Power setting while on the clime on Mooney M20J

[Shawn26]

Hello,

 

I’m new to Mooney and I’ve been flying M20J for almost 30+ hrs. There is a connivery that I like to know and I’m sure everyone has there own opinion on this.

 

During clime you’re at full manifold pressure and RPM. Lots of instructors and other pilots saying once you’ve reached 1500AGL the manifold pressure and the RPM should be 25/25 during the clime. Even though they state this method put less stress on the engine, you obviously cutting power to reach your desire altitude and has a impact on your Vertical Clime Rate.

 

POH and many other folks they clime with full High RPM and Manifold pressure till they reach to their desire altitude then they adjust.

 

I would like to know you’re thoughts and which is the safest method so I can adapt. Thank you

 

 

Sent from my iPhone using Tapatalk

[gsxrpilot]

25/25 has been well debunked. There is no need to reduce MP or RPM to 25/25 during the climb. Some like to reduce RPM just for the noise. But I believe most of us here would recommend full MP all the way to your cruising altitude. Obviously you need to lean during the climb as altitude increases and the air gets thiner. But keep the MP full.

[Hank]

Keep everything forward. Why? Next time out, make two climbs (one at reduced power, one with everything forward) and watch your engine temperatures. Climb at least 5000' above your power reduction. Time the climbs, too, and report back with the numbers and which one you think is kinder to your engine. 

[Bob_Belville]

Engine management wisdom has changed in the decades since our POHs were printed. "25 square" and "never over square" were, and in some quarters still are, taught but there is little science behind that thinking for our "modern" engines. Perhaps logical for radials?

You should keep an eye on temps - CHT, EGT, OilT. Airspeed and mixture are the preferred parameters to adjust if necessary. More airspeed and/or more fuel will lower temps if necessary.

As you climb you can lean to keep EGTs fairly constant at least 200F below peak. (You'll only know what peak is from previous experience - no "lean find" while you're climbing at full power!)

While there is a great deal of knowledge here (and a trace of baloney), you should also avail yourself of Pelican Perch  at Avweb (John Deakin) and Mike Busch of Savvy who writes for EAA and AOPA.  

[markejackson02]

The only reason I would reduce power is to reduce temperature.  In South Texas that sometimes happens after a quick turn when the engine is hot to begin with

[jlunseth]

I just had occasion to fly with a local instructor to get instrument current after winter.  I wind up doing this (fly with a local instructor) about once a year. Every single time they nudge me to reduce power to 25 squared.  I fly a turbo, we are never “squared up.” Its just such dogma they have to say it. As I understand it, the formula worked well to give cadet pilots when they were learning to fly radial combat aircraft.  That was a long time ago, but not what we do today.

[Piloto]

The only time I throttle back my 20J is on descent.

José

[jetdriven]

Not even then. About 4 miles  from the airport if vfr. Imc, a little sooner, around the IAF. 

[Bob_Belville]

My E has a lower Vne than your Js which limits full throttle in descent - time to take a pic of Aspen.

[Hank]

2 hours ago, jetdriven said:

Not even then. About 4 miles  from the airport if vfr. Imc, a little sooner, around the IAF. 

That's how I do in my C, too. Leave everything alone, push for 500 fpm descent. I come down around 170mph, just below the yellow. Level off then slow down for pattern entry, drop Takeoff Flaps. Can't get any easier . . . .

[EricJ]

I'm usually in the camp where it's full throttle at take-off and don't touch the throttle again until you need to in descent or approach.    I do usually pull the rpms back a little bit while climbing out after about 700 feet AGL or so, but mostly for noise/comfort.

[midlifeflyer]

I fly a the Js in a large club.  When I get my annual checkout, I need to remember the club 25-squared SOP. Why I would want to reduce available power during a climb (other than for cooling, noise, vibration, but that's mostly prop and not throttle), I have no idea.

Edited May 21, 2018 by midlifeflyer

[carusoam]

Shawn,

There are a couple of old wives tails that get debunked around here often...

...And every now and then a spelling award gets given out...   Clime = Climb.  Clime is short for climate....  

If you like... you can edit the title of your thread, and everything else you have authored...

 

While climbing out FT, Max rpm, keep an eye on CHTs... you might need some work on cooling airflow, or FF, or IAS, to keep CHTs in line...

PP thoughts only, not a CFI or mechanic...

Best regards,

-a-

[Jeff_S]

Isn't anyone here interested in what "connivery" the OP was pointing toward?

That sure looks like an smartphone autocorrect issue to me!  I wonder what the original word was supposed to be.

[carusoam]

10 hours ago, Shawn26 said:

There is a connivery that I like to know and I’m sure everyone has there own opinion on this.

 

Connivery... between two forces that are acting together, ignoring what is in the best interest of the OP...

The two forces....   OWTs and aged POHs...   

The fun part, most people are in agreement on some version of Max Throttle and rpm until different parts of the climb...

 

Setting mixture is probably the next discussion... carbed engines have an extra fuel nozzle to deal with...

Thoughts only,

-a-

[midlifeflyer]

I've always leaned during the climb. Of course, I spent 20 years in Colorado where you leaned for everything!

The most common-sense description of leaning during the climb I've come across is somewhat related to what @Bob_Belville said earlier.

Once you have determined your climb EGT based on a full rich climb at sea level at standard temperature*, that's your target EGT at any altitude. Simply maintain those EGTs during the climb. 

 

(*Yeah, depending on whether you have access to sea level on a standard day, this may have to be a fudge item. And yeah, people will disagree on whether the full rich equivalent is necessary, but the rich mixture also helps with engine cooling)

[Bob_Belville]

4 minutes ago, midlifeflyer said:

I've always leaned during the climb. Of course, I spent 20 years in Colorado where you leaned for everything!

The most common-sense description of leaning during the climb I've come across is somewhat related to what @Bob_Belville said earlier.

Once you have determined your climb EGT based on a full rich climb at sea level at standard temperature*, that's your target EGT at any altitude. Simply maintain those EGTs during the climb. 

 

(*Yeah, depending on whether you have access to sea level on a standard day, this may have to be a fudge item. And yeah, people will disagree on whether the full rich equivalent is necessary, but the rich mixture also helps with engine cooling)

I suppose my "at least 200F below (estimated) peak" is a little more  aggressive than your "match SL full rich (estimated)". Surely either rule of thumb is well out of the red zone and that we're monitoring CHTs. If we're well outside the red zone and if the CHTs are below 380(?) there little need for more fuel. I am also watching FF. In a BTTW climb I want to see at least 11.5 gpm until altitude puts me below ~70% power. YMMV but with a modern EDM we have a lot of great tools.  

[jetdriven]

Yep and above 5-6-7k feet you can lean to “target plus 100” since you are already at and below 75% cruise power settings anyway.  Book says 50 ROP for cruise, which I don’t do, but if it cools at 150 ROP in the climb, then use it. Save the gas. 

Edited May 22, 2018 by jetdriven

[midlifeflyer]

14 hours ago, Bob_Belville said:

I suppose my "at least 200F below (estimated) peak" is a little more  aggressive than your "match SL full rich (estimated)". Surely either rule of thumb is well out of the red zone and that we're monitoring CHTs. If we're well outside the red zone and if the CHTs are below 380(?) there little need for more fuel. I am also watching FF. In a BTTW climb I want to see at least 11.5 gpm until altitude puts me below ~70% power. YMMV but with a modern EDM we have a lot of great tools.  

I've heard mine by some of the "experts" of fuel management (who tend to disagree with each other at some points), but was more born by guestimate leaning for takeoff at high density altitude in Colorado - best power plus a bit more for cooling. But yes,  I also verify with matching target fuel flows and, of course, proper CHTs.

10 hours ago, jetdriven said:

Book says 50 ROP for cruise, which I don’t do

50° ROP is one of "those" POH items which was de rigeur at one time - and is exactly in the Red Zone for most engines. A cynic might say the engine manufacturers knew that all the time.

[Oldguy]

Okay, I know my memory is going, but didn't someone write a paper for their Master's degree on the proposed climb speed Vz and use a 201 for their test plane? I believe it contained several analyses with changing multiple variables to obtain optimum climb rate, engine temperature, and fuel burn to altitude. I have looked for it on the web, but cannot come across it.

Anybody else recall this?

[Bob - S50]

19 minutes ago, Oldguy said:

Okay, I know my memory is going, but didn't someone write a paper for their Master's degree on the proposed climb speed Vz and use a 201 for their test plane? I believe it contained several analyses with changing multiple variables to obtain optimum climb rate, engine temperature, and fuel burn to altitude. I have looked for it on the web, but cannot come across it.

Anybody else recall this?

I do.  Seemed like he climbed at Carson's number.

[jetdriven]

@testwest

besides being a real life test pilot I was present when he used a stock Aerostar 600a with TN engines to whip half the field of SX300s in a real life cross country air race. Quite a show I tell you  

 

Edited May 22, 2018 by jetdriven

[mike_elliott]

2 hours ago, Oldguy said:

Okay, I know my memory is going, but didn't someone write a paper for their Master's degree on the proposed climb speed Vz and use a 201 for their test plane? I believe it contained several analyses with changing multiple variables to obtain optimum climb rate, engine temperature, and fuel burn to altitude. I have looked for it on the web, but cannot come across it.

Anybody else recall this?

Yep, I recall it.

[jetdriven]

https://mooneyspace.com/topic/3270-the-cafe-measure-of-efficiency-mooney-style/

[Hank]

Seems it was his PhD dissertation in Aerospace Engineering. I measured my prop blades 9 ways from Sunday, and made a nice CAD drawing of it.