How "slo can you go" "how little can you burn"

[nels]

From an article in MAPA on the M20E test:

"If you fly an E model, you will get the most cruise performance and good economy from your airplane where we tested--full throttle, 2500 RPM, leaned to 50 degrees rich of peak EGT and cowl flaps closed."

"Just like the C, the induction and exhaust systems on the F are designed (tuned) to be most efficient with the throttle in the full open position and at 2500 RPM for continuous cruise. The mixture setting is your choice. You can choose either 1) 100 degrees rich of peak EGT for best power (good speeds, but watch that fuel flow), 2) 50 degrees rich of peak EGT (my recommendation as a perfect compromise between best power and best economy), 3) peak EGT (best economy, but expect a 4 or 5 knot speed loss), or 4) 50 degrees lean of peak EGT with a set of balanced fuel injectors from GAMI".

Was this cruise speed not accomplished at 100% power?? Throttle is at the firewall and yet burn rate was in or around 10gph. If not 100% then how is 100%, 75% or 50% defined?

I am hoping there is no such thing as a dumb question on this forum. Remember, my experience is with a Cessna 150 and that was a long time ago.

 

[jetdriven]

ANY altitude above sea level is going to be less than 100% power.  Throttle full open is not like a car, think of it as an air valve. Air loses density with altitude.  You can use MP and RPM to set power ROP, or FF  to set power LOP.

[nels]

I guess we are deviating from my original question but I'm learning something so I don't mind.

If I am understanding this correctly, it sounds like typically referred to power setting of 65% or 75% etc are actually full throttle settings but at altitudes where max efficiency is less due to the lack of the oxygen component of combustion. So at altitude it is normal to cruise at full throttle? Further manipulation of fuel air ratio at cruise can yield more economy?

Am I close?

[Shadrach]

Quote: nels

I guess we are deviating from my original question but I'm learning something so I don't mind.

If I am understanding this correctly, it sounds like typically referred to power setting of 65% or 75% etc are actually full throttle settings but at altitudes where max efficiency is less due to the lack of the oxygen component of combustion. So at altitude it is normal to cruise at full throttle? Further manipulation of fuel air ratio at cruise can yield more economy?

Am I close?

[Steve65E-NC]

Getting back to the original post.  Nels, unless you want to reach out and travel the Mooney is probably not the plane you want.  Since you are concerned about burn rate, money must be a problem.  So why take on the extra, up-front, maintance and insurance expense of a complex aircraft.  Further, in my opinion, a Mooney is a little more to handle than a 150 or Cherokee.  If I am stale, I don't notice it in those aircraft, I do notice it in the Mooney.  Further, I infer something of an age issue,  I am 68 and plan to monitor my performance carefully as I pass the 70 mark.  If I don't feel that I measure up, I will go back to something like a Cherokee.  Which is too bad as I see the aircraft as primarily  an instrument for travel.

[Steve65E-NC]

Getting back to the original post.  Nels, unless you want to reach out and travel the Mooney is probably not the plane you want.  Since you are concerned about burn rate, money must be a problem.  So why take on the extra, up-front, maintance and insurance expense of a complex aircraft.  Further, in my opinion, a Mooney is a little more to handle than a 150 or Cherokee.  If I am stale, I don't notice it in those aircraft, I do notice it in the Mooney.  Further, I infer something of an age issue,  I am 68 and plan to monitor my performance carefully as I pass the 70 mark.  If I don't feel that I measure up, I will go back to something like a Cherokee.  Which is too bad as I see the aircraft as primarily  an instrument for travel.

[Hank]

Quote: nels

I guess we are deviating from my original question but I'm learning something so I don't mind.

If I am understanding this correctly, it sounds like typically referred to power setting of 65% or 75% etc are actually full throttle settings but at altitudes where max efficiency is less due to the lack of the oxygen component of combustion. So at altitude it is normal to cruise at full throttle? Further manipulation of fuel air ratio at cruise can yield more economy?

Am I close?

[wrench]

1) Get in a club, rent  or partnership for a time in something you were comfortable with like a C172 or Cherokee. Get your skills back up to snuff then consider higher performance.

2) Mooneys will fly comfortably as slow as most C172's and Cherokees with lower fuel burns. I think most will agree.

3) I got back into flying with a Cherokee 180 4 years ago and stepped into my current Mooney 1 1/2 years ago. When just air knocking about 2400or2500/19" is a good comprimise for me but I drop down to 2500/17" for setting up on approaches.

4) When time for cross country trips these aircraft shine, I think most everyone with a N/A "J" flight plan at 155 to 160 kts and flightplan around 11 to 12 GPH. The earlier models aren't much slower in cruise.

5) The option of speed does not have be used but at least you have it if need be, efficiency aside.

6) Two days ago the density altitude was -2150 ft here locally. I'm stating this because I think more than 100% power was available during takeoff and we often refer to 100% power being in standard conditions at sea level so wouldn't I have had more than 100% power available to me until powering back to climb settings. It's like a free nitrous oxide boost!

Save flying all!

[nels]

Thanks for the info, guys. It is extremely helpful. Don't worry about being too basic. I've always thought if I knew the basics the rest I can figure out or at least make sense out of what I am learning.

Steve65 E, I appreciate your concern on the Mooney vs unsophisticated type.  I am concerned about that myself, which is also good. Other pilots I talk to tell me I'll be in the air and checked out in five hours. I figure I want at least twenty hrs of dual time or more if I deam it necessary. I'm 62 and a retired automotive engineer, still in excellent physical and mental shape (I think). Our son lives in Denver and our daughter and son in law are now moving to Denver. A Mooney would be used a lot around the local area for pleasure and time building but often on cross country flights from Cinci to Denver. Being retired I am in no hurry to get anywhere so if the weather looks bad we can just hold out a couple days until it looks good. The expenses are higher on the Mooney vs a Cessna but the early Mooneys are pretty simple so I can't see the maintenance being that far removed from the Cessna/Piper.

[Hank]

Quote: nels

I am in no hurry to get anywhere so if the weather looks bad we can just hold out a couple days until it looks good. The expenses are higher on the Mooney vs a Cessna but the early Mooneys are pretty simple so I can't see the maintenance being that far removed from the Cessna/Piper.

[Steve65E-NC]

Nels, Sounds like the Mooney is the airplane you need.  Beware the landing porpoise.  Hold it off till it quits flying.  For my E, I give a final glance to see than I am below 70 mph.   You can not force a Mooney onto the ground like you can a P or C.  This can be a problem particularly on short fields with steep approach over obstacle.  One nose bounce, apply power and get flying again.  Second bounce you are in an unstable and building oscillation until something breaks.  Ask me how I know.  Spend some training time dedicated to this problem, don't just pass over it.