MT 4-blade Composite Prop for M20 R, S, TN

[John54724]

Allow me the honor of providing this forum advance notice of our latest MT Composite Prop upgrade STC.

 

74" diameter, 4-blade, Scimitar shape, Composite Propeller for all Mooney M20 R, S & TN models.  The STC is approved to include those aircraft with engine performance upgrades.  24v hot prop or fluid de-ice options are available.  The fluid de-ice system is compatable with existing FIKI systems.  Our test ship was a very heavy M20TN with every possible option and we saw improvements in take off, climb and cruise compared to the 3-blade Hartzell that was tested against.  The prop reduced noise inside and out and also reduced the high power operating temps.  The base kit includes the prop with Kevlar spinner and STC for $14,540.  De-ice options, assembly, crate and shipping are extra.  Orders are being taken now for February delivery.

 

Thank you with best regards,

 

John Nielsen, Partner

http://www.Flight-Resource.com

Direct: 715-568-3980

Mooney M20R S TN Datasheet.pdf

[FoxMike]

Just wondering if this is the same prop that was STCed awhile back for the TLS?

[jlunseth]

Very interesting, but can you answer me this?  I see there is a 2 kt. increase in cruise with the Bravo prop.  Is that a 2 kt. increase at the same fuel flow or does the fuel flow change.

 

I may be in the market for one of these in the not too distant future, and the concern I have is that we have been through this in the Mooney community with the conversion of two blade to three blade props in some K's and F's, and climb speed improved but the extra blade is just more drag in cruise and makes the plane slower and less fuel efficient.  So does this prop avoid that, and if so how?

 

I do like the reduction in weight.

[carusoam]

JL,

Watch how the composite prop on an SR22 stops in a very short partial rotation...

I would be looking for a statement regarding the flywheel effect is not required for my engine.

The TopProp on the IO550 adds some speed, but also gets off the ground in a short distance.

Of course, an STC is required to bump up the rpm limit from 2500 to 2700. Increased FF is required for that!

Welcome aboard John,

-a-

[ghovey]

This is grest news Thanks for trying to improve our Mooneys. I look forward to the data

[John54724]

Mike,  We have had STC's for most other Mooney models as a 3-blade and a 4-blade for the M20M but with different blade shape.

 

It is a fact of physics that HP is used/required to rotate mass (engine shops test run using metal clubs that absorb full HP yet make zero thrust).  Reducing mass allows designers to used a more efficient/aggressive profile to absorb energy.  This is what MT does.

 

Regarding 3 vs 4 blade cruise (drag) performance...At altitudes below approx 14K, given exact same plane with a 2, 3 and 4-blade prop, each with exactly the same blade leangth and profile; the 2 blade will be fastest by about 5 kts over the 4-blade.  The 4-blade will have the highest amount of static/low speed thrust resulting in best take off and climb performance.  Generally, as you fly into the teens with thinner air, the drag component is reduced.  Now if you continue to make 300+ HP all the way, you have a massive advantage with flying high using the 4-blade prop.  We have proven this with the Cirrus SR22 with TNIO-550 engines and this same prop.

 

Regarding flywheel effect...the Polar Moment of Inertia of this MT 4-blade prop is exacly the same as the 3-blade, wide chord Hartzell composite prop that is standard equipment on all new Cirrus SR22T aircraft.  This same prop on those aircraft also added performance and reduced operating temps and has been a real hit with over 200 in operation with no problems.  The dynamics of each prop/engine combination are required to be extensively ($$ expensive $$) tested by the FAA as part of the STC approval process.

 

The max RPM for this prop is 2700.  Some models of M20 and some engine mod STC's reduce that.  Our STC Flight Manual Supplement states "no change" to existing engine operations or limitations.  So you continue to operate same as your previous prop.

 

Cruise speeds evaluated were done on the same plane, same day, same weight, same temps with full power and mixture set to full rich, then to best economy flows on a M20TN at 8K and 14K.  The MT was faster by 3-4 Kts TAS in both cases.

 

The price of the MT 4-blade is about half of the cost of the Hartzell 3-blade composite prop used on the Cirrus SR20.

 

Thank you for the great questions...and for welcoming me to your forum.  (This site is very easy to use and one of the best forums I monitor)

 

John

[Seth]

Does this mean with this STC an M20TN can attain 245-246 knots? (3-4 knots over the 242 knot top speed?)

 

-Seth

[John54724]

Seth,  I only have the delta at this moment.  It would be extremely rare (like never happened before in all our STC testing) that the aircraft being tested at max GTOW EVER met or exceeded climb and cruise data in the AFM.  All we look for is "equal or better" vs the best current prop offering in all testing.  With the cost of obtaining an STC, there is a lot of un-official flight tests run before we commit to an application and we would NEVER consider an STC if our prop did not exceed the current best prop on that plane.   It is why we can offer with full confidence, a money back satisfaction guarantee on every one of our prop upgrade STC's.

 

Thank you,  John

[carusoam]

Thanks John.

It's nice to make contact with you.

It would be nice to see the T/O performance of the MT 4-blade prop...

The other guys get the Ovation off the ground in under 900' using 2700rpm limit.

Standard Ovation 1 performance is near 1200', using 2500rpm limit.

600'??? (single pilot and 10 gallons of fuel...)

Best regards,

-a-

[aviatoreb]

Any hope your STC can be extended to cover the TSIO520nb on the M20K rocket?

[Awful_Charlie]

When my existing prop wears out, I'm looking into the 4 blade STC for my Bravo, but one thing concerns me a little is the clearance for getting the lower cowl on and off - it is already quite a juggling act to get the back of the lower cowl over the nose undercarriage assembly and the front end behind the spinner bulkhead, so is this any better or worse with the 4 blade?  Also, what's it like for using the tow bar/power-tow? Does using the available lock from side to side require rotating the prop to avoid contact between the towing apparatus and the prop. blade?

 

Ben

[davidsguerra]

Any hope your STC can be extended to cover the TSIO520nb on the M20K rocket?

this. im sure a lot of rocket owners would upgrade.

[FAST FLIGHT OPTIONS LLC]

How many knots would you say are lost due to the de-ice boots?

[Awful_Charlie]

How many knots would you say are lost due to the de-ice boots?

The POH for a Bravo doesn't list any cruise speed performance degradation for de-ice boots, but does give a 50fpm de-rate for the climb performance

[John54724]

All MT props have a rubber abrasion boot on the inboard leading edge of the blades.  With de-ice this boot is simply replaced with one that has flutes for the fluid to run through.  No change in performance with or without any form of deice on an MT.

John