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McCauley 3Blatt Prop for 1977M20C


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1 hour ago, jwarren2 said:

I was always lead to believe the three blade is sexier on the ramp and gives better climb performance but the two blades is a "few" knots faster in cruise.

CG is a little further forward, but I've never had problems because of it. It was dynamically balanced at install, and I checked it 12 years later, still at 0.01 ips.

I cruise at 7500-10,000 msl at 145-148 KTAS, lots of photos posted here already. 

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The official WnB was done on a piece of paper and placed in the logs... it often got lost as it looked unofficial...

As far as knowing the stations for pilots, back seat, baggage and hat rack, and fuel...

That is the classic FAA M20 document that defines all the various Mooneys ever built...

Search on weight and balance M20B,C,D,E... all the short bodies will have the same stations...

The front seats are allowed to move on the rails... everything else is fixed....

Expect that everything will be in inches and pounds for the original format...
 

wait for somebody else to share better detail...

A lot is easy to share since many of us are using fore flight or WnB... and classic excel...

Best regards,

-a-

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All distances (arms) are in the Type Certificate, including each position that the front seats can lock into.

You should have a document listing the empty weight and CG of your particular airplane. Then add passenget weights, baggage and recalculate CG.

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A 3 blade McCauley was installed prior to my purchase.  I have no complaints.  It is heavier and the RPM limitations are different.   According to my logs a Hartzell HC-C2YK-1 2-blade was removed (weight 57 lbs arm -30.16 inches).  A McCauley prop B3D36C424/74SA weighing 71.3 (same arm) was installed.

Tach marking changed: Green Arc - Normal 2200 to 2700 RPM, Yellow Arc - Caution 1650 to 2200 RPM

Placard installed: "Avoid continuous operation below 15" M.P. setting between 1650 and 2200 RPM when above 85 KIAS (100 MPH).

PO also installed a lightweight starter and alternator so the weight gain was offset. 

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Previous owner installed 3 blade for Ground Clearance (makes a difference) and climb performance.  However the added weight did shift the CG forward to the point that I carry 70 LBS of ballast to keep it in the envelope. Battery is still forward.

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2 hours ago, luv737s said:

Previous owner installed 3 blade for Ground Clearance (makes a difference) and climb performance.  However the added weight did shift the CG forward to the point that I carry 70 LBS of ballast to keep it in the envelope. Battery is still forward.

Blade length, and therefore ground clearance, is the same for 2-blade and 3-blade props on our Mooneys. 

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Rumor has it, it also crushes your glide ratio in an engine out. 

This adds up to 200fpm decent. Cruising at 8k AGL and Vg of, it can make you lose 2.5 Minutes of air time or 4 SM miles of Distance at 104mph.  

Edited by MICKEY
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6 minutes ago, MICKEY said:

Rumor has it, it also crushes your glide ratio in an engine out. 

This adds up to 200fpm decent. Cruising at 8k AGL and Vg of, it can make you lose 2.5 Minutes of air time or 4 SM miles of Distance at 104mph.  

Pull the prop ba k to coarse pitch / low RPM will make a huge difference. I've never had a problem with glide distance with mine. And I generally ignore rumors. 

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3 minutes ago, Hank said:

Pull the prop ba k to coarse pitch / low RPM will make a huge difference. I've never had a problem with glide distance with mine. And I generally ignore rumors. 

I agree.  I don't think it is  "Rumor", more... statistically speaking it would increased drag, due to more surface area. 

Just Food for thought.  I don't think Id change the number prop blades based on single engine out performance.  

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I replaced my two blade several years ago for a three blade. 

I noticed no real airspeed decrease.

Climb is much much better on hot days,. ( main reason for upgrade )

I experienced no vibration problems. Make sure to have balanced once installed. 

My glide is not reduced. 

A tad more nose heavy but a light weight starter, alternator really helps. 
 

 

 


 


 


 

 
 

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