAA speed record, KLAS-KPIT. FL 230.  She set another KPIT to PANC. Me? I hate O2 masks. I'm too old for that stuff. I fly an Ovation because of that and I don't fly out West very much. Sometimes though, I feel not worthy of the airplane compared to her!

 

Do you know what the record was, or do you have an archived flightaware link?

[GeeBee]

2 hours ago, Niko182 said:

Do you know what the record was, or do you have an archived flightaware link?

I do not. If you are an NAA member you can look it up. NAA.aero

 

[jlunseth]

Well, to me the gain in airspeed with altitude is largely academic because whether you should be going higher to gain TAS is a function of which direction you are going and what the winds aloft are. The winds aloft have a magic way of losing at least as much and usually more GS than the gain in TAS if you are flying westerly, especially in the cold weather months. It’s like sailing, you take what the wind gives you. Cruising at 175 TAS is not so nifty if the headwind is 50 = 125 GS, and you could have made 132 if you had just not done the climb and stayed lower. That said, the joy rides with that 50 (or more) at your back are really nice.