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bakerocb

Joined: 15 Jan 2006
Posts: 727
Location: FAIRFAX VA

Posted: Sat Feb 26, 2011 2:24 pm Post subject: KIS TR-1 Propeller

2/26/2011



Hello Alfred, You wrote: "........ I'll be using airfields at 6000 ft AMSL 

at temperature of 35 to 40 degrees C."



That helps me understand your desire / need for more takeoff / climb RPM / 

power out of your engine - prop combination than I am faced with.



The Prince propeller selection Wizard is a bit puzzling because it has two 

different propeller recommendations for what appears to be the same airplane 

and engine combination.



A) If you follow the input trail of "KIS TR 1 IO - 240 - 125HP" you wind up 

with a 68 X 69 propeller recommendation. (Which is what I have.)



B) If you follow the input trail of "KISS - IO 240 - 125 HP" you wind up 

with a 62 X 68 propeller recommendation.



See here:



http://www.princeaircraft.com/PriceOrder.aspx



One would think that the 62 X 68 prop would be more of a takeoff / climb 

prop than the 68 X 69 version.

Maybe a conversation with Lonnie Prince is in order to sort out and refine / 

clarify the recommendation.



'OC' Baker Says: "The best investment we can make is the time and effort to 

gather and understand knowledge."



PS: What part of the world will you be operating in with those field / 

density altitudes and temperatures?



==============================================

From: "Alfred Prosser" <aprosser(at)teledynamix.com>

To: <bakerocb(at)cox.net>

Sent: Saturday, February 26, 2011 9:09 AM

Subject: RE: KIS landings

Thanks for the info on your propeller performance OC.



Thing is, I have to rig my plane for operating at density altitudes of 

10,000+ feet because I'll be using airfields at 6000 ft AMSL at temperature 

of 35 to 40 degrees C.



That's a different kettle of fish altogether. Hence the need for every ounce 

of power I can get out of the engine at take-off.



Regards,

                 Alfred

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Mon Feb 28, 2011 5:08 pm Post subject: Re: KIS TR-1 Propeller

Hi OC,



Thanks for the info on your propeller performance.



Using the integrated airframe and propeller performance model which I created some weeks ago now, I have already determined that the best solution for me will be a 67 x 67 prop. Such propeller will also function optimally at 2300 rpm at 7500 feet for cruising. According to Lonnie the P-tip with 67 inch pitch will flex to such an extent under load that it will effectively present a 63 inch pitch during take-off/climb.



By the way, I found it puzzling that the Prince website talks about the propeller diameter being a factor in the flat plate drag of the aircraft. Because the propeller produces netto thrust which increases quadratically with diameter that statement initially failed to compute in my mind. On the other hand however, propeller parasitic losses do increase with diameter and rpm - so perhaps they are implicitly lumping propeller parasitic losses into the overall zero lift drag coefficient for the aircraft (and thereby also into the flat plate area). I have not encountered such point of view before, but it is the only interpretation which makes sense to me. One has to be very careful with that approach though, because the airspeed multiplier by which drag converts into power is of course completely different for the propeller and airframe. 



It remains to obtain torque and thrust curves for a 67 x 67 propeller from Lonnie Prince and his team to confirm that my postulated propeller blade model is not too optimistic in terms of performance - nor too conservative.



Kind regards,

                  Alfred

_________________
_________________________________________

mantafs(at)earthlink.net
Guest

Posted: Wed Mar 02, 2011 6:21 pm Post subject: KIS TR-1 Propeller

Hi Alfred,



One way to think about how the the propeller has "flat plate" drag is to think of the propeller without the engine.  Imagine you just had a prop mounted to a shaft at the front of a glider.  As you are gliding the prop will be spinning.  Making it spin of course requires some energy.  This is where the drag of the prop comes from.  Just to overcome this prop drag you need to put some power into the prop.



It may also be useful to think about autogyros when thinking about prop disk drag.



So, depending on many factors, a larger prop is not always better.  In general a larger prop is better at lower speed and a smaller prop is better at higher speed.



Mark



--

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Wed Mar 02, 2011 6:59 pm Post subject: Re: KIS TR-1 Propeller

Thanks Mark, so understood. That's why I said the prop has 'netto' thrust with the drag you refer to already subsumed/eliminated when thrust is produced by the prop.



Different of course during deceleration, dive, idle and (god forbid) engine failure.



Regard,

          Alfred

_________________
_________________________________________

mantafs(at)earthlink.net
Guest

Posted: Thu Mar 03, 2011 6:34 pm Post subject: KIS TR-1 Propeller

Hello Alfred,



Actually the drag is not eliminated even when there is thrust.  It is still there and adding to the total drag regardless of the engine power setting.  Maybe you can say that first the engine's power goes to this drag but that would be nothing more than an accounting trick and is not actual.



A better accounting method would be to apply the engineering superposition principal.  Maybe this is what you mean by subsumed.



In ways this is esoteric and maybe I am being pedantic, sorry.



Regards,

Mark

--

ftyoder(at)yoderbuilt.com
Guest

Posted: Thu Mar 03, 2011 7:17 pm Post subject: KIS TR-1 Propeller

If anyone it looking for a new fixed pitch prop you might check out Paul 

Lipps' new design. He has had some pretty impressive results at the Reno Air 

Races.

---

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Fri Mar 04, 2011 12:32 pm Post subject: Re: KIS TR-1 Propeller

Thank you for the pointer Tim.



I looked it up and there appears to be close links between Catto and Lipps.



So, for replacing my now demised Chris Lodge prop I shall consider Catto,  Prince P-tip and Idrovario as candidates.



Catto and Prince props are reasonably priced - don't have info on Idrovario pricing range yet. 



Regards,

            Alfred

_________________
_________________________________________

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Sat Mar 05, 2011 10:19 am Post subject: Re: KIS TR-1 Propeller

Gents,



In late January I created a performance model for the KIS to aid my decision regarding a new propeller. Having consulted with Mark Ketttering off line I am now satisfied that the model is realistic.



Attached a view of the results for a particular point on the flight envelope.



There is one big caveat though and I hope the forum can help with that: I need a power curve for a O-240 or IO-240 engine to ensure that the engine power model is accurate. 



I can only hope that someone on the forum has access to such information.



Anyways, take a look at the results. It seemed to work well enough for my plane (when it was still flying   )



Regards,

            Alfred

TRI-R KIS Airframe + Propeller Drag & Power Model.jpg

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TRI-R KIS Airframe + Propeller Drag & Power Model.jpg

_________________
_________________________________________

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Sun Mar 06, 2011 7:52 am Post subject: Re: KIS TR-1 Propeller

Ok, cancel that question about O-240 engine power curve. I hauled out the Rolls Royce overhaul manual for my engine and found a curve for the friction horse power (up to 22 hp at 2800 rpm). The manual makes it clear that friction horsepower is already discounted when in the rated b.h.p. figure of 130 hp at 2800 rpm. 



So I simply matched a polynomial curve to the friction horse power curve and scaled it to 130 hp. Voila!



Result attached if you are interested. Scaled to suit rated hp, this curve would be quite accurate for the entire O-240 engine family.



Regards,

             Alfred

RollsRoyce O-240 Engine Power Curve.jpg

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BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Mon Mar 07, 2011 10:44 am Post subject: Re: KIS TR-1 Propeller

With the aid of engine data provided by OC the engine power model has now been completed as per attachment.



Note: The charts in manufacturers' documentation often exclude the lower end of the rpm range (below ~1900) and therefore lines in those diagrams will appear to be straighter.

RollsRoyce O-240 Engine Power Curve.jpg

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bakerocb

Joined: 15 Jan 2006
Posts: 727
Location: FAIRFAX VA

Posted: Wed Mar 09, 2011 1:13 pm Post subject: KIS TR-1 Propeller

3/9/2011



Hello Alfred, Message received. I'll try.



There are some rather valid reasons for resubjecting or, as some may 

consider it, refining message subjects to show more accurate message 

content:



1) The initial message may be mostly on one subject, then someone will 

respond to that initial message including an off shoot subject and the next 

thing we know messages that deal only with, say flap positioning, are flying 

back and forth still under the intial subject of propeller performance.



This would make it very difficult to research the subject of flap 

positioning if one were doing a message subject only search as opposed to 

doing a message content search.



Bil Schertz, the founder and great guru of the original KIS list before it 

was shifted over to Matronics, was frequently reminding us to keep message 

subject focused on message content. Back then we did not have available the 

sophisticated message content search capability that currently exists within 

the Matronics system.



2) The initial message may just identify the airplane as a KIS with no 

specificity regarding whether the 2 seat or 4 seat, or tail dragger versus 

tricycle gear version was being discussed. This created confusion on many 

occasions and the sooner the clarification was made the better.



3) Sometimes the initial poster will use non standard / unfamiliar / wrong 

(from a widely accepted usage view point) terminology in the posting subject 

line such as "dust cover" instead of "glare shield" or "zero time engine" 

instead of "zero time SMOH (Since Major Over Haul)" and it is not entirely 

helpful to continue to use that initial misleading subject for the life of 

the thread (or eternity as the case may be).



On balance my preference seems to lean toward accurate communication and 

future search relevance being of more long range value than near term ease 

in just following a current thread subject path no matter how misleading the 

subject has become.



OC



================================================================

From: "Alfred Prosser" <aprosser(at)teledynamix.com>

To: <bakerocb(at)cox.net>

Sent: Wednesday, March 09, 2011 11:26 AM

Subject: RE: KIS TR-1 Propeller

 	  Quote: 	
		   Hi OC,



 If you don't mind, please don't start new threads on the forum when 

 responding to messages in already existing threads? It just

 breaks the flow of things and adds clutter where there need not be any. No 

 harm done in just asking.



 Examples of this recently include:

 KIS TR-1 Gear Gap

 KIS TR-1 Propeller - attachment

 PORT SIDE FAIRING

 KIS Landings



 Regards,

                 Alfred

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Sat Mar 12, 2011 1:10 pm Post subject: Re: KIS TR-1 Propeller

Light a the end of the tunnel! ... and about time too )



In late January I started exploring to find the best replacement propeller configuration for the recently acquired KIS TR-1. The objective is to replace the old 2â€“blade 68 x 69 inch â€˜cruiseâ€™ prop with a new prop which will markedly improve low speed climb performance after take-off at full weight.  It turns out that the new prop should be a 3â€“blade 61 x 64 inch â€˜climbâ€™ propeller. The insights gained from these studies have turned upside down all notions I previously held regarding what may or may not constitute an optimal propeller.



Initially I was quite ambivalent about 3-bladed props, but results of the comprehensive performance modeling exercise showed conclusively that a 3-blade prop offers significant comparative performance gains at low speed and also at high altitude (i.e. high density altitudes) â€“ with only a small sacrifice in top end speed. This follows from the fact that an 8-fold increase in power is required for a given speed increase. Trading power for top end speed is therefore not a very effective use of power unless you have oodles to spare â€¦ thinking of Scott here ;o). For us lesser mortals with engines cranking out 130hp or less (at best) it may be sensible to forgo a few knots at the top end (~ 5 knots ) in order to gain a bucketload of spare power to support much improved acceleration and climb performance at the lower end of the speed range in combination with better performance at high density altitudes. 



For general interest, and for others who also have a problem with sluggish takeoffs, the findings are described below with reference to the attached diagram. From previous communications about propeller performance it seems that many KIS TR-1 planes are fitted with 68 or 69 inch pitch props.  Those owners my find the information below particularly relevant.



For actual propellers the choice is still between Prince P-tip, Catto and Idrovario.



Kind regards,

                         Alfred

The old (61 x 69â€) and the new (61 x 64â€) propellers are compared for three typical operating points:

A)	Climbing after take-off  nominal MSL

B)	Level flight at low altitude (nominal MSL)

C)	Flight at 7500 feet (or equivalent altitude where only 75% of engine power remains) 



Notes: 	(i) Green arrowhead lines connect the tips of the three pairs of old vs new performance comparison lines on the diagram.

(ii) Full throttle B.H.P. curve information supplied by OC Baker was instrumental in making it possible to complete the analysis.

(iii) Although I refer to the new prop as a â€˜climbâ€™ prop it cruises perfectly well â€“ the distinction is merely in name, not in application.

(iv) Brake specific fuel consumption does not vary by much over the RPM range of interest. Refer http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption



A)	Climbing after takeoff.

With the old prop, engine rpm tops out at less than 2750 in level flight at low level. Upon starting to climb the rpm then drops â€“ to just below 2400 rpm for climbing at 400 ft/min. When operating at this point, only 91% of the available engine power can be accessed. The rpm drops despite WOT and the operating point slides to the left and downward on the â€˜full throttleâ€™ b.h.p. curve for MSL â€“ shedding power along the way.  [Refer to the uppermost bhp curve in the diagram.]

Because it is so important to retain access to all of the power that the engine can deliver, the new prop has smaller diameter (less torque) and finer pitch (lower blade loading). It allows 2800 rpm to be maintained whilst climbing at 400 ft/min.  For the O-240 engine this produces an extra 12hp in the climb compared to the old prop â€“ and 12 horses can give the TR-1 a goodly lift.

 With the new prop one can truly cruise and climb well at the same time. If WOT is used, the climb rate must exceed  400 ft/min to avoid over-revving. Correct handling of the throttle to prevent over-revving is essential. (A rpm monitor and alarming device will be installed.) The climb rate can of course be increased so that the rpm drops to ~2400 â€“ as for the old prop. The resultant climb rate is then just about double that of the old prop.  At MSL and 2400 rpm, the new prop will apparently sustain a cruise + climb combination of  122 kt + 780 ft/min. As altitude increases the climb rate could be steadily relaxed to maintain the speed.   



B)	Level flight at low altitude.

In level flight at low altitude the old prop could not achieve maximum rpm of 2800 and dropped to 2400 rpm and below when climbing at 400 ft/min. In stark contrast, the new prop could be over-revved in level flight up to altitude of  ~8000 feet. This is an unavoidable side-effect if one desires to have the option to extract all the power the engine can deliver â€“ essential for operating at â€˜hot & highâ€™ fields where density altitude routinely exceeds 8000 feet. During the cruise climb, rpm must be maintained at 2800 or preferably a little less. (If cooled properly, the Rolls Royce O-240-E is rated for continuous operation at 2800 rpm â€“ not that one would do that all the time.)  



C)	Flight at 7500 feet.

At this higher altitude, only 75% of the original engine power remains â€“ and that only if 2800 rpm can be maintained. Reduction of rpm below 2800 results in less power being accessible. [Refer the middle tier â€˜full throttleâ€™ curve in diagram below.]  It can be seen that the maximum power available to the old prop with WOT in level flight was a mere 70%. The effect of climbing is to further decrease the rpm despite the WOT. The resulting loss of power seriously inhibits climb performance at this altitude. The new prop enables access to all the power still available at this level and provides the freedom to operate at any chosen point on that â€˜full throttleâ€™ bhp curve. In particular, climb performance is markedly improved. The same applies to all altitudes below ~8000 feet.

Climb vs Cruise propeller comparison for KIS TR-1.jpg

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Climb vs Cruise propeller comparison for KIS TR-1.jpg

_________________
_________________________________________

galinhdz(at)gmail.com
Guest

Posted: Sat Mar 12, 2011 8:55 pm Post subject: KIS TR-1 Propeller

THANKS for the write-up. Now I can use this to justify to my wife me

getting the 3-bladed prop I want.. )



On Sat, Mar 12, 2011 at 3:10 PM, BlueSkyFlier <bleuskyfly(at)teledynamix.com>wrote:



[quote] 

 >



 Light a the end of the tunnel! ... and about time too )



 In late January I started exploring to find the best replacement propeller

 configuration for the recently acquired KIS TR-1. The objective is to

 replace the old 2–blade 68 x 69 inch ‘cruise’ prop with a new prop which

 will markedly improve low speed climb performance after take-off at full

 weight.  It turns out that the new prop should be a 3–blade 61 x 64 inch

 ‘climb’ propeller. The insights gained from these studies have turned upside

 down all notions I previously held regarding what may or may not constitute

 an optimal propeller.



 Initially I was quite ambivalent about 3-bladed props, but results of the

 comprehensive performance modeling exercise showed conclusively that a

 3-blade prop offers significant comparative performance gains at low speed

 and also at high altitude (i.e. high density altitudes) – with only a small

 sacrifice in top end speed. This follows from the fact that an 8-fold

 increase in power is required for a given speed increase. Trading power for

 top end speed is therefore not a very effective use of power unless you have

 oodles to spare … thinking of Scott here ;o). For us lesser mortals with

 engines cranking out 130hp or less (at best) it may be sensible to forgo a

 few knots at the top end (~ 5 knots ) in order to gain a bucketload of spare

 power to support much improved acceleration and climb performance at the

 lower end of the speed range in combination with better performance at high

 density altitudes.



 For general interest, and for others who also have a problem with sluggish

 takeoffs, the findings are described below with reference to the attached

 diagram. From previous communications about propeller performance it seems

 that many KIS TR-1 planes are fitted with 68 or 69 inch pitch props.  Those

 owners my find the information below particularly relevant.



 For actual propellers the choice is still between Prince P-tip, Catto and

 Idrovario.



 Kind regards,

                         Alfred

 The old (61 x 69”) and the new (61 x 64”) propellers are compared for three

 typical operating points:

 A)      Climbing after take-off  nominal MSL

 B)      Level flight at low altitude (nominal MSL)

 C)      Flight at 7500 feet (or equivalent altitude where only 75% of

 engine power remains)



 Notes:  (i) Green arrowhead lines connect the tips of the three pairs of

 old vs new performance comparison lines on the diagram.

 (ii) Full throttle B.H.P. curve information supplied by OC Baker was

 instrumental in making it possible to complete the analysis.

 (iii) Although I refer to the new prop as a ‘climb’ prop it cruises

 perfectly well – the distinction is merely in name, not in application.

 (iv) Brake specific fuel consumption does not vary by much over the RPM

 range of interest. Refer

 http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption



 A)      Climbing after takeoff.

 With the old prop, engine rpm tops out at less than 2750 in level flight at

 low level. Upon starting to climb the rpm then drops – to just below 2400

 rpm for climbing at 400 ft/min. When operating at this point, only 91% of

 the available engine power can be accessed. The rpm drops despite WOT and

 the operating point slides to the left and downward on the ‘full throttle’

 b.h.p. curve for MSL – shedding power along the way.  [Refer to the

 uppermost bhp curve in the diagram.]

 Because it is so important to retain access to all of the power that the

 engine can deliver, the new prop has smaller diameter (less torque) and

 finer pitch (lower blade loading). It allows 2800 rpm to be maintained

 whilst climbing at 400 ft/min.  For the O-240 engine this produces an extra

 12hp in the climb compared to the old prop – and 12 horses can give the TR-1

 a goodly lift.

  With the new prop one can truly cruise and climb well at the same time. If

 WOT is used, the climb rate must exceed  400 ft/min to avoid over-revving

gbrighton(at)skymesh.com.
Guest

Posted: Sun Mar 13, 2011 4:06 am Post subject: KIS TR-1 Propeller

For what its worth ... i have a wooden 3blade gnd adjust prop ...blade 

length is 31''  so spose that makes it a 62''  ..was pretty happy with it .. 

not sure what its limits will be with the new engine ...?



Graham

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Mon Mar 14, 2011 2:43 am Post subject: Re: KIS TR-1 Propeller

Chuckle chuckle ...  



Hi Galin. I was thinking of you when I did the write-up because I did previously say to you that a 3-blade prop is rarely if ever better than the 2-blade -- that statement still holds if both prop types have the same pitch.



In such case the one advantage of the 3-blade is that the lower power loading per blade reduces the lift coefficent on the blades. Therefore the 3-blade stops cavitating (starts to 'bite' properly) at lower forward speed than a 2-blade generating the same thrust. Takeoff acceleration therefore benefits. The price to pay for that benefit is the higher parasitic drag of the 3-blade prop.



In any case, reducing the propeller pitch is what really makes the difference and is essential to release the extra RPM needed to tap into the top end of the 'full throttle' curves at any % remaining power. The parasitic drag penalty is offset by reducing the diameter accordingly.



One important observation from these studies is that steeply banked turns should be given a wide berth in the KIS TR-1 if you have less than 130 hp up front coupled with a propeller pitch in the high 60"s. Anything more than 55 degree bank has the potential to really spoil you day - and everyone else's too.



[Bonbons for those who spot the obvious little booboo in two of the labels on the diagram )] 



Cheers,

           Alfred

_________________
_________________________________________

bakerocb

Joined: 15 Jan 2006
Posts: 727
Location: FAIRFAX VA

Posted: Tue Mar 15, 2011 4:14 am Post subject: KIS TR-1 Propeller

3/15/2010



Hello Alfred, You wrote: "One important observation from these studies is 

that steeply banked turns should be given a wide berth in the KIS TR-1 if 

you have less than 130 hp up front coupled with a propeller pitch in the 

high 60"s. Anything more than 55 degree bank has the potential to really 

spoil you day - and everyone else's too."



I don't understand:



A) What bad thing(s) are supposed to happen with more than 55 degree angle 

of bank?



B) Why are the engine horsepower and propeller pitch specifically 

responsible for these bad things?



Thanks,



OC



PS: I routinely practice 60 degree angle of bank turns with my TCM 125 HP 

IO-240 B9B powered KIS TR-1 that has a 68 inch diameter by 69 inch pitch 

Prince P tip propeller. I use 100 knots indicated airspeed (which I consider 

V sub a, or maneuvering airspeed for my plane) and just a bit more than 

2,000 RPM (which is not nearly max engine horsepower output) in order to 

maintain altitude during the turn.



It is a fairly demanding exercise, particularly during entry to and exit 

from the turn to avoid altitude excursions, but my decrepit 78 year old hand 

eye coordination has managed to avoid anything that I would call bad so far. 

My goal is to meet the US FAA Commercial Pilot Practical Test Standards 

copied here:



A. TASK: STEEP TURNS (ASEL and ASES)

REFERENCES: FAA-H-8083-3; POH/AFM.

Objective. To determine that the applicant:

1. Exhibits knowledge of the elements related to steep turns.

2. Establishes the manufacturer's recommended airspeed or if one

is not stated, a safe airspeed not to exceed VA.

3. Rolls into a coordinated 360° steep turn with at least a 50° bank,

followed by a 360° steep turn in the opposite direction.

4. Divides attention between airplane control and orientation.

5. Maintains the entry altitude, ±100 feet (30 meters), airspeed,

±10 knots, bank, ±5°; and rolls out on the entry heading, ±10°.



=================================================================

From: "BlueSkyFlier" <bleuskyfly(at)teledynamix.com>

To: <kis-list(at)matronics.com>

Sent: Monday, March 14, 2011 6:43 AM

Subject: Re: KIS TR-1 Propeller

 	  Quote: 	
		   

 <bleuskyfly(at)teledynamix.com>



 Chuckle chuckle ... [Laughing]



 Hi Galin. I was thinking of you when I did the write-up because I did 

 previously say to you that a 3-blade prop is rarely if ever better than 

 the 2-blade -- that statement still holds if both prop types have the same 

 pitch.



 In such case the one advantage of the 3-blade is that the lower power 

 loading per blade reduces the lift coefficent on the blades. Therefore the 

 3-blade stops cavitating (starts to 'bite' properly) at lower forward 

 speed than a 2-blade generating the same thrust. Takeoff acceleration 

 therefore benefits. The price to pay for that benefit is the higher 

 parasitic drag of the 3-blade prop.



 In any case, reducing the propeller pitch is what really makes the 

 difference and is essential to release the extra RPM needed to tap into 

 the top end of the 'full throttle' curves at any % remaining power. The 

 parasitic drag penalty is offset by reducing the diameter accordingly.



 One important observation from these studies is that steeply banked turns 

 should be given a wide berth in the KIS TR-1 if you have less than 130 hp 

 up front coupled with a propeller pitch in the high 60"s. Anything more 

 than 55 degree bank has the potential to really spoil you day - and 

 everyone else's too.



 [Bonbons for those who spot the obvious little booboo in two of the labels 

 on the diagram )]



 Cheers,

           Alfred

richard_trickel(at)yahoo.
Guest

Posted: Tue Mar 15, 2011 5:37 am Post subject: KIS TR-1 Propeller

Alfred

 I agree with O.C.  I and may others have done what is considered aerobatic manuvers with no grave dangers.. I know of one South African who did snap rolls on take off.  ( He has a bigger set than I do)  60 degrees should be no problem.  I do know the plane becomes very quiet upside down and I get a little dirt in my eyes:)

 Rich



--- On Tue, 3/15/11, bakerocb(at)cox.net <bakerocb(at)cox.net> wrote:



  	  Quote: 	
		  

From: bakerocb(at)cox.net <bakerocb(at)cox.net>

Subject: Re: Re: KIS TR-1 Propeller

To: kis-list(at)matronics.com, bleuskyfly(at)teledynamix.com

Date: Tuesday, March 15, 2011, 12:11 PM



 --> KIS-List message posted by: <bakerocb(at)cox.net (bakerocb(at)cox.net)>



3/15/2010



Hello Alfred, You wrote: "One important observation from these studies is that steeply banked turns should be given a wide berth in the KIS TR-1 if you have less than 130 hp up front coupled with a propeller pitch in the high 60"s. Anything more than 55 degree bank has the potential to really spoil you day - and everyone else's too."



I don't understand:



A) What bad thing(s) are supposed to happen with more than 55 degree angle of bank?



B) Why are the engine horsepower and propeller pitch specifically responsible for these bad things?



Thanks,



OC



PS: I routinely practice 60 degree angle of bank turns with my TCM 125 HP IO-240 B9B powered KIS TR-1 that has a 68 inch diameter by 69 inch pitch Prince P tip  propeller. I use 100 knots indicated airspeed (which I consider V sub a, or maneuvering airspeed for my plane) and just a bit more than 2,000 RPM (which is not nearly max engine horsepower output) in order to maintain altitude during the turn.



It is a fairly demanding exercise, particularly during entry to and exit from the turn to avoid altitude excursions, but my decrepit 78 year old hand eye coordination has managed to avoid anything that I would call bad so far. My goal is to meet the US FAA Commercial Pilot Practical Test Standards copied here:



A. TASK: STEEP TURNS (ASEL and ASES)

REFERENCES: FAA-H-8083-3; POH/AFM.

Objective. To determine that the applicant:

1. Exhibits knowledge of the elements related to steep turns.

2. Establishes the manufacturer's recommended airspeed or if one

is not stated, a safe airspeed not to exceed VA.

3. Rolls into a coordinated 360° steep turn with at least a 50° bank,

followed by  a 360° steep turn in the opposite direction.

4. Divides attention between airplane control and orientation.

5. Maintains the entry altitude, ±100 feet (30 meters), airspeed,

±10 knots, bank, ±5°; and rolls out on the entry heading, ±10°.



===============

From: "BlueSkyFlier" <bleuskyfly(at)teledynamix.com (bleuskyfly(at)teledynamix.com)>

To: <kis-list(at)matronics.com (kis-list(at)matronics.com)>

Sent: Monday, March 14, 2011 6:43 AM

Subject: Re: KIS TR-1 Propeller

 	  Quote: 	
		   --> KIS-List message posted by: "BlueSkyFlier" <bleuskyfly(at)teledynamix.com (bleuskyfly(at)teledynamix.com)>

 

 Chuckle chuckle ... [Laughing]

 

 Hi Galin. I was thinking of you when I did the write-up because I did previously say to you that a 3-blade prop is rarely if ever better than the 2-blade -- that statement still holds if both prop types have the same pitch.

 

 In such case the one advantage of the 3-blade is that the lower power loading per blade reduces the lift coefficent on the blades. Therefore the 3-blade stops cavitating (starts to 'bite' properly) at lower forward speed than a 2-blade generating the same thrust. Takeoff acceleration therefore benefits. The price to pay for that benefit is the higher parasitic drag of the 3-blade prop.

 

 In any case, reducing the propeller pitch is what really makes the difference and is essential to release the extra RPM needed to tap into the top end of the 'full throttle'  curves at any % remaining power. The parasitic drag penalty is offset by reducing the diameter accordingly.

 

 One important observation from these studies is that steeply banked turns should be given a wide berth in the KIS TR-1 if you have less than 130 hp up front coupled with a propeller pitch in the high 60"s. Anything more than 55 degree bank has the potential to really spoil you day - and everyone else's too.

 

 [Bonbons for those who spot the obvious little booboo in two of the labels on the diagram )]

 

 Cheers,

      htthttp://forums.matronics.com/" target=_blank>http://forums.matronics.com


	


	


         [quote][b]

sstearns2(at)yahoo.com
Guest

Posted: Tue Mar 15, 2011 7:04 am Post subject: KIS TR-1 Propeller

I've rolled my airplane a few times now without any issues, but I think what Alfred is getting at is that with only 130HP you probably cannot do a sustained 55+ degree bank turn at altitude without the speed bleeding off a lot.

  

 Scott



--- On Tue, 3/15/11, Richard Trickel <richard_trickel(at)yahoo.com> wrote:



  	  Quote: 	
		  

From: Richard Trickel <richard_trickel(at)yahoo.com>

Subject: Re: Re: KIS TR-1 Propeller

To: kis-list(at)matronics.com

Date: Tuesday, March 15, 2011, 6:34 AM



      Alfred

 I agree with O.C.  I and may others have done what is considered aerobatic manuvers with no grave dangers.. I know of one South African who did snap rolls on take off.  ( He has a bigger set than I do)  60 degrees should be no problem.  I do know the plane becomes very quiet upside down and I get a little dirt in my eyes:)

 Rich



--- On Tue, 3/15/11, bakerocb(at)cox.net <bakerocb(at)cox.net> wrote:



  	  Quote: 	
		  

From: bakerocb(at)cox.net <bakerocb(at)cox.net>

Subject: Re: Re: KIS TR-1 Propeller

To: kis-list(at)matronics.com, bleuskyfly(at)teledynamix.com

Date: Tuesday, March 15, 2011, 12:11 PM



 --> KIS-List message posted by: <bakerocb(at)cox.net>



3/15/2010



Hello Alfred, You wrote: "One important observation from these studies is that steeply banked turns should be given a wide berth in the KIS TR-1 if you have less than 130 hp up front coupled with a propeller pitch in the high 60"s. Anything more than 55 degree bank has the potential to really spoil you day - and everyone else's too."



I don't understand:



A) What bad thing(s) are supposed to happen with more than 55 degree angle of bank?



B) Why are the engine horsepower and propeller pitch specifically responsible for these bad things?



Thanks,



OC



PS: I routinely practice 60 degree angle of bank turns with my TCM 125 HP IO-240 B9B powered KIS TR-1 that has a 68 inch diameter by 69 inch pitch Prince  P tip propeller. I use 100 knots indicated airspeed (which I consider V sub a, or maneuvering airspeed for my plane) and just a bit more than 2,000 RPM (which is not nearly max engine horsepower output) in order to maintain altitude during the turn.



It is a fairly demanding exercise, particularly during entry to and exit from the turn to avoid altitude excursions, but my decrepit 78 year old hand eye coordination has managed to avoid anything that I would call bad so far. My goal is to meet the US FAA Commercial Pilot Practical Test Standards copied here:



A. TASK: STEEP TURNS (ASEL and ASES)

REFERENCES: FAA-H-8083-3; POH/AFM.

Objective. To determine that the applicant:

1. Exhibits knowledge of the elements related to steep turns.

2. Establishes the manufacturer's recommended airspeed or if one

is not stated, a safe airspeed not to exceed VA.

3. Rolls into a coordinated 360° steep turn with at least a 50°  bank,

followed by a 360° steep turn in the opposite direction.

4. Divides attention between airplane control and orientation.

5. Maintains the entry altitude, ±100 feet (30 meters), airspeed,

±10 knots, bank, ±5°; and rolls out on the entry heading, ±10°.



===============

From: "BlueSkyFlier" <bleuskyfly(at)teledynamix.com>

To: <kis-list(at)matronics.com>

Sent: Monday, March 14, 2011 6:43 AM

Subject: Re: KIS TR-1 Propeller

 	  Quote: 	
		   --> KIS-List message posted by: "BlueSkyFlier" <bleuskyfly(at)teledynamix.com>

 

 Chuckle chuckle ...  [Laughing]

 

 Hi Galin. I was thinking of you when I did the write-up because I did previously say to you that a 3-blade prop is rarely if ever better than the 2-blade -- that statement still holds if both prop types have the same pitch.

 

 In such case the one advantage of the 3-blade is that the lower power loading per blade reduces the lift coefficent on the blades. Therefore the 3-blade stops cavitating (starts to 'bite' properly) at lower forward speed than a 2-blade generating the same thrust. Takeoff acceleration therefore benefits. The price to pay for that benefit is the higher parasitic drag of the 3-blade prop.

 

 In any case, reducing the propeller pitch is what really makes the difference and is essential to release the extra RPM needed to tap into the top end of the 'full throttle' curves at any % remaining power. The parasitic drag penalty is offset by reducing the diameter accordingly.

  

 One important observation from these studies is that steeply banked turns should be given a wide berth in the KIS TR-1 if you have less than 130 hp up front coupled with a propeller pitch in the high 60"s. Anything more than 55 degree bank has the potential to really spoil you day - and everyone else's too.

 

 [Bonbons for those who spot the obvious little booboo in two of the labels on the diagram )]

 

 Cheers,

      htthttp://forums.matronics.com/" target=_blank>http://forums.matronics.com 


	


	


 	  Quote: 	
		  



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et=_blank>http://forums.matronics.com

llow target=_blank>http://www.matronics.com/contribution



	


	


         [quote][b]

richard_trickel(at)yahoo.
Guest

Posted: Tue Mar 15, 2011 9:40 am Post subject: KIS TR-1 Propeller

Scott

 Yea your going to slow down but i think you can maintain altitude.  I would not try it at 100 ft. but in practice it should be little problem

 Rich



--- On Tue, 3/15/11, Scott Stearns <sstearns2(at)yahoo.com> wrote:



  	  Quote: 	
		  

From: Scott Stearns <sstearns2(at)yahoo.com>

Subject: Re: Re: KIS TR-1 Propeller

To: kis-list(at)matronics.com

Date: Tuesday, March 15, 2011, 3:03 PM



      I've rolled my airplane a few times now without any issues, but I think what Alfred is getting at is that with only 130HP you probably cannot do a sustained 55+ degree bank turn at altitude without the speed bleeding off a lot.

  

 Scott



--- On Tue, 3/15/11, Richard Trickel <richard_trickel(at)yahoo.com> wrote:



  	  Quote: 	
		  

From: Richard Trickel <richard_trickel(at)yahoo.com>

Subject: Re: Re: KIS TR-1 Propeller

To: kis-list(at)matronics.com

Date: Tuesday, March 15, 2011, 6:34 AM



      Alfred

 I agree with O.C.  I and may others have done what is considered aerobatic manuvers with no grave dangers.. I know of one South African who did snap rolls on take off.  ( He has a bigger set than I do)  60 degrees should be no problem.  I do know the plane becomes very quiet upside down and I get a little dirt in my eyes:)

 Rich



--- On Tue, 3/15/11, bakerocb(at)cox.net <bakerocb(at)cox.net> wrote:



  	  Quote: 	
		  

From: bakerocb(at)cox.net <bakerocb(at)cox.net>

Subject: Re: Re: KIS TR-1 Propeller

To: kis-list(at)matronics.com, bleuskyfly(at)teledynamix.com

Date: Tuesday, March 15, 2011, 12:11 PM



 --> KIS-List message posted by: <bakerocb(at)cox.net>



3/15/2010



Hello Alfred, You wrote: "One important observation from these studies is that steeply banked turns should be given a wide berth in the KIS TR-1 if you have less than 130 hp up front coupled with a propeller pitch in the high 60"s. Anything more than 55 degree bank has the potential to really spoil you day - and everyone else's too."



I don't understand:



A) What bad thing(s) are supposed to happen with more than 55 degree angle of bank?



B) Why are the engine horsepower and propeller pitch specifically responsible for these bad things?



Thanks,



OC



PS: I routinely practice 60 degree angle of bank turns with my TCM 125 HP IO-240 B9B powered KIS TR-1 that has a 68 inch diameter by 69 inch pitch Prince  P tip propeller. I use 100 knots indicated airspeed (which I consider V sub a, or maneuvering airspeed for my plane) and just a bit more than 2,000 RPM (which is not nearly max engine horsepower output) in order to maintain altitude during the turn.



It is a fairly demanding exercise, particularly during entry to and exit from the turn to avoid altitude excursions, but my decrepit 78 year old hand eye coordination has managed to avoid anything that I would call bad so far. My goal is to meet the US FAA Commercial Pilot Practical Test Standards copied here:



A. TASK: STEEP TURNS (ASEL and ASES)

REFERENCES: FAA-H-8083-3; POH/AFM.

Objective. To determine that the applicant:

1. Exhibits knowledge of the elements related to steep turns.

2. Establishes the manufacturer's recommended airspeed or if one

is not stated, a safe airspeed not to exceed VA.

3. Rolls into a coordinated 360° steep turn with at least a 50°  bank,

followed by a 360° steep turn in the opposite direction.

4. Divides attention between airplane control and orientation.

5. Maintains the entry altitude, ±100 feet (30 meters), airspeed,

±10 knots, bank, ±5°; and rolls out on the entry heading, ±10°.



===============

From: "BlueSkyFlier" <bleuskyfly(at)teledynamix.com>

To: <kis-list(at)matronics.com>

Sent: Monday, March 14, 2011 6:43 AM

Subject: Re: KIS TR-1 Propeller

 	  Quote: 	
		   --> KIS-List message posted by: "BlueSkyFlier" <bleuskyfly(at)teledynamix.com>

 

 Chuckle chuckle ...  [Laughing]

 

 Hi Galin. I was thinking of you when I did the write-up because I did previously say to you that a 3-blade prop is rarely if ever better than the 2-blade -- that statement still holds if both prop types have the same pitch.

 

 In such case the one advantage of the 3-blade is that the lower power loading per blade reduces the lift coefficent on the blades. Therefore the 3-blade stops cavitating (starts to 'bite' properly) at lower forward speed than a 2-blade generating the same thrust. Takeoff acceleration therefore benefits. The price to pay for that benefit is the higher parasitic drag of the 3-blade prop.

 

 In any case, reducing the propeller pitch is what really makes the difference and is essential to release the extra RPM needed to tap into the top end of the 'full throttle' curves at any % remaining power. The parasitic drag penalty is offset by reducing the diameter accordingly.

  

 One important observation from these studies is that steeply banked turns should be given a wide berth in the KIS TR-1 if you have less than 130 hp up front coupled with a propeller pitch in the high 60"s. Anything more than 55 degree bank has the potential to really spoil you day - and everyone else's too.

 

 [Bonbons for those who spot the obvious little booboo in two of the labels on the diagram )]

 

 Cheers,

      htthttp://forums.matronics.com/" target=_blank>http://forums.matronics.com 


	


	


 	  Quote: 	
		  



=nofollow target=_blank>http://www.matronics.com/Navigator?KIS-List

et=_blank>http://forums.matronics.com

llow target=_blank>http://www.matronics.com/contribution



	


	


 	  Quote: 	
		  



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et=_blank>http://forums.matronics.com

llow target=_blank>http://www.matronics.com/contribution



	


	


         [quote][b]

BlueSkyFlier

Joined: 27 Jan 2011
Posts: 74
Location: UK

Posted: Tue Mar 15, 2011 10:56 am Post subject: Re: KIS TR-1 Propeller

Whoa guys! The intention was not to insult the plane. I own one too, remember.



Once you have done your HASELL check, no problem. We all need to do those turns to pass the checks. I also did a snap roll recently in training â€“ sussing out where and when she drops a wing in stall speed regime - also when getting too slow in a slip, especially to starboard. No problem with recoveries if you have height. 



The point I'm making (badly so seemingly) is that it puts you into a region of the flight envelope where you have preciously little spare performance to get out of trouble if you don't have height to spare. To answer OCâ€™s question, thatâ€™s why engine power and prop pitch comes into the equation. Rich and Scott hit the nail on the head. With current parameters, the model indicates that - with 125hp engine and 69â€ pitch prop - it would be difficult to sustain a 60 degree turn above 3500 feet altitude.



I propped the propeller and power configuration for OCâ€™s plane into the model. Results in diagram attached below match what he reported â€“ the speed he referred to would be IAS. With the graph based on TAS, it is of course offset slightly to the right from the 100 kts reported by OC. The dashed purple line is RPM (divided by ten â€“ on lefthand scale).  Good to have another confirmation that the model works.



Cheers,

                Alfred

Sixty degree turn in KIS TR-1.jpg

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