---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Tue 09/22/09: 39 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:12 AM - Re: Crash (pj.ladd) 2. 02:43 AM - Re: An Older but Good Basic GPS (no aviation data base) (pj.ladd) 3. 04:12 AM - Re: crash (william sullivan) 4. 04:12 AM - Re: Crash (Richard Girard) 5. 04:24 AM - Re: An Older but Good Basic GPS (no aviation data base) (Richard Girard) 6. 04:39 AM - Re: Re: Cross wind capability of the Mk IIIC (Richard Girard) 7. 05:23 AM - Re: Cross wind capability of the Mk IIIC (Thom Riddle) 8. 06:43 AM - Re: An Older but Good Basic GPS (no aviation data base) (russ kinne) 9. 06:52 AM - Re: Re: Cross wind capability of the Mk IIIC (Richard Girard) 10. 07:11 AM - Re: Cross wind capability of the Mk IIIC (Thom Riddle) 11. 07:50 AM - Re: Re: Cross wind capability of the Mk IIIC (John Hauck) 12. 08:06 AM - Re: Re: Cross wind capability of the Mk IIIC (John Hauck) 13. 08:43 AM - Re: Fuel tank for FFFuel tank for FF (Dave Kulp) 14. 09:15 AM - Re: Crash (Jim Kmet) 15. 09:41 AM - Re: Cross wind capability of the Mk IIIC (JetPilot) 16. 09:44 AM - Re: Cross wind capability of the Mk IIIC (Thom Riddle) 17. 09:52 AM - Re: Cross wind capability of the Mk IIIC (JetPilot) 18. 10:41 AM - Re: Re: Cross wind capability of the Mk IIIC (possums) 19. 10:41 AM - Re: gyros (russ kinne) 20. 11:00 AM - Re: Cross wind capability of the Mk IIIC (JetPilot) 21. 11:21 AM - Re: gyros (JetPilot) 22. 11:24 AM - Re: Re: gyros (Robert Laird) 23. 11:38 AM - Re: Re: Cross wind capability of the Mk IIIC (Richard Girard) 24. 11:39 AM - Re: Re: Cross wind capability of the Mk IIIC (Richard Girard) 25. 11:46 AM - Re: Re: Cross wind capability of the Mk IIIC (Richard Girard) 26. 11:57 AM - Re: Re: Cross wind capability of the Mk IIIC (possums) 27. 12:11 PM - Re: Cross wind capability of the Mk IIIC (Thom Riddle) 28. 01:56 PM - Re: Crash (Kirby, Dennis CTR USAF AFMC MDA/AL) 29. 01:58 PM - Re: Re: gyros (russ kinne) 30. 02:25 PM - Re: Re: Cross wind capability of the Mk IIIC (zeprep251@aol.com) 31. 02:25 PM - Re: Re: Cross wind capability of the Mk IIIC (Richard Girard) 32. 03:44 PM - Re: Re: Cross wind capability of the Mk IIIC (John Hauck) 33. 03:44 PM - Re: Re: gyros (John Hauck) 34. 03:46 PM - Re: Re: Cross wind capability of the Mk IIIC (John Hauck) 35. 03:56 PM - Re: Re: gyros (John Hauck) 36. 05:38 PM - Re: Cross wind capability of the Mk IIIC (Thom Riddle) 37. 06:13 PM - Re: Re: Cross wind capability of the Mk IIIC (Richard Girard) 38. 07:58 PM - Re: Re: Cross wind capability of the Mk IIIC (possums) 39. 08:54 PM - Re: Cross wind capability of the Mk IIIC (Richard Pike) ________________________________ Message 1 _____________________________________ Time: 02:12:16 AM PST US From: "pj.ladd" Subject: Re: Kolb-List: Crash First Selectman Nicholas Mulane,>> This from the crash report. What is a First Selectman please? Pat ________________________________ Message 2 _____________________________________ Time: 02:43:46 AM PST US From: "pj.ladd" Subject: Re: Kolb-List: An Older but Good Basic GPS (no aviation data base) Did the GPS help or hinder the cat with mousing?. I just knew it! You will be happy to know that the mousing around the new frapping on the bitter end of the flying jib downhaul (Where the double bowline on a bight is secured just behind the binnacle) has cured the problem. Likewise the baggywrinkle. Thank you for your interest Cheers Pat ________________________________ Message 3 _____________________________________ Time: 04:12:07 AM PST US From: william sullivan Subject: Kolb-List: Re: crash - Pat- A Board of Selectman is a form of government used in some small to wns in Connecticut and elsewhere.- Usually three people are elected to th e board, and the top vote getter is the First Selectman.- Kind of like a town mayor. - do not archive ------------------------- ------------------- Bill Sullivan ------------------------- ------------------- Windsor Locks, Ct . (Has selectmen) ------------------------- ------------------- FS 447 ________________________________ Message 4 _____________________________________ Time: 04:12:46 AM PST US Subject: Re: Kolb-List: Crash From: Richard Girard Local politician, like a county councilor. Rick Girard do not archive On Tue, Sep 22, 2009 at 4:11 AM, pj.ladd wrote: > > First Selectman Nicholas Mulane,>> > > This from the crash report. What is a First Selectman please? > > Pat > > ________________________________ Message 5 _____________________________________ Time: 04:24:08 AM PST US Subject: Re: Kolb-List: An Older but Good Basic GPS (no aviation data base) From: Richard Girard Baggywrinkle - N. ME, usually seen on the large ladies of Walmart or in the mirror, usually under the eyes, after a night of tapping the admiral. Rick Girard do not archive On Tue, Sep 22, 2009 at 4:43 AM, pj.ladd wrote: > Did the GPS help or hinder the cat with mousing?. > > I just knew it! > > You will be happy to know that the mousing around the new frapping on the > bitter end of the flying jib downhaul (Where the double bowline on a bight > is secured just behind the binnacle) has cured the problem. Likewise the > baggywrinkle. > > Thank you for your interest > > Cheers > > Pat > > * > > * > > ________________________________ Message 6 _____________________________________ Time: 04:39:29 AM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: Richard Girard Thom, My thinking was that when the engine is cut to idle on approach the prop rpm is increased by the apparent wind making, in effect, a 66" diameter drag chute right in front of the rudder. Combine that with down elevator flying sideways and very little of the vertical stabilizer and rudder is "visible" to the apparent wind. I admit I may be over thinking the problem. :-) Rick do not archive On Mon, Sep 21, 2009 at 11:55 AM, Thom Riddle wrote: > > I'm having a hard time visualizing the rudder on a pusher getting blanked > out by any sort of slip. > > -------- > Thom Riddle > Buffalo, NY > Kolb Slingshot SS-021 > Jabiru 2200A #1574 > Tennessee Prop 64x34 > > A complex system that works is invariably found to have evolved from a > simple system that works. > - John Gaule > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=264151#264151 > > ________________________________ Message 7 _____________________________________ Time: 05:23:28 AM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "Thom Riddle" Rick, Lots of folks think that a prop driven by an engine at idle power produces more drag than thrust but I don't believe that is the case in most airplanes. Following is my rationale for that thinking. For a propeller that has a fixed pitch in flight, there is an rpm for every true airspeed that creates zero thrust and zero drag. In my airplane that I documented most thoroughly, my typical approach speed was 65 mph IAS which during typical ambient conditions equated to 61 mph TAS. For my engine and prop setup the zero thrust rpm for that airspeed was 2288 rpm. Any rpm greater than this zero thrust rpm at that airspeed would result in positive net thrust. IF at that airspeed you could get the engine rpm below that engine speed, then the result would be net drag from the prop. In my experience, the way most engine/props are typically set up, it is difficult or even impossible to get the engine rpm below the zero thrust speed at idle during normal glide approach. Your airplane may not be this way but all of mine have exhibited this characteristic. In the case of the airplane I'm referring to, my approach speed of 61 TAS and idle power resulted in about 2700 rpm or thereabouts. This means that the prop was producing a net positive thrust at idle power on approach. To confirm my theory, I have done engine off approaches (prop stopped) at my normal approach speed with the net result being a much steeper glide than with the engine at idle speed, i.e., the descent rate at the same airspeed was much greater than at idle power. Your airplane may be different but every one I've owned and tested behaved this way. If you know the pitch setting in inches for your prop, prop speed reduction ratio, and the TAS of your idle power approach, you can calculate the zero thrust rpm. If your engine is turning higher than this zero thrust speed under those conditions, your prop is producing a net positive thrust. If it is turning less than that zero thrust rpm, then your prop is producing a net drag force. The further away from this zero thrust rpm your engine is turning, the greater the magnitude of the net thrust or net drag. If you need help calculating this for your airplane let me know and I'll be glad to help you figure it out. -------- Thom Riddle Buffalo, NY Kolb Slingshot SS-021 Jabiru 2200A #1574 Tennessee Prop 64x34 A complex system that works is invariably found to have evolved from a simple system that works. - John Gaule Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264288#264288 ________________________________ Message 8 _____________________________________ Time: 06:43:21 AM PST US From: russ kinne Subject: Re: Kolb-List: An Older but Good Basic GPS (no aviation data base) Pat No tumblehome or deadrise involved? No scuppers?? Russ do not archive On Sep 22, 2009, at 5:43 AM, pj.ladd wrote: > Did the GPS help or hinder the cat with mousing?. > > I just knew it! > > You will be happy to know that the mousing around the new frapping > on the bitter end of the flying jib downhaul (Where the double > bowline on a bight is secured just behind the binnacle) has cured > the problem. Likewise the baggywrinkle. > > Thank you for your interest > > Cheers > > Pat > > ________________________________ Message 9 _____________________________________ Time: 06:52:34 AM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: Richard Girard Thom, On the other hand, my 582 idles at 1800 rpm (450 prop rpm) when all warmed up. Depending on speed the lowest rpm I see on approach is 2200 (550) to 2400 (600). That extra energy has to come from someplace and the only answer is the apparent wind flowing by the prop. I can tell the difference in sink speed if I open the throttle enough to relieve that loading without increasing rpm. When I had that gawd awful Rice King clutch in the gear box I could really see the difference as then the prop had no engine assistance and glide was of space shuttle variety. Again, power was extracted from the apparent wind.The question is, does that drag block or inhibit airflow and shadow the rudder? I'm inclined to think it does. Be comparison with the Mk III, I've landed a 150 in direct crosswinds of 30 mph and still had rudder available to maintain heading on the runway centerline. In 1/3 that wind (on average judging by the windsock) the Mk III rudder was mostly against the stop if I cut to idle power. Rick Girard do not archive On Tue, Sep 22, 2009 at 7:23 AM, Thom Riddle wrote: > > Rick, > > Lots of folks think that a prop driven by an engine at idle power produces > more drag than thrust but I don't believe that is the case in most > airplanes. Following is my rationale for that thinking. > > For a propeller that has a fixed pitch in flight, there is an rpm for every > true airspeed that creates zero thrust and zero drag. In my airplane that I > documented most thoroughly, my typical approach speed was 65 mph IAS which > during typical ambient conditions equated to 61 mph TAS. For my engine and > prop setup the zero thrust rpm for that airspeed was 2288 rpm. Any rpm > greater than this zero thrust rpm at that airspeed would result in positive > net thrust. IF at that airspeed you could get the engine rpm below that > engine speed, then the result would be net drag from the prop. In my > experience, the way most engine/props are typically set up, it is difficult > or even impossible to get the engine rpm below the zero thrust speed at idle > during normal glide approach. Your airplane may not be this way but all of > mine have exhibited this characteristic. In the case of the airplane I'm > referring to, my approach speed of 61 TAS and idle power resulted in about > 2700 rpm or thereabouts! > . This means that the prop was producing a net positive thrust at idle > power on approach. To confirm my theory, I have done engine off approaches > (prop stopped) at my normal approach speed with the net result being a much > steeper glide than with the engine at idle speed, i.e., the descent rate at > the same airspeed was much greater than at idle power. Your airplane may be > different but every one I've owned and tested behaved this way. > > If you know the pitch setting in inches for your prop, prop speed reduction > ratio, and the TAS of your idle power approach, you can calculate the zero > thrust rpm. If your engine is turning higher than this zero thrust speed > under those conditions, your prop is producing a net positive thrust. If it > is turning less than that zero thrust rpm, then your prop is producing a net > drag force. The further away from this zero thrust rpm your engine is > turning, the greater the magnitude of the net thrust or net drag. > > If you need help calculating this for your airplane let me know and I'll be > glad to help you figure it out. > > -------- > Thom Riddle > Buffalo, NY > Kolb Slingshot SS-021 > Jabiru 2200A #1574 > Tennessee Prop 64x34 > > A complex system that works is invariably found to have evolved from a > simple system that works. > - John Gaule > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=264288#264288 > > ________________________________ Message 10 ____________________________________ Time: 07:11:15 AM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "Thom Riddle" Rick, Perhaps but... If the prop is turning at a rate that gives it a positive angle of attack with the relative wind, a necessity by definition if more than the zero thrust speed, then the prop is not being "pushed" by the prevailing wind, rather it is producing thrust. The reason that the idle speed in glide is higher than the static idle speed is that the angle of attack is much less when moving forward than it is when stationary, but it is still a positive angle of attack if the rpm is greater than the zero thrust rpm for a given airspeed. That is my intuitive understanding of the situation. It could be wrong but I don't understand how if it is. Any aerodynamicists among us who would like to clear this up? -------- Thom Riddle Buffalo, NY Kolb Slingshot SS-021 Jabiru 2200A #1574 Tennessee Prop 64x34 A complex system that works is invariably found to have evolved from a simple system that works. - John Gaule Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264299#264299 ________________________________ Message 11 ____________________________________ Time: 07:50:44 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC Must have been a humongous rudder on that 150. I am not 150 qualifed, but I bet the book says the max cross wind component is about 15 mph at 90 degrees. john h mkIII Rock House, Oregon Be comparison with the Mk III, I've landed a 150 in direct crosswinds of 30 mph and still had rudder available to maintain heading on the runway centerline. In 1/3 that wind (on average judging by the windsock) the Mk III rudder was mostly against the stop if I cut to idle power. Rick Girard ________________________________ Message 12 ____________________________________ Time: 08:06:53 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC > Any aerodynamicists among us who would like to clear this up? > > -------- > Thom Riddle I discovered the difference between engine idle power glide and dead stick glide by experimenting. Dead stick significantly increases glide in a Kolb. Don't know about other airplanes because I never experiemented with them. I have always felt folks needed to learn how to fly their Kolbs at idle power, and also practice dead stick landings. The reason, the glide is so much better dead stick, one could get into trouble selecting a forced landing area and over flying it. Can't prove it on paper, nor do I have any desire to, but the prop disc becomes a large round disc when reduced to engine idle power. An example of this is a helicopter in autorotation. If the main rotor blades did not slow the aircraft down by increasing drag, it would fall out of the sky. A gyrocopter is continuously autorotating because it is a big pin wheel. Probably why it takes so much power to fly. My own opinion. Worth what you paid for it. Take care, john h mkIII Rock House, Oregon ________________________________ Message 13 ____________________________________ Time: 08:43:15 AM PST US From: Dave Kulp Subject: Re: Kolb-List: Fuel tank for FFFuel tank for FF Actually, my FF has an enclosure built for a 10 gallon tank, but had a 5 gal. plus foam filler when I bought it. So... a few more 18 minute units could be helpful from time to time. More helpful than matrimony, Beauford. Although I miss the scent of a woman in my house, the scent of my dog is pretty nice... and he waits so patiently in my pickup while I'm flying around!! Dave Kulp FireFly 11DMK ________________________________ Message 14 ____________________________________ Time: 09:15:53 AM PST US From: "Jim Kmet" Subject: Re: Kolb-List: Crash Message to me from Dan Patrick about mishap: Hi Jim I just got in from the field preping to get the plane out. Am fine just a little back and neck stiff. Y ou know the old saying "low and slow" on final 20o flaps rt.hand for flaps and stick to lt. hand, I went to 40obefore the tree line, ?little low, flaps to 20o switching hands I push flap handle up and by accident other hand put slight forward pressure on the stick. I added throttle and back on the stick. Landing gear caught branches and went in. Poor judgement being that low. All is O K,will rebuild. Thanks for the inquiry ----- Original Message ----- From: "John Hauck" Sent: Monday, September 21, 2009 2:12 PM Subject: Kolb-List: Crash > > Gang: > > Is this one of our guys? > > john h > mkIII > Rock House, Oregon > > > IDENTIFICATION > Regis#: 208NS Make/Model: EXP Description: KOLB MARK III > EXTRA > Date: 09/20/2009 Time: 1434 > > Event Type: Incident Highest Injury: None Mid Air: N Missing: N > Damage: Unknown > > LOCATION > City: NORTH STONINGTON State: CT Country: US > > DESCRIPTION > AIRCRAFT CRASHED IN A WOODED AREA, NORTH STONINGTON, CT > > INJURY DATA Total Fatal: 0 > # Crew: 1 Fat: 0 Ser: 0 Min: 0 > Unk: 1 > > > ________________________________ Message 15 ____________________________________ Time: 09:41:00 AM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "JetPilot" In almost all airplanes, stopping the prop completely reduces drag and increases glide. A windmilling prop is much worse than a stopped one if you are trying to glide. As John H says, a helicopter would fall out of the air if this were not true. A gyrocopter just has a big windmilling prop on the top of it, no power to it at all, and if it were to ever stop in the air the gyrocopter would fall like a rock. John H, Have you ever tried Dead stick gliding and landings in your MK III ??? My minimum descent rate in my Kolb MK III Xtra is 500 FPM at 55 MPH and 1800 RPM - Minimum Idle power for my Rotax 912-S. When I shut down the engine and stop the prop completely, my descent rate increases to 900 Feet per minute, it is much worse [Evil or Very Mad] This was the total opposite of what I was expecting, but I have done this a number of times and this is just the way it is in my Kolb. It does not make any sense and goes against theory, but I have tried varying the airspeeds, and tested this quite a number of times with always the same result, when I stop the prop instead of idle at 1800 RPM, my glide is reduced by a huge amount. Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264335#264335 ________________________________ Message 16 ____________________________________ Time: 09:44:24 AM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "Thom Riddle" For more on zero thrust rpm see the following: http://cafefoundation.org/v2/aboutcafe_orderfromchaos.php -------- Thom Riddle Buffalo, NY Kolb Slingshot SS-021 Jabiru 2200A #1574 Tennessee Prop 64x34 A complex system that works is invariably found to have evolved from a simple system that works. - John Gaule Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264336#264336 ________________________________ Message 17 ____________________________________ Time: 09:52:23 AM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "JetPilot" My best guess for the situation above is that my Rotax 912-S must be producing a significant amount of thrust even at 1800 RPM idle power... Rotax prohibits idling this engine below 1800 RPM, so I don't have any figures below that RPM where the prop probably goes from still producing some thrust to windmilling and creating drag instead of thrust. Just a guess, that this is the only thing that makes sense. 1800 RPM = Minimum Descent rate at 55 MPH 500 Feet Per Minute Prop Stopped = Minimum Descent rate at 55 MPH 900 Feet Per Minute The did this test many times and at different airspeeds, the test results don't lie.. Something has to be causing it. Those thinking that they may have the same glide with the engine stopped that they have at idle power should really try this one day, they might be in for a big surprise, I sure was !!! PS, start High up and make sure you have a HUGE runway, and aim for the middle, because you might end up much shorter than you expect. Some Kolbs actually glide better with the prop stopped, the reports are out there, which is why I suggest trying it under very controlled conditions, because it is better to know what to expect rather than be surprised if your engine ever does completely quit. Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264338#264338 ________________________________ Message 18 ____________________________________ Time: 10:41:38 AM PST US From: possums Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC At 12:52 PM 9/22/2009, you wrote: > >My best guess for the situation above is that my Rotax 912-S must be >producing a significant amount of thrust even at 1800 RPM idle >power... Rotax prohibits idling this engine below 1800 RPM, so I >don't have any figures below that RPM where the prop probably goes >from still producing some thrust to windmilling and creating drag >instead of thrust. Just a guess, that this is the only thing that >makes sense. > >1800 RPM = Minimum Descent rate at 55 MPH 500 Feet Per Minute >Prop Stopped = Minimum Descent rate at 55 MPH 900 Feet Per Minute Does the prop windmill on a 912 engine? It won't on a 503 with no clutch. ________________________________ Message 19 ____________________________________ Time: 10:41:38 AM PST US From: russ kinne Subject: Kolb-List: Re: gyros BTW, gyrocopters do NOT "fall like a rock" without power. They autorotate down to a smooth landing. Ken Brock used to cut power, prop stopped, at about 500' & autorotate down to a smooth, very soft landing. Nothing bent, he waved & walked away from it. Repeatedly! -- part of his airshow routine. (In a Bensen gyrocopter) Helicopters can of course autorotate to a fairly soft landing if they have enough altitude to get everything done in time. "Fall like a rock"? I don't think so. Russ K do not archive On Sep 22, 2009, at 12:39 PM, JetPilot wrote: > > In almost all airplanes, stopping the prop completely reduces drag > and increases glide. A windmilling prop is much worse than a > stopped one if you are trying to glide. As John H says, a > helicopter would fall out of the air if this were not true. A > gyrocopter just has a big windmilling prop on the top of it, no > power to it at all, and if it were to ever stop in the air the > gyrocopter would fall like a rock. ________________________________ Message 20 ____________________________________ Time: 11:00:18 AM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "JetPilot" Possums wrote: > > Does the prop windmill on a 912 engine? It won't on a 503 with no clutch. No, the prop comes to a very abrupt and sudden stop when the engine is shut down on a 912-S. I think even if I dived to over 100 MPH and the prop would still not windmill. I remember some engine off videos you posted a long time back Possums, did your glide increase or decrease with the engine off ? Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264348#264348 ________________________________ Message 21 ____________________________________ Time: 11:21:52 AM PST US Subject: Kolb-List: Re: gyros From: "JetPilot" Russ, In your jubilation and glee when you thought you had found that I made a mistake, you were in such a hurry to start a new thread and point out that I had made an a mistake that you failed to read what I posted and understand it. I said if the BIG windmilling prop on TOP of the gyrocopter ever stopped - Meaning the ROTOR, the gyrocopter would fall like a rock, which is very true. You sure are desperate to find something wrong with something I have posted, it took you only a couple minutes for you to start a new thread on where you thought I made a mistake. Funny, with all the incorrect and bad information posted on this forum, you have only started a new thread on the subject when you thought I said something wrong... Get over your vindictiveness and need to get revenge , its pathetic. Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264350#264350 ________________________________ Message 22 ____________________________________ Time: 11:24:04 AM PST US Subject: Re: Kolb-List: Re: gyros From: Robert Laird Correct, Russ! EVERY landing I do in my gyro is softer than a kittens paw, and EVERY one is done with the engine at idle. I've done them from as high as 1500 feet AGL (no reason it couldn't be higher), and as low as 30 feet... chop the power, lean into it slowly, maintaining best-glide speed, then flare. Couldn't be simpler. My roll-out is usually between 10 and 20 feet. But, to be fair, I think he was speaking theoretically. Yes, if my rotor was suddenly frozen by a futuristic stasis ray gun, the gyro would drop like a rock. But, that would be like saying, if a fixed wing aircraft has its wing suddenly vaporized, it would fall like a rock. Yep. The wing, to rotor, are providing the lift for the craft... without that lift, they are both toast. -- Robert (flying a Gyrobee as well as a Kolb) On Tue, Sep 22, 2009 at 12:36 PM, russ kinne wrote: > > BTW, gyrocopters do NOT "fall like a rock" without power. They autorotate > down to a smooth landing. > Ken Brock used to cut power, prop stopped, at about 500' & autorotate down > to a smooth, very soft landing. Nothing bent, he waved & walked away from > it. Repeatedly! -- part of his airshow routine. (In a Bensen gyrocopter) > Helicopters can of course autorotate to a fairly soft landing if they have > enough altitude to get everything done in time. > "Fall like a rock"? I don't think so. > Russ K > do not archive > > > On Sep 22, 2009, at 12:39 PM, JetPilot wrote: > >> >> In almost all airplanes, stopping the prop completely reduces drag and >> increases glide. A windmilling prop is much worse than a stopped one if >> you are trying to glide. As John H says, a helicopter would fall out of >> the air if this were not true. A gyrocopter just has a big windmilling prop >> on the top of it, no power to it at all, and if it were to ever stop in the >> air the gyrocopter would fall like a rock. > > ________________________________ Message 23 ____________________________________ Time: 11:38:54 AM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: Richard Girard Thom, If your conjecture was true windmills would be increasing the rate of the earth's rotation. :-) Rick Girard do not archive On Tue, Sep 22, 2009 at 1:29 PM, Richard Girard wrote: > John, The book says demonstrated cross wind capability, not maximum. I had > a girl friend who lived at the beach. I suppose I could call it a humongous > rudder but I'm more modest than that. :-) > Rick > > > On Tue, Sep 22, 2009 at 9:50 AM, John Hauck wrote: > >> Must have been a humongous rudder on that 150. >> >> I am not 150 qualifed, but I bet the book says the max cross wind >> component is about 15 mph at 90 degrees. >> >> john h >> mkIII >> Rock House, Oregon >> >> >> >> >> Be comparison with the Mk III, I've landed a 150 in direct crosswinds of >> 30 mph and still had rudder available to maintain heading on the runway >> centerline. In 1/3 that wind (on average judging by the windsock) the Mk III >> rudder was mostly against the stop if I cut to idle power. >> >> Rick Girard >> >> >> * >> >> * >> >> > ________________________________ Message 24 ____________________________________ Time: 11:39:38 AM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: Richard Girard John, The book says demonstrated cross wind capability, not maximum. I had a girl friend who lived at the beach. I suppose I could call it a humongous rudder but I'm more modest than that. :-) Rick On Tue, Sep 22, 2009 at 9:50 AM, John Hauck wrote: > Must have been a humongous rudder on that 150. > > I am not 150 qualifed, but I bet the book says the max cross wind component > is about 15 mph at 90 degrees. > > john h > mkIII > Rock House, Oregon > > > Be comparison with the Mk III, I've landed a 150 in direct crosswinds of > 30 mph and still had rudder available to maintain heading on the runway > centerline. In 1/3 that wind (on average judging by the windsock) the Mk III > rudder was mostly against the stop if I cut to idle power. > > Rick Girard > > > * > > * > > ________________________________ Message 25 ____________________________________ Time: 11:46:45 AM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: Richard Girard They don't go into the detail of how zero thrust is found in this article, although they did in another. Sorry, I don't have the reference, but the method was relatively simple. Measure the crankshaft's end play with a force gauge. When the prop is being pushed backward it's producing drag, when it's pulled forward it's producing thrust. In the middle it's in zero thrust mode. Rick Girard do not archive On Tue, Sep 22, 2009 at 11:43 AM, Thom Riddle wrote: > > For more on zero thrust rpm see the following: > > http://cafefoundation.org/v2/aboutcafe_orderfromchaos.php > > -------- > Thom Riddle > Buffalo, NY > Kolb Slingshot SS-021 > Jabiru 2200A #1574 > Tennessee Prop 64x34 > > A complex system that works is invariably found to have evolved from a > simple system that works. > - John Gaule > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=264336#264336 > > ________________________________ Message 26 ____________________________________ Time: 11:57:04 AM PST US From: possums Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC At 01:59 PM 9/22/2009, you wrote: > > >Possums wrote: > > > > Does the prop windmill on a 912 engine? It won't on a 503 with no clutch. > > >No, the prop comes to a very abrupt and sudden stop when the engine >is shut down on a 912-S. I think even if I dived to over 100 MPH >and the prop would still not windmill. > >I remember some engine off videos you posted a long time back >Possums, did your glide increase or decrease with the engine off ? > >Mike > >-------- >"NO FEAR" - If you have no fear you did not go as fast as >you could have !!! Mine glides better with the prop stopped. About 500 fpm? drop on a nice calm day. ________________________________ Message 27 ____________________________________ Time: 12:11:45 PM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "Thom Riddle" [size=12]Rick, To help clear up my understanding of your working theory please answer the following questions: 1- When flying at cruise power or higher, is your prop producing a net positive thrust force or net drag force (negative thrust)? 2- Would the glide performance of your airplane with power off and prop stopped be better or worse than if the prop were not even on the engine? In other words, would the total drag of the airplane gliding at a given speed be more or less with a stopped prop or no prop at all on the airplane? Thanks for your help. -------- Thom Riddle Buffalo, NY Kolb Slingshot SS-021 Jabiru 2200A #1574 Tennessee Prop 64x34 A complex system that works is invariably found to have evolved from a simple system that works. - John Gaule Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264359#264359 ________________________________ Message 28 ____________________________________ Time: 01:56:26 PM PST US Subject: Re: Kolb-List: Crash From: "Kirby, Dennis CTR USAF AFMC MDA/AL" Jim Kmet wrote: << Dan Patrick. Newly built MK-3X Was not his first flight. Low time Light sport pilot. I know no more details, but will try to find out. >> This XTra was powered by an HKS-700. Not trying to speculate here, but I wonder if being underpowered could have contributed to Dan's unfortunate accident. Isn't 60 hp somewhat marginal power for a Mark-IIIX? Dennis Kirby New Mexico ________________________________ Message 29 ____________________________________ Time: 01:58:19 PM PST US From: russ kinne Subject: Re: Kolb-List: Re: gyros Mike I apologise for not understanding your post correctly; but I'm hardly 'vindictive' or 'desperate', I don't need 'revenge' and I hope I'm not 'pathetic' Please accept my sincere apology. Russ K On Sep 22, 2009, at 2:21 PM, JetPilot wrote: > > Russ, > > In your jubilation and glee when you thought you had found that I > made a mistake, you were in such a hurry to start a new thread and > point out that I had made an a mistake that you failed to read what > I posted and understand it. I said if the BIG windmilling prop on > TOP of the gyrocopter ever stopped - Meaning the ROTOR, the > gyrocopter would fall like a rock, which is very true. > > You sure are desperate to find something wrong with something I > have posted, it took you only a couple minutes for you to start a > new thread on where you thought I made a mistake. Funny, with > all the incorrect and bad information posted on this forum, you > have only started a new thread on the subject when you thought I > said something wrong... Get over your vindictiveness and need to > get revenge , its pathetic. > > Mike > > -------- > "NO FEAR" - If you have no fear you did not go as fast > as you could have !!! > > Kolb MK-III Xtra, 912-S > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=264350#264350 > > ________________________________ Message 30 ____________________________________ Time: 02:25:16 PM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: zeprep251@aol.com Hey guys, ?My 503 idled at 1780 rpm,but it would always be turning 2200 or better on landing with the nose down and it really helped keep the speed down,you could feel it.3 blade IVO. ?G.Aman -----Original Message----- From: possums Sent: Tue, Sep 22, 2009 2:58 pm Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC ? At 01:59 PM 9/22/2009, you wrote:? >? >? >Possums wrote:? > >? > > Does the prop windmill on a 912 engine? It won't on a 503 with no clutch.? >? >? >No, the prop comes to a very abrupt and sudden stop when the engine >is shut down on a 912-S. I think even if I dived to over 100 MPH >and the prop would still not windmill.? >? >I remember some engine off videos you posted a long time back >Possums, did your glide increase or decrease with the engine off ?? >? >Mike? >? >--------? >"NO FEAR" - If you have no fear you did not go as fast as >you could have !!!? ? Mine glides better with the prop stopped. About 500 fpm? drop on a nice calm day.? ? ? ? ? ________________________________ Message 31 ____________________________________ Time: 02:25:41 PM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: Richard Girard 1. Thrust, just like all the books say. No thrust, no level flight. The prop produces net thrust, the airframe produces net drag. In unaccelerated flight, they balance. But those are conditions beyond your question, you didn't specify level flight so the answer to it is, it depends. I cruise at 5200 rpm. In level flight that gets me about 65 mph IAS. I change nothing but the stick position by pushing it forward and speed goes up slightly at first, but so does rpm as the prop unloads the engine. I keep pushing forward but now the prop is loading the engine in reverse which is preventing the prop from turning any faster and it is now producing drag. Speed will rise IF the airplanes kinetic energy overcomes that greater net drag of airframe and wind driven prop. When it doesn't acceleration stops and things are again in balance.2. My airplane has a 582 and a 4:00 to 1 gearbox. The only way the prop can be stopped in flight is if the engine seized. :-) However, if the prop were stopped it would be about the same as a 66" long piece of 2 X 4 stuck flat side against the wind and produce about the same amount of drag. More drag, same lift, worse lift to drag ratio. Take away the stopped prop, less drag, same lift, better lift to drag ratio. Rick Girard do not archive On Tue, Sep 22, 2009 at 2:11 PM, Thom Riddle wrote: > > [size=12]Rick, > > To help clear up my understanding of your working theory please answer the > following questions: > > 1- When flying at cruise power or higher, is your prop producing a net > positive thrust force or net drag force (negative thrust)? > > 2- Would the glide performance of your airplane with power off and prop > stopped be better or worse than if the prop were not even on the engine? In > other words, would the total drag of the airplane gliding at a given speed > be more or less with a stopped prop or no prop at all on the airplane? > > Thanks for your help. > > -------- > Thom Riddle > Buffalo, NY > Kolb Slingshot SS-021 > Jabiru 2200A #1574 > Tennessee Prop 64x34 > > A complex system that works is invariably found to have evolved from a > simple system that works. > - John Gaule > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=264359#264359 > > ________________________________ Message 32 ____________________________________ Time: 03:44:58 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC > Have you ever tried Dead stick gliding and landings in your MK III ??? My minimum descent rate in my Kolb MK III Xtra is 500 FPM at 55 MPH and 1800 RPM - Minimum Idle power for my Rotax 912-S. When I shut down the engine and stop the prop completely, my descent rate increases to 900 Feet per minute, it is much worse [Evil or Very Mad] This was the total opposite of what I was expecting, but I have done this a number of times and this is just the way it is in my Kolb. It does not make any sense and goes against theory, but I have tried varying the airspeeds, and tested this quite a number of times with always the same result, when I stop the prop instead of idle at 1800 RPM, my glide is reduced by a huge amount. > > Mike Mike B/Gang: Yes, I have done many dead stick landings in my mkIII. I don't remember the numbers, but I do remember the glide being much better with a dead stick. Minimum rpm at closed throttle on my 912ULS while flying is about 2200 rpm. On the ground I have my idle set for about 1700 rpm. Sometimes Kolbs do some screwy things that "experts" with other airplanes can not explain. This increased rate of decent while dead stick may be one of them. When I get home and start flying again I'll check it out and see what I come up with. john h mkIII Rock House, Oregon ________________________________ Message 33 ____________________________________ Time: 03:44:58 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: gyros > BTW, gyrocopters do NOT "fall like a rock" without power. They > autorotate down to a smooth landing. > Helicopters can of course autorotate to a fairly soft landing if > they have enough altitude to get everything done in time. > "Fall like a rock"? I don't think so. > Russ K Russ K/Gang: Gyros are right behind rocks when they lose power. They are in contant autorotation when flying, with or without a source of thrust. Helicopters feel like they are falling out of the sky in autorotation, especially a 180 degree autorotation. Even normal approaches to land a steep compared to fixed wing aircraft. Guess that is one reason I have always been comfortable flying Kolbs. Helicopters used to have a dead man's curve, when I was flying them many years ago, published in the operational manual. This was the airspeed/altitude that an autorotation would probably not be sucessful. john h mkIII Rock House, Oregon ________________________________ Message 34 ____________________________________ Time: 03:46:26 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC > Does the prop windmill on a 912 engine? It won't on a 503 with no clutch. Possum/Gang: Not from dead stick, but my 912ULS does increase from around 1600-1700 rpm to about 2200 rpm during gliding decents. >From dead stick, the prop stays stuck. ;-) john h mkIII Rock House, Oregon ________________________________ Message 35 ____________________________________ Time: 03:56:15 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: gyros > Correct, Russ! EVERY landing I do in my gyro is softer than a kittens > paw, and EVERY one is done with the engine at idle. I've done them > from as high as 1500 feet AGL (no reason it couldn't be higher), and > as low as 30 feet... chop the power, lean into it slowly, maintaining > best-glide speed, then flare. Couldn't be simpler. My roll-out is > usually between 10 and 20 feet. > > -- Robert (flying a Gyrobee as well as a Kolb) Robert L/Gang: Of course your landing is always done with forward airspeed when the engine is at idle. If not, it loses rotor rpm quickly. Also, the gyro is never out of autorotation from take off to landing, with out without power. Helicopters do quite well in autorotation, especially with forward airspeed. They'll also autorotate sideways and aft, but will probably be hard on the skids that way. Hovering autorotations are a piece of cake in Army helicopters in ground effect, but sucessful higher hovering autorotations depend on load and main rotor enertia. john h mkIII Rock House, Oregon DO NOT ARCHIVE ________________________________ Message 36 ____________________________________ Time: 05:38:48 PM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "Thom Riddle" Rick, If the prop at cruise power is producing positive thrust and the prop stopped is producing negative thrust (drag), then at some point between cruise rpm and zero rpm the net thrust goes from positive to negative. At that rpm for that airspeed, the net thrust is exactly zero. With the rpm above that (being driving by a running engine), there is some positive net thrust. With the engine running at any rpm below that transition point from positive to negative the net result is drag all the way down to and including zero rpm. Maybe John H's MkIII has better glide with the engine and prop stopped than at idle power at the same airspeed but none of my airplanes have done that nor does Mike Bigelow's MkIIIX, according to his recent report. During my next flight I will note the descent speeds at my normal approach airspeed with engine at idle and with the engine stopped. I'll be mightily surprised if the descent rate with the prop stopped is lower than when at idle power. But I'm open to being surprised. Nothing like empirical evidence to prove one right or wrong. In either case, I agree with John H. that it is a good idea to get familiar with your airplanes' glide characteristics with the engine actullay stopped. This is not something you want to learn when it is an actual emergency. -------- Thom Riddle Buffalo, NY Kolb Slingshot SS-021 Jabiru 2200A #1574 Tennessee Prop 64x34 A complex system that works is invariably found to have evolved from a simple system that works. - John Gaule Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264415#264415 ________________________________ Message 37 ____________________________________ Time: 06:13:02 PM PST US Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC From: Richard Girard Not that I would ever advocate not practicing anything a pilot thinks is useful in an emergency, but a far more useful skill IMHO is being able to instantly recognize what Langewiesche called "the point that does not move". If you can recognize that it won't matter what condition the airplane is in or the airspeed you're flying you'll make the field if it's possible at all. Rick Girard do not archive On Tue, Sep 22, 2009 at 7:38 PM, Thom Riddle wrote: > > Rick, > > If the prop at cruise power is producing positive thrust and the prop > stopped is producing negative thrust (drag), then at some point between > cruise rpm and zero rpm the net thrust goes from positive to negative. At > that rpm for that airspeed, the net thrust is exactly zero. With the rpm > above that (being driving by a running engine), there is some positive net > thrust. With the engine running at any rpm below that transition point from > positive to negative the net result is drag all the way down to and > including zero rpm. > > Maybe John H's MkIII has better glide with the engine and prop stopped than > at idle power at the same airspeed but none of my airplanes have done that > nor does Mike Bigelow's MkIIIX, according to his recent report. During my > next flight I will note the descent speeds at my normal approach airspeed > with engine at idle and with the engine stopped. I'll be mightily surprised > if the descent rate with the prop stopped is lower than when at idle power. > But I'm open to being surprised. Nothing like empirical evidence to prove > one right or wrong. > > In either case, I agree with John H. that it is a good idea to get familiar > with your airplanes' glide characteristics with the engine actullay stopped. > This is not something you want to learn when it is an actual emergency. > > -------- > Thom Riddle > Buffalo, NY > Kolb Slingshot SS-021 > Jabiru 2200A #1574 > Tennessee Prop 64x34 > > A complex system that works is invariably found to have evolved from a > simple system that works. > - John Gaule > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=264415#264415 > > ________________________________ Message 38 ____________________________________ Time: 07:58:19 PM PST US From: possums Subject: Re: Kolb-List: Re: Cross wind capability of the Mk IIIC At 03:11 PM 9/22/2009, you wrote: > >[size=12]Rick, > >To help clear up my understanding of your working theory please >answer the following questions: > >1- When flying at cruise power or higher, is your prop producing a >net positive thrust force or net drag force (negative thrust)? > >2- Would the glide performance of your airplane with power off and >prop stopped be better or worse than if the prop were not even on >the engine? In other words, would the total drag of the airplane >gliding at a given speed be more or less with a stopped prop or no >prop at all on the airplane? > >Thanks for your help. > >-------- >Thom Riddle I don't under stand how a stopped prop (you can consider the frontal area of the prop to be the total source of drag) would slow you down more than a spinning prop. Either It's pushing the plane forward producing thrust at whatever speed or at the other extreme, the whole swept area of the spinning prop is considered as a flat drag plate when it's windmilling. Or you have the magic touch and can spin the prop at the exact RPM to create no drag at all. It would bet better with no prop at all or a folding prop as seen on some self propelled gliders. The cleaner you plane is the more this might matter. I don't think it would make much difference in a Quicksilver. ________________________________ Message 39 ____________________________________ Time: 08:54:24 PM PST US Subject: Kolb-List: Re: Cross wind capability of the Mk IIIC From: "Richard Pike" [quote="Possums"]At 03:11 PM 9/22/2009, you wrote: > > [size=12]Rick, > > To help clear up my understanding of your working theory please answer the following questions: > > 1- When flying at cruise power or higher, is your prop producing a net positive thrust force or net drag force (negative thrust)? > > 2- Would the glide performance of your airplane with power off and prop stopped be better or worse than if the prop were not even on the engine? In other words, would the total drag of the airplane gliding at a given speed be more or less with a stopped prop or no prop at all on the airplane? > > Thanks for your help. > > -------- > Thom Riddle I don't under stand how a stopped prop (you can consider the frontal area of the prop to be the total source of drag) would slow you down more than a spinning prop. Either It's pushing the plane forward producing thrust at whatever speed or at the other extreme, the whole swept area of the spinning prop is considered as a flat drag plate when it's windmilling. Or you have the magic touch and can spin the prop at the exact RPM to create no drag at all. It would bet better with no prop at all or a folding prop as seen on some self propelled gliders. The cleaner you plane is the more this might matter. I don't think it would make much difference in a Quicksilver. > [b] ****************************************************** According to this web site, there is a negative thrust from a windmilling prop at some combination of windmilling rpm and glide speed. http://home.scarlet.be/comicstrip/Drag%20prop/Drag%20From%20Prop.htm Don't know if it's true or not, but interesting. Richard Pike MKIII N420P (420ldPoops) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264448#264448 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-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/kolb-list Browse Digests http://www.matronics.com/digest/kolb-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.