---------------------------------------------------------- KIS-List Digest Archive --- Total Messages Posted Tue 03/15/11: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:14 AM - Re: Re: KIS TR-1 Propeller () 2. 06:37 AM - Re: Re: KIS TR-1 Propeller (Richard Trickel) 3. 08:04 AM - Re: Re: KIS TR-1 Propeller (Scott Stearns) 4. 10:40 AM - Re: Re: KIS TR-1 Propeller (Richard Trickel) 5. 11:58 AM - Re: KIS TR-1 Propeller (BlueSkyFlier) 6. 12:51 PM - Re: KIS TR-1 Propeller (BlueSkyFlier) 7. 12:53 PM - Re: KIS TR-1 Propeller (BlueSkyFlier) 8. 01:45 PM - Re: Re: KIS TR-1 Propeller (Galin Hernandez) 9. 02:06 PM - Re: KIS TR-1 Propeller (BlueSkyFlier) 10. 03:04 PM - Re: KIS TR-1 Propeller (BlueSkyFlier) ________________________________ Message 1 _____________________________________ Time: 05:14:30 AM PST US From: Subject: Re: KIS-List: Re: 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" Sent: Monday, March 14, 2011 6:43 AM Subject: KIS-List: Re: KIS TR-1 Propeller > > > 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 :o)] > > Cheers, > Alfred ________________________________ Message 2 _____________________________________ Time: 06:37:41 AM PST US From: Richard Trickel Subject: Re: KIS-List: Re: KIS TR-1 Propeller Alfred I agree with O.C.- I and may others have done what is considered aerobati c 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 shoul d 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@cox.net wrote: From: bakerocb@cox.net Subject: Re: KIS-List: Re: KIS TR-1 Propeller 3/15/2010 Hello Alfred, You wrote: "One important observation from these studies is t hat steeply banked turns should be given a wide berth in the KIS TR-1 if yo u 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 responsib le for these bad things? Thanks, OC PS: I routinely practice 60 degree angle of bank turns with my TCM 125 HP I O-240 B9B powered KIS TR-1 that has a 68 inch diameter by 69 inch pitch Pri nce 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 2,00 0 RPM (which is not nearly max engine horsepower output) in order to mainta in altitude during the turn. It is a fairly demanding exercise, particularly during entry to and exit fr om 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 c opied 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=B0 steep turn with at least a 50=B0 bank, followed by a 360=B0 steep turn in the opposite direction. 4. Divides attention between airplane control and orientation. 5. Maintains the entry altitude, =B1100 feet (30 meters), airspeed, =B110 knots, bank, =B15=B0; and rolls out on the entry heading, =B110=B0. ============== From: "BlueSkyFlier" Sent: Monday, March 14, 2011 6:43 AM Subject: KIS-List: Re: KIS TR-1 Propeller m> > > Chuckle chuckle ... [Laughing] > > Hi Galin. I was thinking of you when I did the write-up because I did pre viously 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 loa ding per blade reduces the lift coefficent on the blades. Therefore the 3-b lade stops cavitating (starts to 'bite' properly) at lower forward speed th an a 2-blade generating the same thrust. Takeoff acceleration therefore ben efits. The price to pay for that benefit is the higher parasitic drag of th e 3-blade prop. > > In any case, reducing the propeller pitch is what really makes the differ ence and is essential to release the extra RPM needed to tap into the top e nd of the 'full throttle' curves at any % remaining power. The parasitic dr ag 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 tha n 55 degree bank has the potential to really spoil you day - and everyone e lse's too. > > [Bonbons for those who spot the obvious little booboo in two of the label s on the diagram :o)] > > Cheers, >- - - - ---Alfred le, List Admin. =0A=0A=0A ________________________________ Message 3 _____________________________________ Time: 08:04:49 AM PST US From: Scott Stearns Subject: Re: KIS-List: Re: KIS TR-1 Propeller I've rolled my airplane a few times now without any issues, but I think wha t Alfred is getting at is that with only 130HP you probably cannot do a sus tained-55+ degree bank turn at altitude without the speed bleeding off a lot. - Scott --- On Tue, 3/15/11, Richard Trickel wrote: From: Richard Trickel Subject: Re: KIS-List: Re: KIS TR-1 Propeller Alfred I agree with O.C.- I and may others have done what is considered aerobati c 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 shoul d 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@cox.net wrote: From: bakerocb@cox.net Subject: Re: KIS-List: Re: KIS TR-1 Propeller 3/15/2010 Hello Alfred, You wrote: "One important observation from these studies is t hat steeply banked turns should be given a wide berth in the KIS TR-1 if yo u 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 responsib le for these bad things? Thanks, OC PS: I routinely practice 60 degree angle of bank turns with my TCM 125 HP I O-240 B9B powered KIS TR-1 that has a 68 inch diameter by 69 inch pitch Pri nce 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 2,00 0 RPM (which is not nearly max engine horsepower output) in order to mainta in altitude during the turn. It is a fairly demanding exercise, particularly during entry to and exit fr om 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 c opied 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=B0 steep turn with at least a 50=B0 bank, followed by a 360=B0 steep turn in the opposite direction. 4. Divides attention between airplane control and orientation. 5. Maintains the entry altitude, =B1100 feet (30 meters), airspeed, =B110 knots, bank, =B15=B0; and rolls out on the entry heading, =B110=B0. ============== From: "BlueSkyFlier" Sent: Monday, March 14, 2011 6:43 AM Subject: KIS-List: Re: KIS TR-1 Propeller m> > > Chuckle chuckle ... [Laughing] > > Hi Galin. I was thinking of you when I did the write-up because I did pre viously 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 loa ding per blade reduces the lift coefficent on the blades. Therefore the 3-b lade stops cavitating (starts to 'bite' properly) at lower forward speed th an a 2-blade generating the same thrust. Takeoff acceleration therefore ben efits. The price to pay for that benefit is the higher parasitic drag of th e 3-blade prop. > > In any case, reducing the propeller pitch is what really makes the differ ence and is essential to release the extra RPM needed to tap into the top e nd of the 'full throttle' curves at any % remaining power. The parasitic dr ag 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 tha n 55 degree bank has the potential to really spoil you day - and everyone e lse's too. > > [Bonbons for those who spot the obvious little booboo in two of the label s on the diagram :o)] > > Cheers, >- - - htthttp://forums.matronics.com/" target=_blank>http://forums .matronics.com =0A=0A=0A ________________________________ Message 4 _____________________________________ Time: 10:40:15 AM PST US From: Richard Trickel Subject: Re: KIS-List: Re: KIS TR-1 Propeller Scott Yea your going to slow down but i think you can maintain altitude.- I wou ld not try it at 100 ft. but in practice it should be little problem Rich --- On Tue, 3/15/11, Scott Stearns wrote: From: Scott Stearns Subject: Re: KIS-List: Re: KIS TR-1 Propeller I've rolled my airplane a few times now without any issues, but I think wha t Alfred is getting at is that with only 130HP you probably cannot do a sus tained-55+ degree bank turn at altitude without the speed bleeding off a lot. - Scott --- On Tue, 3/15/11, Richard Trickel wrote: From: Richard Trickel Subject: Re: KIS-List: Re: KIS TR-1 Propeller Alfred I agree with O.C.- I and may others have done what is considered aerobati c 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 shoul d 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@cox.net wrote: From: bakerocb@cox.net Subject: Re: KIS-List: Re: KIS TR-1 Propeller 3/15/2010 Hello Alfred, You wrote: "One important observation from these studies is t hat steeply banked turns should be given a wide berth in the KIS TR-1 if yo u 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 responsib le for these bad things? Thanks, OC PS: I routinely practice 60 degree angle of bank turns with my TCM 125 HP I O-240 B9B powered KIS TR-1 that has a 68 inch diameter by 69 inch pitch Pri nce 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 2,00 0 RPM (which is not nearly max engine horsepower output) in order to mainta in altitude during the turn. It is a fairly demanding exercise, particularly during entry to and exit fr om 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 c opied 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=B0 steep turn with at least a 50=B0 bank, followed by a 360=B0 steep turn in the opposite direction. 4. Divides attention between airplane control and orientation. 5. Maintains the entry altitude, =B1100 feet (30 meters), airspeed, =B110 knots, bank, =B15=B0; and rolls out on the entry heading, =B110=B0. ============== From: "BlueSkyFlier" Sent: Monday, March 14, 2011 6:43 AM Subject: KIS-List: Re: KIS TR-1 Propeller m> > > Chuckle chuckle ... [Laughing] > > Hi Galin. I was thinking of you when I did the write-up because I did pre viously 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 loa ding per blade reduces the lift coefficent on the blades. Therefore the 3-b lade stops cavitating (starts to 'bite' properly) at lower forward speed th an a 2-blade generating the same thrust. Takeoff acceleration therefore ben efits. The price to pay for that benefit is the higher parasitic drag of th e 3-blade prop. > > In any case, reducing the propeller pitch is what really makes the differ ence and is essential to release the extra RPM needed to tap into the top e nd of the 'full throttle' curves at any % remaining power. The parasitic dr ag 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 tha n 55 degree bank has the potential to really spoil you day - and everyone e lse's too. > > [Bonbons for those who spot the obvious little booboo in two of the label s on the diagram :o)] > > Cheers, >- - - htthttp://forums.matronics.com/" target=_blank>http://forums .matronics.com =nofollow target=_blank>http://www.matronics.com/Navigator?KIS-List et=_blank>http://forums.matronics.com llow target=_blank>http://www.matronics.com/contribution =0A=0A=0A ________________________________ Message 5 _____________________________________ Time: 11:58:42 AM PST US Subject: KIS-List: Re: KIS TR-1 Propeller From: "BlueSkyFlier" 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 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 OCs question, thats 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 69 pitch prop - it would be difficult to sustain a 60 degree turn above 3500 feet altitude. I propped the propeller and power configuration for OCs plane into the model. Results in diagram attached below match what he reported 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 on lefthand scale). Good to have another confirmation that the model works. Cheers, Alfred -------- _________________________________________ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=333982#333982 Attachments: http://forums.matronics.com//files/sixty_degree_turn_in_kis_tr_1_115.jpg ________________________________ Message 6 _____________________________________ Time: 12:51:49 PM PST US Subject: KIS-List: Re: KIS TR-1 Propeller From: "BlueSkyFlier" And by way of contrast to the above performance in sixty degree turn at 2000 feet, below a 55% degree turn at 3500 feet. Because the cosine function goes to infinity at 90 degrees, don't underestimate how quickly things can get out of hand once you pass the 55 degree mark :o) Regards, Alfred -------- _________________________________________ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=333987#333987 ________________________________ Message 7 _____________________________________ Time: 12:53:53 PM PST US Subject: KIS-List: Re: KIS TR-1 Propeller From: "BlueSkyFlier" Oops! finger trouble. Attachment which should been above now attached ... -------- _________________________________________ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=333988#333988 Attachments: http://forums.matronics.com//files/fifty_five_degree_turn_in_kis_tr_1_168.jpg ________________________________ Message 8 _____________________________________ Time: 01:45:06 PM PST US Subject: Re: KIS-List: Re: KIS TR-1 Propeller From: Galin Hernandez Thanks. I have a KIS4 so it will be a little different but overall the same principal applies On Monday, March 14, 2011, BlueSkyFlier wrote: > > 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 :o)] > > Cheers, > Alfred > > -------- > _________________________________________ > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=333836#333836 > > ________________________________ Message 9 _____________________________________ Time: 02:06:29 PM PST US Subject: KIS-List: Re: KIS TR-1 Propeller From: "BlueSkyFlier" And it is the arc-cosine which goes to infinity of course. Can't talk about the KIS4 Galin - but as far as propellers go the same principles do hold. I'll get back in my cupboard now :) . - Alfred -------- _________________________________________ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=333994#333994 ________________________________ Message 10 ____________________________________ Time: 03:04:15 PM PST US Subject: KIS-List: Re: KIS TR-1 Propeller From: "BlueSkyFlier" Just before I close the cupboard door ... >From postings earlier in this thread it appears that some may be under the impression that opening up the throttle when using less than top RPM will give immediate access to power. That is a dangerous notion not to be trifled with. Please be aware that once your RPM has dropped - there is no guarantee that you will be able to regain RPM (i.e. power). Propeller loading and remaining available power alone will determine if rpm will increase again or not. For example, in the above diagram for 55 degree turn at 3500 feet the full throttle power at 3000 feet (for 125 hp engine) is shown as the lowermost diagonal rising line between 70 and 132 knots on the chart. Once the RPM has dropped below 2000 and the speed below 100 kt the load on the propeller will not allow it to speed up again even if you push the throttle to the wall - unless you can sacrifice altitude to reduce the load on the propeller. The true (hidden) meaning of the 'full throttle' power curve lies therein that - despite full throttle - you can not access all the power your engine can produce at that altitude unless your propeller loading is such that it allows rpm to increase. And if you increase the prop load by trying to make the plane go higher you lose even more power. You all know the scenario ... That is why it is best to avoid these areas where the 'full throttle' power dips below the power required to sustain level flight. Fair winds ... - Alfred -------- _________________________________________ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=333998#333998 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kis-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/KIS-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kis-list Browse Digests http://www.matronics.com/digest/kis-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.