Ovation Power Settings for Different Flight Segments

[Jeff_S]

As I work to get more intuitive on flying the O3, I'd appreciate others' feedback on the power settings for different regimes of flight. I did a search and there's plenty of threads on climb and cruise. I'm more interested in the power settings people use for approaches, both instrument approaches and regular VFR landing patterns. I didn't find any discussions on those.

 

Thanks in advance for your advice!

 

Jeff

[PMcClure]

Jeff, Congrats on your new plane!

 

I use 17" dirty and 15" clean for level flight on approach or in the pattern. This keeps me below gear speed. In decent, I use 13" dirty which gives me 90 knots or so. 12.5-13" on final gives me 85 knots on most days.

 

For VFR flights, I usually see 17" on 45, 15" in downwind, gear down (usually before the numbers to help slow down), 13" then flaps, then 500 fpm down with 2nd notch of flaps on base, adjusting to 13" and 90 knots, then turn to final with another adjustment to keep her at 85 knots. If done perfectly, keeping 13" will set you up nice. 

 

For approach, I use 17" up until the decent, then adjust to 15", then 13" (dirty) at the final fix, giving me 90 knots and 500 fpm for normal approaches. 

 

This all works pretty well for me. The trick is to stay ahead of the airplane. The first time I flew an approach in IFR, I was approaching the IF at 250knots groundspeed, something I never had to think about before!

 

PS - My ovation is limited to 2500rpm. But I think this should translate close for your 2700 rpm bird. 

 

One bit of caution, practice your go around before you need to. Full throttle after dumping the full flaps gives you a serious pitch up condition. Shocking is about the right word for it and all your force may not be enough to hold the nose down. Throttle, TRIM TRIM TRIM, Flaps (in increments). 

[BorealOne]

The above is pretty close to what I do on my 310hp Ovation.

 

Cruise is WOT, 2400 RPM.

 

On descent, I'll do 20" with speed brakes deployed until the IAF, then bring her down to 15" clean. I'll deploy gear and reduce to 13" and 2300 rpm by the FAF - with a notch of flaps that gives me 90 and 500 fpm. 

[Jeff_S]

Thanks Guys. I'm having fun getting to know the new bird...its especially interesting how much difference in energy there is with the extra weight and power compared to my J. While the target airspeed numbers are pretty much the same, getting to those numbers is the learning experience. I'll use these data points when I fly some practice approaches this weekend. Even just getting around on the ground takes some getting used-to.  I find I have to be more active on/off the throttle while taxiing to get started moving but then to keep it down to manageable speeds.

 

Lots to learn again, but that's the fun part.

[carusoam]

Increased mass...

The first hint is pushing and pulling around the hangar takes a significant amount of energy...

Working on my tug project again today....

Measured step height for ramps....

Placed order for diode....

Best regards,

-a-

[Txbyker]

Jeff, I did my transition training with Premier's head instructor.  Not to insult anyone but one thing he told me if you bounce just go around.  The third bounce is the usually the one that gets us into trouble.  I did my share of go around early on.

 

15" on downwind, full prop and mix

14" on base clean, slows to 90 kts

13" on final IAF with flaps and gear should drop to <90 kts and 500 ft min

 

Over the numbers at 80 and flare at 70 and just keep trimming up.  Twist the throttle all the way out else any throttle and you will float.

 

I did some training with a MAPA proficiency instructor and he had me coming in much faster at 90 but you will float a ways but you will have more positive control.

 

Russ

[BorealOne]

Let me echo the 'go around'. I did an approach last week into a 3000' strip. 1000' and 1/2 mile visibility in FU. Community radio operator reported winds calm, so I set up for the one and only RNAV. However, by the time I had field visual, a 10 kt tailwind had come off the lake. I did my best, but determined at the 1/2 way down the runway that there was no way I could bleed enough speed to land in the distance remaining, and went around. Nice to know what to expect - heavy heavy controls and lots of trim.

 

All O pilots should practice and remain proficient on go arounds.

[BorealOne]

Jeff - one more little bit of advice.

 

Read and commit to memory Mike Busch's advice on operating the big-bore TCM during various phases of flight.

 

http://www.avweb.com/news/airman/184350-1.html?redirected=1

[Greg_D]

Use the attached images for a good place to start...

Normal ILS.bmp

NonPrec.bmp

[Jeff_S]

Jeff - one more little bit of advice.

 

Read and commit to memory Mike Busch's advice on operating the big-bore TCM during various phases of flight.

 

http://www.avweb.com/news/airman/184350-1.html?redirected=1

 

Thanks! I did find that already when Googling "IO 550 Hot Starts" so I've been going over it. Seems like it was written before he found the gospel on LOP operations in cruise, but otherwise a solid piece of work. I used his hot start technique just the other day for my first-ever attempt at it.  Aside from learning that you do have to crack the throttle a bit and not leave it all the way out, the engine started up just fine. Weird as it sounds, with everything I've heard about the difficulty hot-starting these engines, that has been one of my biggest anxieties. But now I know the technique...knock on wood!

[carusoam]

The big difference with the IO550....

There is a fuel return line going back to the tank(selector switch)...

This allows cool fuel to replace warmed bubbling fuel that is typical of the hot start of the IO360s.

Keep this in mind while following the procedure.

Best regards,

-a-

[PMcClure]

Hope you are enjoying your plane Jeff. 

 

On hot starts, I have three sure fire methods to start large bore continentals. 

 

1st is to start normally. As you crank, advance the throttle until the right air fuel mixture is reached and it fires up. This works for me every time, and I used it on the Ovation and my Bonanza. But sometimes it causes high rpms on the ramp and can unnerve pax and line men. 

 

2nd method is:

1.      Throttle – Full Open

2.      Mixture – Idle Cut Off

3.      Boost Pump - High for 5 seconds or Low for 15 seconds

4.      Throttle – Idle (then two half-turns in for the proper idle RPM of 800 – 1000)

5.      Mixture – Full Forward

6.      Starter Switch – Turn and Push

 

Been doing this for last few months and works every time. Sometimes need to bump fuel pump after start if it starts to die again. smooth starts and 1000 rpm. 

 

3rd is to flood it. But I don't like this method for several reasons. 

[tascher]

All the numbers and go around advice posted in reply look good - the pitch up going to full throttle with full flaps gets your full attention. I'm sure we've all developed our own variations on the numbers. The only things that I would throw in - to use or toss as you see fit - are as follows:

Bob Minnis, who is behind the 310hp STC and I'd believe was lead on the IO550G project at Continental, will tell you to keep 2700 all the way uphill - at least he has said that in the past. I can't quite bring myself to do that and reduce from 2700 to 2600 anywhere from 1000' to 2000' into the climb and keep 2600 for the balance of the climb through level out. I've taken to 2550, WOT, ROP, in cruise (roughly 7000' and above - lower altitudes result in MPs above 78% on the Midwest STC power chart) and pull it back to 2400 (or lower) for the decent.

I very slowly dial back throttle and dial in mixture as needed to keep MP and EGT below whatever I happen to have for target numbers at first level off i.e. between 22" and 23" and no greater than whatever cruise EGT I come up with after level off and acceleration - say 1500 from the reading at the junction where the exhaust stacks come together (significantly cooler at each individual cylinder). I repeat the process with the appropriate lower MP target going into the IAP or the pattern. (I learned the hard way with a few hair on fire pattern entries in my early hours in the plane and a bit again after the conversion from 280 to 310). I do subscribe to the leave the mixture lean for landing school. When the power reduction starts dropping the EGT I leave the mixture alone (up to the moment that I have to go around. Yes, I was slow on that once or twice, but I usually taxi in lean.) I do advance the prop on final once the power reduction takes it below the set RPM - I figure its worth a little more aerodynamic braking. Lastly, I've learned to slow it down on short final. Unless gusty or landing on an infinitely long runway, especially if flying alone and/or with a light fuel load, a short final number closer to 70 than 80 makes life a lot easier. My 2 (or fewer) cents...

[carusoam]

A conversation with Mr. Minnis is one of those memorable ones...

The IO550 was built for much higher HP than we currently use at altitude...

Take notes, there is a lot of details....

Best regards,

-a-

[jhbehrens]

In my 310hp Eagle, which is identical to the O3 engine wise, I have one other technique for hot starting for which you get only one chance. Before switching off, set throttle to 1000 RPM before mixture to cutoff. The when you want to start up again, dont touch anything (except the mixture of course), just start and keep a hand on the boost pump. When the engine catches use a few seconds of boost to keep it going. If you don't manage to keep it going revert to other techniques.

[Jeff_S]

My confidence (hubris?) about hot starts reared up on me this afternoon. On landing I was coming in a bit fast so I had pulled the throttle all the way out to glide in. Perhaps the mixture was too lean, as on rollout the engine quit. Luckily I could roll onto the taxiway, but it took me a few minutes to get it started. Eventually had to use a flooded technique. I went up to the fuel depot and gassed her up, and then had trouble starting again with all the standard techniques, except finally using a flooded start I got it going. But on taxing back down a hill I throttled back and she quit AGAIN!  This was right in front of Epps Aviation and a guy came up in a truck and asked if I needed help. I said "I'll let you know."  Once more, I could get it to fire a bit and then it would die. Finally I did a flooded technique and got it started to fire, and as it seemed like it was quitting again I gave it a shot of prime and that did the trick.

 

Before shutting down I did a run-up to test all the cylinders and they looked fine on the engine gauge, and after I got it normalized then it ran okay even at idle. My theory is that I was running so lean I got it into some type of vapor lock that took awhile to clear.  Feel free to educate me if that's way off base.

 

Oy vey!

[PMcClure]

Jeff, 

 

I have had this problem occasionally in the past. Especially after long and lean flights. I put it back to full rich in the pattern now and also keep an eye on the rpms on roll out. But have your mechanic check your low pressure flow.  TCM engines are susceptible to slight variations and need to be adjusted on occasion. 

 

Come on over this weekend if you are out flying and we can compare notes if you want. 

[Txbyker]

I had a similar experience yesterday in that I switched tanks during GUMPS and left the boost pump on. Pulling back to idle would stop the engine.

[Jeff_S]

Thanks Paul.  I may take you up on that, although it looks like we're back in a storm period this weekend.  Heck, with all the weather I've flown through lately that should be no big deal!  I'll talk to my A/P though, and get his thoughts about adjustments.  The fact is I've flown this plane more in the last three weeks than it has flown in a year, since it was undergoing all its repairs. The engine now has about 10 hours on it since the tear-down/rebuild, so I imagine its natural for it to need some tweaking as it breaks into normal operating mode.

[jhbehrens]

2nd method is:

1.      Throttle – Full Open

2.      Mixture – Idle Cut Off

3.      Boost Pump - High for 5 seconds or Low for 15 seconds

4.      Throttle – Idle (then two half-turns in for the proper idle RPM of 800 – 1000)

5.      Mixture – Full Forward

6.      Starter Switch – Turn and Push

 

Been doing this for last few months and works every time. Sometimes need to bump fuel pump after start if it starts to die again. smooth starts and 1000 rpm. 

 

I tried this and it flooded the engine (fuel coming out near the front tire) and it didn't start. IO-550G

[jhbehrens]

My confidence (hubris?) about hot starts reared up on me this afternoon. On landing I was coming in a bit fast so I had pulled the throttle all the way out to glide in. Perhaps the mixture was too lean, as on rollout the engine quit. Luckily I could roll onto the taxiway, but it took me a few minutes to get it started. Eventually had to use a flooded technique. I went up to the fuel depot and gassed her up, and then had trouble starting again with all the standard techniques, except finally using a flooded start I got it going. But on taxing back down a hill I throttled back and she quit AGAIN!  This was right in front of Epps Aviation and a guy came up in a truck and asked if I needed help. I said "I'll let you know."  Once more, I could get it to fire a bit and then it would die. Finally I did a flooded technique and got it started to fire, and as it seemed like it was quitting again I gave it a shot of prime and that did the trick.

 

Before shutting down I did a run-up to test all the cylinders and they looked fine on the engine gauge, and after I got it normalized then it ran okay even at idle. My theory is that I was running so lean I got it into some type of vapor lock that took awhile to clear.  Feel free to educate me if that's way off base.

 

Oy vey!

 

This has also happened to me after long flights when I forgot/chose not to put the mixture back at full richt just before landing. I now also take RPM back to 1000 during roll-out once the speed has bled off.

When it happens, if you quickly push mixture full rich and add some throttle it will usually not shut off.

[carusoam]

Something I learned over a two year period...

Mixture in idle cut-off should be directing fuel back to the selector valve and selected tank...

It should not be sending the fuel to the engine or on the ground....

What I do know now...

Fuel pump seals can leak (age related) intentionally pouring fuel on the ground...

What looks like a flooded start may actually still be starved for fuel...

Leading to a confusing starting situation...

Things to check...

- mixture pulled all the way back.

- pump on

- check to see if fuel is venting to the ground

I found this out by a neighbor observing fuel draining out of my plane while I was priming it...

Later on, I saw a drip fall from the pump's vent while I was in the hanger...

There is not many ways to know this is happening on your own.

Or maybe it was just me,

-a-

[Seth]

My confidence (hubris?) about hot starts reared up on me this afternoon. On landing I was coming in a bit fast so I had pulled the throttle all the way out to glide in. Perhaps the mixture was too lean, as on rollout the engine quit. Luckily I could roll onto the taxiway, but it took me a few minutes to get it started. Eventually had to use a flooded technique. I went up to the fuel depot and gassed her up, and then had trouble starting again with all the standard techniques, except finally using a flooded start I got it going. But on taxing back down a hill I throttled back and she quit AGAIN!  This was right in front of Epps Aviation and a guy came up in a truck and asked if I needed help. I said "I'll let you know."  Once more, I could get it to fire a bit and then it would die. Finally I did a flooded technique and got it started to fire, and as it seemed like it was quitting again I gave it a shot of prime and that did the trick.

 

Before shutting down I did a run-up to test all the cylinders and they looked fine on the engine gauge, and after I got it normalized then it ran okay even at idle. My theory is that I was running so lean I got it into some type of vapor lock that took awhile to clear.  Feel free to educate me if that's way off base.

 

Oy vey!

Had this happen to me in my Missile on rollout soon after the engine overhaul.  It was not a good feeling to have the engine die on me on rollout.  I got off the runway, and had to get the engine started again, which also took a few tries.  It was not a LOP flight but a longer ROP cross country.  The fuel flow at idle was evidently too rich.  I adjusted my technique to on final lean the engine a bit, and then when I pull power for landing, it wouldn't quit on me.  The problem is you have to remember to put the mixture in full if you do a go around.

 

Once adjusted properly on the idle mixture, the top end mixture and full rich was too low (this was rectified a few flight hours later).  On the missile at least, you adjust the idle mixture and rich mixture settings separately, but they do affect each other.  Not sure about the O, but it's the IO-550.  Do get your idle mixture settings checked.

 

 

 

Also, from the linked article:

 

"Every POH I've ever read instructs you to advance the mixture to full-rich on final prior to landing. Don't do it! Pouring cold fuel on a hot cylinder head simply can't be a good thing for cylinder longevity. I recommend leaving the mixture leaned out for landing and taxi. I also recommend setting the props to top-of-the-green RPM, not shoving them full forward the way the POH instructs. Of course, if you have to make a go-around or a missed approach, don't forget to advance the mixture and prop controls before throttling up to full power."

 

 

 

 

 

 

-Seth

[Jeff_S]

Thanks Seth. Yes, my A/P did some analysis and he felt the idle mixture was set too rich as well.  It's possible I suppose, since it was set in Florida (sea level) during the springtime (cooler months) compared to now being in Atlanta at 1000' elevation in the hot summer. He leaned out the idle mixture and I did notice a difference.  I'm more comfortable now knowing what I need to do in these situations so I'm just going to monitor it and tweak as necessary.

 

I did discover that the A/C loads the alternator for an effective 300-400 RPM drop at idle, which when coupled with the too-rich mixture may have increased the problems.