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Do you reduce throttle and/or prop in climb of NA Mooney?  

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  1. 1. Do you reduce throttle and/or prop in climb of NA Mooney?

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Posted

The POH gives you the option of "Normal" or "Best Rate of Climb." Normal involves reducing power to 2600/26" in the climb whereas Best Rate you just leave everything full till you reach cruise altitude. I've had instructors tell me to bring it back but I've read some compelling arguments for keeping it in all the way (you'll end up below 26" in 4 minutes anyway and the extra speed improves cooling).


Sorry if this topic has been covered before. Also do you lean in the climb? Are you maintaining target EGT, keeping it all in, or climbing lean of peak? Seriously does anyone fly the climb LOP??

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Posted

This is an interesting post.


I think I am the only one that has a certain procedure and I don’t have any reason for it other than I think it helps with cooling. I give the plane full power until I am at 1k ft. at that point I pull back the power to 2600rpm and 25mp. In my climb when I get below 25mp I increase it as much as I can till I get the max while maintaining 2600rpm which I use for cruise. I also start to lean the engine at 1kft. Again I think I am the only one that does this.

Posted

i was taught to reduce power and rpm to 26/26 at 1000' agl and stay full rich in climb. but, in the 16 years that i've flown our mooney i've evolved to throttle and prop full forward and i start leaning(rich of peak) at about 3000'. the only exception is in the summer months when i occasionally reduce rpm to keep oil temperature down in long climbs to cool air.

Posted

Makes a difference if you are NA or turbo.  In my 231 you need to be at full power to produce the fuel flow (22-24.5 gph) needed to cool the engine.  I know some people with intercooled 231's who believe they are doing a cruise climb of some kind.  But when I inquire, they are using an MP like 34" that, during the course of the climb, becomes the setting for 100% HP pretty quickly. 

Posted

All knobs forward


pitch for 105kts


ram air open at 500ft if the air is clean


adjust mixture to maintain 1250-1300df on leanest CHT (which is ~250-300 ROP @<4000ft).


cruise@2500rpm, mixture based on alt.


The only time I reduce throttle after take-off roll is in descent or in turbulence.

Posted

and another thing.......


i recently had a flight review with a new instructor(it's always good to get a new perspective on how you're doing things) and i told her that i knew she wouldn't like the way i took off because i like to keep the flight angle shallow and airspeed high as opposed to climbing at vx. although many years ago i was taught to climb to a safe altitude as quickly as possible, i prefer to be able to see where i'm going, and in the event of a power loss the yoke push would not be as radical....which to me feels safer. to my surprise she agreed with me.


any thoughts? has the theory changed?

Posted

Quote: rorythedog

and another thing.......

i recently had a flight review with a new instructor(it's always good to get a new perspective on how you're doing things) and i told her that i knew she wouldn't like the way i took off because i like to keep the flight angle shallow and airspeed high as opposed to climbing at vx. although many years ago i was taught to climb to a safe altitude as quickly as possible, i prefer to be able to see where i'm going, and in the event of a power loss the yoke push would not be as radical....which to me feels safer. to my surprise she agreed with me.

any thoughts? has the theory changed?

Posted

I start with a Vx climb until I'm clear of the trees, then relax to Vy in the wintertime, a little slower in the summer due to temperature needles moving too far to the right. This is managed with the yoke--throttle and prop stay forward as far as I can push 'em. Vy = 100 mph - altitude in thousands up to 10,000 msl at 90 mph.


Cruise climb is another matter, but even then it's usually everything forward and maintain a higher airspeed [~120 mph].

Posted

Quote: tomcullen

I think climbing at 100ROP as Bob suggests is a bad idea.  The CHT data he puts in his evaluation reports only reinforces that it's a bad idea, but then he's usually flying someone else's airplane...

Posted

When I was flying behind a NA IO360, I'd rotate, retract (who cares about the airplane if the engine dies now), establish Vx, retract flaps, climb at Vx to 1000 feet full power, continue climbing at Vy to my altitude, pull in mixture as required to keep CHT up/down. This was in an Arrow with Vortex Generators so my true Vx was somewhere around 75mph and I'd be at 1000 by the end of my 5500 runway here at KCBF essentially guaranteeing a safe return to the runway, always. I do not see the point of reducing RPM and/or MP in a NA engine, density altitude will do that for you pretty quickly and altitude means options.


With my Bravo, things got a bit more complicated but here is what I found works for me VFR:


Rotate at 66knots, retract, here is my 85knots, retract flaps, keep it at Vx to 1000 feet, lower the nose, accelerate to 120knots, reduce to 34/2400,  close cowl flaps if OAT is low, keep them 1/2 open if not, still full mixture, keep on going until cruise altitude, every now and then hit the down button on my KFC 150 to keep my 120knots, usually ending at about 500fpm at 17,000-18,000.


When in the mountains, I'll keep it at Vx and full power as long I feel is needed.


IFR departure, if ceiling more than 1000 feet, same as above.


If going into soup right away, I take off at 34/2400 close to 75knots, retract the gear ASAP, flaps at 85knots and I just climb out at 120knots. Less work, more time to look for autopilot screw ups. I don't fly IFR in the mountains.


 

Posted


Mike,


 


I have always “since I’ve owned the Mooney” climbed at WOT and 2700RPM.  For “Normal” climb in the POH it says to use 26” MP and going back through my engine monitor data, the MP on the takeoff roll is generally around 28” and within 2:30 it is down to 26”.  Other climb specs in the POH for best rate or angle it just states full power.  It doesn’t seem that these days there is any valid argument for reducing power after takeoff?


 


This was taken from Lycomings Key Reprints book:


Most normally aspirated engines are rated at full power for takeoff and climb indefinitely, provided engine temperatures and pressures are within the green arc area of the engine instruments.


This was taken from “Pelicans Perch #64” from the infamous Mr. Deakin:


Climb power? Use the same power you used for takeoff (unless there is an explicit limitation). If you pulled the RPM back for less noise, you can leave it there, or run it back up to full redline RPM once noise is no longer a concern. The choice is yours. Or pick a smooth RPM in between, if there is one. Simplify your life, and just leave the throttle wide open.


Posted

Quote: Bnicolette

 

Mike,

 

I have always “since I’ve owned the Mooney” climbed at WOT and 2700RPM.  For “Normal” climb in the POH it says to use 26” MP and going back through my engine monitor data, the MP on the takeoff roll is generally around 28” and within 2:30 it is down to 26”.  Other climb specs in the POH for best rate or angle it just states full power.  It doesn’t seem that these days there is any valid argument for reducing power after takeoff?

 

Posted

Becca: To be perfectly honest i do it because the POH says so.


As for the full rich, yes its just for cooling.


I have never had a fouled plug, and yes my POH was written 50 years ago also.

Posted

Brett: It was me that posted that and you could be quite correct, it may have indeed been changed many years ago.


 As i mentioned my POH was written over 50 years ago. ( I have a 1959 M20A)


 

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