---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Mon 11/01/04: 20 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:24 AM - Matronics 2004 Email List Fund Raiser [PLEASE READ] (Matt Dralle) 2. 05:23 AM - Re: Considering to buy second hand Kolb MK3: Where to watch out (Thom Riddle) 3. 05:54 AM - prebuy check (Charles & Meredith Blackwell) 4. 06:50 AM - Ms. Dixie report (Paul Petty) 5. 07:36 AM - Re: best lift to drag speed. (boyd young) 6. 07:47 AM - Re: Considering to buy second hand Kolb MK3: Where to watch out for? (John Jung) 7. 07:52 AM - Re: Re: best lift to drag speed. (PATRICK LADD) 8. 08:08 AM - Re: Considering to buy second hand Kolb MK3: Where to watch out for? (PATRICK LADD) 9. 08:19 AM - Re: Ms. Dixie report (John Williamson) 10. 08:51 AM - Best climb... (Jeremy Casey) 11. 09:06 AM - Las Vegas (James, Ken) 12. 02:20 PM - Re: Re: best lift to drag speed. (John Hauck) 13. 04:06 PM - my Firestar's longest trip w/o leaving the ground! (Jon Croke) 14. 04:46 PM - Re: best lift to drag speed. (David Paule) 15. 05:03 PM - Re: my Firestar's longest trip w/o leaving the ground! (Larry Bourne) 16. 05:53 PM - Re: my Firestar's longest trip w/o leaving the (jerb) 17. 07:07 PM - Re: Best climb... (Larry Cottrell) 18. 07:11 PM - Re: Re: best lift to drag speed. (John Williamson) 19. 07:21 PM - Re: my Firestar's longest trip w/o leaving the ground! (tj brown) 20. 07:21 PM - Re: Best climb... (John Hauck) ________________________________ Message 1 _____________________________________ Time: 03:24:00 AM PST US From: Matt Dralle Subject: Kolb-List: Matronics 2004 Email List Fund Raiser [PLEASE READ] --> Kolb-List message posted by: Matt Dralle Dear Listers, Each November I hold a PBS-like Fund Raiser to support the continued operation and upgrade of the Email List servers at Matronics. The Lists sponsored here are supported solely though the direct contributions of its members each year during the Fund Raiser. As you have likely noticed, there is no commercial advertising on any of the Lists or on any of the List-related web sites such as the List Browser and List Search Engine. That doesn't mean they're free to operate, however. To run a first class, high-performance, highly-available service such as the Forums at Matronics, its take resources. These resources fall into the categories of financial and personnel. As far as "personnel" is concerned, its a one-man show and I perform all of the work required to operate and upgrade the Lists without being directly compensated for my work. But that's a labor of love. The financial resources required, on the other hand, are covered primarily though the generous contributions of the List members. Direct costs include, for example, a commercial-grade T1 line Internet connection dedicated primarily to serving the Lister Community. This T1 Internet connection provides a high-performance, dedicated connection to the Archive and Browsing Tools and assures the quickest, most reliable delivery of List messages. It seems like there's always an upgrade required and this year I've added an all new online backup system to automatically backup all of the Lists Archives as well as provide for complete system disaster recovery. This new system would enable me to restore the email and/or web server systems to 100% in only a couple of hours if one of them were to blow up. The number of messages processed by the Matronics Forums continues to increase as well. In the last 12 months, there have been over 70,000 unique messages posted across the various lists, amounting to well over 32 MILLION messages that have been redistributed to List members in that same period! The List web site also sees an equally high level of traffic with some 148,000 Archive searches performed last year and a staggering 13 million web site hits! During the month of November, I will be sending out a Fund Raiser reminder message a couple of times a week and I ask for your patience and understanding during this time. The Fund Raiser is the sole means of support for the Lists, and the existence and longevity of the Lists hinges directly its success. This year once again, Andy Gold of the Builder's Bookstore has provided a number of great incentive gifts during the Fund Raiser. Andy provides these items to me at a substantial discount and they have proven to be very popular among the Listers. Thank you Andy for your extraordinary generosity and support of the Lists again this year! Please visit Andy's web site, the Builder's Bookstore: http://www.buildersbooks.com If you use the Matronics Email Lists and enjoy the quick and easy access to one of the best resources on the Internet for Homebuilt and General aviation discussion forums, please make a Contribution today to support the continued operation. Remember, its *your* Contribution that keeps these Lists running. The Contribution web site is freshly updated with a list of all new incentive gifts! Transactions are SSL secured and you can make your Contribution using a credit card, Paypal, or a personal check. The Contribution web site can be found at: http://www.matronics.com/contribution Thank you for your support!! Matt Dralle Matronics Email List Administrator Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft do not archive ________________________________ Message 2 _____________________________________ Time: 05:23:55 AM PST US From: "Thom Riddle" Subject: Kolb-List: Re: Considering to buy second hand Kolb MK3: Where to watch out --> Kolb-List message posted by: "Thom Riddle" Pollus, Welcome to the Kolb world. I had an early FireStar but it has been sold and I have no first hand experience with the MkIII. However, I do have some experience with the 582 in a Zenith 701. Although the 2-stroke engines are not as reliable as the 4-stroke engines the 582 is one of the best of the Rotax 2-strokes. Mine had the HAC(high altitude compensation) carb kit and oil injection which made it very convenient. Unless you plan to fly a long way from home into the mountains the HAC would not be much of a benefit to you in the lowlands. The primary reason I'm responding to your inquiry though is that my wife and I spent a year in your beautiful country, from July 1990 - June 1991 on an engineering contract and traveled throughout your delightful country, including Enschede. I lived in Amstelveen, a suburb of Amsterdam. It was a sad day when my contract expired. Goed geluk with your Kolb acquisition efforts. Thom Riddle Buffalo, New York ________________________________ Message 3 _____________________________________ Time: 05:54:11 AM PST US From: Charles & Meredith Blackwell Subject: Kolb-List: prebuy check --> Kolb-List message posted by: Charles & Meredith Blackwell Pollus, You have made an excellent choice of an airplane. I fly a MKII, the earlier version of the same design with 5 inch tubes instead of the stronger 6 inch on the MKIII. It was easy for me to buy the plane because it belonged to my flight instructor and he pointed out the weaknesses and strengths to me and luckily he was an honest man. I will share some of that insight with you and what I have gained from my ownership. Keep checking the Kolb-list because the builders are very helpful and will have more information. The steel parts can rust if not properly treated and maintained. Check the hinge line for the ailerons and the elevators. The hinge can be replaced with a minimum of effort and time if needed. Also the tail has an "H" shaped bracket tying the tail boom to the rudder and the tail wheel. Some have found cracks on the angle tube going to the tail wheel, but that is extremely rare and a sign of a hard landing or interior rust through. The steel of the cockpit cage can rust if not sealed when welded. It will look like streaks of rust at the weld lines showing through the paint. If the paint is cracked or spiderwebbed on the cage, then that can be a sign of bending from rough treatment. Where the tailboom enters the cage in the rear, the supports should all be straight and symettrical, no signs of bending and cracking. While looking there, look at the tail boom, there should be no dents, especially on the top where the propeller may have struck the boom during an accident. All planes have slight dimples on the tail boom, but not hard creases or more than a few millimeters deep spread out over a space the size of a few fingers. The aluminum is fragile and dents during shipping and storage do occur. All fabric planes like ours hate the sun and if stored outside you may have fabric that needs replacing. The UV radiation breaks down the fabric. Some flying clubs have a testing tool to check fabric strength. If you can't find one then poke gently with your finger in the back near the propeller on the cage fabric. With light pressure it should give a little but feel like a drum. The paint should not flake off when you do this. Most older planes have rub marks in the fabric where it gets handled or bumped in the hangar. They should be limited, without large tears or spreading lines. This happens especially where you get in and out of the plane, on the tail surfaces and the wing tips. The propellor should not have cracks or holes in it. The engine should not leak excessive oil or any coolant. Most two sroke engines leave a little bit of oil from the exhaust on the plane, but not any real leaks or drips. The exhaust system should have no cracks in it, the springs should be strong that hold it together if they use that method. The exhaust gas temperature gauges should be connected and you can check the factory book against the rpm, the EGT and the cylinder head temperature figures during idle and warm up on the ground. You can check the compression of the cylinders to see if they are worn and need to be fixed. There should be minimal movement where the propeller connects to the gearbox, no sloppiness. You don't want rust where the tires connect to the landing gear legs. That is a stressed part and should be strong. There should be tread left on the tires, no threads showing through. Test the brakes. The leading edge of the wing should be straight and true, no bending or warping or sagging. The BRS parachute has a time limit on when it needs to be repacked or the propellant needs to be replaced. You can check the dates on the canister or soft pack case. If you find any faults, you can check on the price to fix them and see if it is worth it. Because most of the plane is visible, you can do a check easily. Try to get some time flying with an instructor in a Kolb MKIII before you fly your own. Good luck with your new bird. Charlie, MKII in NJ ________________________________ Message 4 _____________________________________ Time: 06:50:13 AM PST US From: "Paul Petty" Subject: Kolb-List: Ms. Dixie report --> Kolb-List message posted by: "Paul Petty" Morning Kolbers, Yesterday was an exciting day in the Kolbra shop! Ms. Dixie stood on her gear for the first time. http://www.c-gate.net/~ppetty/photos/PA310011.JPG Future Kolbra Pilot Charley makes first hanger flight. http://www.c-gate.net/~ppetty/photos/PA310007.JPG I think he approved. http://www.c-gate.net/~ppetty/photos/PA310008.JPG I wonder at this point if Travis gave me the correct tail boom. This thing looks 40 feet long! http://www.c-gate.net/~ppetty/photos/PA310009.JPG Mark has finished the fuel cell and is making her radiator/oil tank mount and as soon as it arrives it's on to the floor panels and panel. This is really starting to get interesting! Paul Petty Building Ms. Dixie Kolbra/912UL/Warp www.c-gate.net/~ppetty ________________________________ Message 5 _____________________________________ Time: 07:36:28 AM PST US From: "boyd young" "Kolb-List Digest Server" Subject: Kolb-List: Re: best lift to drag speed. 0.07 FORGED_OUTLOOK_TAGS Outlook can't send HTML in this format --> Kolb-List message posted by: "boyd young" Boyd, You are implicitly assuming that the prop has a constant efficiency for all speeds. Unfortunately, especially for fixed-pitch props, they don't. Their efficency varies significantly with speed - that's why a climb prop and a cruise prop have such different performance characteristics. Aircraft climb is essentially the power delivered by the prop minus the power required by the aircraft. Both must be considered, not just the aircraft side of the equation. Regards, Dave Paule Boulder, CO FSII dave ok I see what you are getting at..... but I think you need to take into consideration 2 graphs. 1. there is a graph for the climb rate over different speeds. at the best L/D speed for the airplane, that graph will max out. 2. the graph for prop efficiencies plotted over the range of speeds that we fly. and you could have a different graph for different props or pitches on the same prop. if you had a prop that has significantly better efficiency, faster or slower, than the best L/D speed then you would have a point..... but I think that any prop efficiency in the range of speed that we fly ( L/D speed + or - 20 ) do not change significantly enough to overcome the additional drag induced by the faster or slower speeds. boyd ________________________________ Message 6 _____________________________________ Time: 07:47:53 AM PST US From: John Jung Subject: Re: Kolb-List: Considering to buy second hand Kolb MK3: Where to watch out for? --> Kolb-List message posted by: John Jung Pollus and Group, When I have evaluated a plane to buy, I considered two things: the design and the workmanship. Kolbs are all well designed, so that part is easy. Workmanship is fairly easy, too. Get one that you are satisfied with. I consider workmanship important with other designs because it is an indication of how thorough the builder was. Even and expert can see everything and must rely to a large extent on workmanship to evaluate a plane. After building my Kolb, I decided that a builder would really have to screw up to build an unsafe one. Now that I've said that let me add one caution. If I were you, I would avoid of any Kolb where the builder made changes to the flight structure. Not that all changes are bad, it's just that they would need an expert to evaluate them. John Jung _______________________________ Express yourself with Y! Messenger! Free. Download now. ________________________________ Message 7 _____________________________________ Time: 07:52:50 AM PST US From: "PATRICK LADD" Subject: Re: Kolb-List: Re: best lift to drag speed. --> Kolb-List message posted by: "PATRICK LADD" <> This is all very true but this started out by talking about the way an a/c behaves after the engine stopped and the efficiency of the prop is irrelevant. In fact the prop is a darned nuisance as it degrades the gliding performance. There are only 2 speeds which the pilot should remember 1) the speed which will keep him in the air for the longest TIME. and 2) The speed which will keep him in the air for the longest DISTANCE. Cheers Pat pj.ladd@btinternet.com do not archive ________________________________ Message 8 _____________________________________ Time: 08:08:50 AM PST US From: "PATRICK LADD" Subject: Re: Kolb-List: Considering to buy second hand Kolb MK3: Where to watch out for? --> Kolb-List message posted by: "PATRICK LADD" <> Hi Pollus, I cannot help with tips on possible weak spots in an existing plane. Nearly everyone on this list has more experience than I . However, regarding flying.You show good sense in not trying to fly without instruction. Suggestion. Come to England for a holiday and contact the UK and European dealer Mike Moulai on www.sfmicrolights.com and see if he can arrange some instruction for you. You may want to wait for some reasonable weather of course.! Good luck Pat pj.ladd@btinternet.com Do not archive ________________________________ Message 9 _____________________________________ Time: 08:19:37 AM PST US From: "John Williamson" Subject: RE: Kolb-List: Ms. Dixie report --> Kolb-List message posted by: "John Williamson" Hi Paul, Great update on Ms. Dixie. They do look extremely long until you get the wings on them. John Williamson Arlington, TX Kolb Kolbra, Rotax 912ULS, 698 hours http://home.comcast.net/~kolbrapilot Zenith CH701 Project http://home.comcast.net/~stol_airplane http://www.zenithair.com/bldrlist/profiles/stol_airplane do not archive ________________________________ Message 10 ____________________________________ Time: 08:51:59 AM PST US From: "Jeremy Casey" Subject: Kolb-List: Best climb... 0.00 FORGED_RCVD_HELO Received: contains a forged HELO --> Kolb-List message posted by: "Jeremy Casey" I know what David P. is talking about. Basically best glide speed is the speed at which the airframe has the least TOTAL amount of drag. What David is saying (I think) is that depending on prop/engine configuration the best climb rate is not necessarily the same speed as best glide speed (in defense of several earlier posts by myself and John Williamson, we said "usually" is the same.) Case in point, consider your typical VW powered speedster, Sonex/Sonerai, etc. Climb is generated by excess thrust, not excess lift, so best climb is at a speed somewhere between the lowest TOTAL airframe drag speed and the speed at which the engine/prop make the most thrust. In other words the speed where the engine/prop combination make the most excess thrust over what is required to overcome that TOTAL airframe drag. In the case of VW powered planes with short prop diameters, they are terribly inefficient at converting torque to thrust at low airspeeds, so if lowest TOTAL airframe drag is at 65 but the prop doesn't really start to "hook up" till 85 then your best climb will obviously be higher then the lowest drag speed (which will be Best Glide speed) NOW! If anyone is still awake I will again state that USUALLY Best glide is pretty close to best climb on the airspeed indicator FOR TYPICAL ULTRALIGHTS/CESSNA'S/PIPER'S/etc. Obvious exceptions being planes like VW powered stuff with ridiculous short props, and most anything powered with a jet of anykind. F15/F16/Su-37/etc. ;-) Jeremy Casey KiloCharlie Drafting, Inc. jeremy@kilocharlie.us ________________________________ Message 11 ____________________________________ Time: 09:06:32 AM PST US From: "James, Ken" Subject: Kolb-List: Las Vegas --> Kolb-List message posted by: "James, Ken" Hey I'm going out to Las Vegas for a training seminar and have a weekend free Dec 4-5 any "air activities I should see/ do" Ken ________________________________ Message 12 ____________________________________ Time: 02:20:36 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: best lift to drag speed. --> Kolb-List message posted by: "John Hauck" speed which | will keep him in the air for the longest TIME. and 2) The speed which will | keep him in the air for the longest DISTANCE. | | Cheers | | Pat Hi Pat/All: I think the most important speed is the speed that keeps one flying and not stalling. Usually, in my case anyhow, I am too low to worry about best glide distance and minimum rate of decent. Our speed envelope is pretty small on our Kolbs, so I don't get wrapped around the axle too much on either best glade or minimum rate of decent. Usually, pretty busy trying to make the forced landing. Take care, john h ________________________________ Message 13 ____________________________________ Time: 04:06:02 PM PST US From: "Jon Croke" Subject: Kolb-List: my Firestar's longest trip w/o leaving the ground! --> Kolb-List message posted by: "Jon Croke" Dear fellow Kolbers, I have a unique story of woe and intrigue that I would like to share with you... providing a potential lesson in one of the dangers of Kolb ownership, or more accurately -- just some light entertainment. The story just ended its journey this last weekend. So here goes.. Back in August I got an inquiry on my Firestar, which I put up for sale to in order to help fund my new aircraft project. This gentleman, who we will call Joe, lives in Florida, and asked a bunch of questions about the plane's condition, history, etc. He satisfied himself to the degree that he sent me a postal money order for $500 as a deposit until he drove up here (I live near Green Bay, Wisconsin) to inspect the plane and decide whether to purchase. Well, the hurricanes started to hit Florida, one after another.. and our Joe could not make it up here for inspection. Of coure, I told him not to worry, he could take as long as needed, as I had his deposit and knew he was serious. And -- the plane was as described in my pictures and descriptions. After a few months, the hurricanes were done and Joe prepared himself for the journey up here. I had turned down at least 3 serious callers that wanted me to sell them my plane in the meantime, but I told them that the deposit from Joe precluded me from offering it to anyone else. Joe finally was ready to make his journey to visit the plane, and advised me via email of his departure. Then, I got the following email about 10 hours after he left: "Jon, traveling up RT 75 towards Atlata Georga I decided I can't do it. I give up on my dream to own and fly my own plane.Its just too much for this 65 year old man. All I could think of is trailering it home, thats a long way 1400 miles towing a trailer with a plane on it. I thought of so many things that could go wrong. I'm driveing a 19 year old truck ( in very good shape ) but anything going wrong would delay me, I would not leave my plane on a open trailer unguarded. I sold my last airplane in 1993 and have not flown since, thats 11 years ago. I still dream of flying but I have to be realisic.The closest airport is 35 miles away, no instruction there. I would need to get current, closest airport about 50 miles 6000 ' paved strip, not my kind of place. I guess its just a imposible dream, keep the deposit, sell it to someone else. I will not try again ! SORRY for delaying you. Joe " Well, poor Joe, I didnt want to lose the sale of the plane if it was just the long journey that troubled him, plus I didnt want to keep his deposit although I knew I lost several buyers during those months that went by. So, I sent him an email offering to bring him the plane on my own nickel, (about 1600 miles each way with 2.5 days travel time) -- if he was still interested. One of the many emails from him responding to my offer inlcude this one: "Jon you are too kind ! tell me the details on bringing it down and how we can work it out ( details ). I'm sorry if I'm a little short, I'm still upset about my 5th wheel. You know I am interested and want your Kolb firestar ll. Thank You ... Joe" and the evening before I left, this email: " Hi Jon, I will be ready and waiting, give me a call along the way collect is fine ! I will be home most of the time. We can make final directions so we can hook up. Don't forget plans, manuals, spare parts ,anything, as now is the time to put them in that trailer. See you soon.... Joe " Well, I started my long journey with Firestar in tow... realizing I was only getting 10 miles per gallon pulling that trailer (enclosed) and taking the long route around the Smoky mountains to make the journey smoother. After a couple of long days I arrived close to his home and called hom from my motel room. We agreed to meet at Zepherhills airport at 11:00 AM where the plane would be kept. Now here is where the story takes a turn. Joe arrived at the airport and we together walked into the FBO to rent a tie down area where the plane would live. I pulled the trailer onto that grass spot to start the process of unloading (which is an involved process of undoing the packing, ramps, etc) Well, I suspected something strange when Joe stopped me from starting the unpacking and requested we get a soft drink from the FBO first. I agreed and we chit chatted about nothing much while we finished our drinks. I was starting to get nervous, but wasnt sure why! Well, we then went back to the trailer, he took a quick look thru the trailer and I started to remove the first ramp. He stopped me at the back end of the trailer, told me to STOP and jammed $500 in bills into my hand. He said "Jon, I dont want the plane" I am getting old, I cannot handle what it takes to put this together, I have so many projects to finish, I am REALLY sorry, but I cannot deal with the plane" Well... that was about it.... but since I really didnt want to bring the plane all the way home, and lose the sale, I sat Joe down, and presented him with a sheet of paper with some figures on it. I offered to reduce the price by $2000 + another $1000 credit for the money he had given me so far (deposit) no questions asked, just to get him to take the plane. No thanks was his answer. I made that long slow trip home, with the plane in tow, and my tail between... (wherever your tail goes)! What lessons should I learn from all of this?? I was mad about the fact that I had wasted 5 days of my life driving across the country... The $1000 I got from Joe just barely covered my gas and 5 days of hotels (3200 mi and $2 gal for gas), I should be lucky for that, tho. I guess I'm glad that Joe is not a fellow Kolb owner, we dont need his kind! (I'm still a little bitter). Maybe I should have read between the lines in his original letter when he turned back on his journey. I am not a good judger of situations, I suppose. What remains now is a Firestar for sale, the flying season is virtually over for up here... so if anyone would like to take advantage of an end of season sale, I'm willing to deal.... and if you would like me to bring the plane to your door for inspection...... well......better have a strong drink for me... http://joncroke.com for pics and details. DO NOT ARCHIVE ________________________________ Message 14 ____________________________________ Time: 04:46:31 PM PST US From: "David Paule" "Kolb-List Digest Server" Subject: Kolb-List: Re: best lift to drag speed. 0.00 THE_BEST_RATE BODY: The best Rates 0.00 FORGED_RCVD_HELO Received: contains a forged HELO 0.07 FORGED_OUTLOOK_TAGS Outlook can't send HTML in this format --> Kolb-List message posted by: "David Paule" Okay students, please get out a piece of graph paper, a ruler, and a black, a blue, and a red pencil, and we'll look at an imaginary airplane. Why not? Great Hallow's Eve has passed and the air is still full of magic. Let's assume that this magic airplane has two perfect power settings: full power and idle power, and that it'll happily run all day at either of these. Please pick up your black pencil. In the middle of the page, draw a horizontal line across the page. Label this line "speed," and number it from 0 at the left to 100 at the right. We'll call these speeds mph. At the 0 mark on the line, draw a vertical line the full height of the page. Since it's already labeled 0 at the crossing, mark it to 1,000 feet per minute at the top of the page, and -1,000 feet per minute at the bottom. Draw a vertical line at 32 mph. This is the stall speed. Please pick up the red pencil for our idling motor, and make three dots at these points: a) Stall speed and -500 feet per minute, b) 38 mph and -250 feet per minute, c) 70 mph and -700 feet per minute. Draw a parabola through these points. Now kindly use the blue pencil, for the full-power case, and make three dots at these points: a) Stall speed and 250 feet per minute up, b) 42 mph and 750 feet per minute up, c) 70 mph and 0 feet per minute. And draw a blue parabola through these. Both parabolas should not hold water. Next, get the black pencil again and draw these lines: 1. From the origin to a tangency with the blue parabola. That speed is Vx. 2. A vertical line through the maximum part of the blue parabola. That's the best rate of climb speed, probably at 42 mph, and it's called Vy. 3. From the origin to the tangency of the red parabola. This speed is the best L/D speed. The reciprocal of the slope of the line is the best L/D. 4. A vertical line through the highest point of the red parabola. This is the speed for the minimum rate of sink, probably at 38 mph. 5. There's a final point worth noting - where the blue line crosses the speed axis, that's the top speed. Now, if you wish, you can draw another arc. This one - any yes, certainly, you can use another color. In fact, I recommend it - is the rate of climb from the blue line minus the rate of sink from the red line. This line is called the "excess power available" curve. If your graph looks at all like mine, the shape of this curve is a smooth parabola. Its peak value is at about 50 mph, for good all-around performance. It's not centered on the L/D point. Obviously all this varies for different weights, props, etc. A myriad of factors. The thing is that our measurements are of a whole plane, not just the airframe. It has a motor and a prop. And rate of climb is only due to the excess power available. No excess power and you'd simply have a wide car. Now, unfortunately, I must go off on an errand, so this lesson is ended for tonight. Enjoy, Dave Paule Boulder, CO FSII +++++ ----- Original Message ----- From: boyd young To: David Paule ; Kolb-List Digest Server Sent: Monday, November 01, 2004 8:24 AM Subject: Re: best lift to drag speed. Boyd, You are implicitly assuming that the prop has a constant efficiency for all speeds. Unfortunately, especially for fixed-pitch props, they don't. Their efficency varies significantly with speed - that's why a climb prop and a cruise prop have such different performance characteristics. Aircraft climb is essentially the power delivered by the prop minus the power required by the aircraft. Both must be considered, not just the aircraft side of the equation. Regards, Dave Paule Boulder, CO FSII dave ok I see what you are getting at..... but I think you need to take into consideration 2 graphs. 1. there is a graph for the climb rate over different speeds. at the best L/D speed for the airplane, that graph will max out. 2. the graph for prop efficiencies plotted over the range of speeds that we fly. and you could have a different graph for different props or pitches on the same prop. if you had a prop that has significantly better efficiency, faster or slower, than the best L/D speed then you would have a point..... but I think that any prop efficiency in the range of speed that we fly ( L/D speed + or - 20 ) do not change significantly enough to overcome the additional drag induced by the faster or slower speeds. boyd ________________________________ Message 15 ____________________________________ Time: 05:03:25 PM PST US From: "Larry Bourne" Subject: Re: Kolb-List: my Firestar's longest trip w/o leaving the ground! --> Kolb-List message posted by: "Larry Bourne" Jon, I'm amazed. I can't believe the patience and effort you expended for this guy. I guess you did get a free sightseeing trip out of it all, but what a pain in the ........., and you've gotta start all over to sell the plane. Good Luck. Lar. Do not Archive. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "Jon Croke" Subject: Kolb-List: my Firestar's longest trip w/o leaving the ground! > --> Kolb-List message posted by: "Jon Croke" > > Dear fellow Kolbers, > > I have a unique story of woe and intrigue that I would like to share with > you... providing a potential lesson in one of the dangers of Kolb > ownership, or more accurately -- just some light entertainment. The story > just ended its journey this last weekend. So here goes.. > ________________________________ Message 16 ____________________________________ Time: 05:53:26 PM PST US From: jerb ground! Subject: Re: Kolb-List: my Firestar's longest trip w/o leaving the ground! --> Kolb-List message posted by: jerb ground! Jon, Sorry to hear of your recent experience. Want to sell it post it on Barnstormer.com - they work on donations if you sell it. (I figure its worth the amount it would cost to publish in the UL Flying magazine or our local metro paper) - it will be snatched up quicker than you think. A good plane at a fair price will not last long. Got to admit your pretty brave taking a trip on condition of a sight unseen purchase facing there is a high risk that the potential buyer could back out and not have much to loose in the process. Did this happen this last week - you know they had the Sport Aviation Expo in Sebring FL Thursday through Sunday. Repost the info regarding your plane to the Kolb site. Here's a heads up of a scam some sellers have bit on. It goes down like this. Someone contacts you wanting to purchase your plane. They then propose that another party who owes them a sum being more than the purchase price will send you a check. They ask that you cash the check, withhold the amount due you and then forward the difference to them. Some cases they get you to send the check, in others they pickup the plane and the check. You soon learn that the check send to you is worthless. You will not see your money nor the plane again. jerb ________________________________ Message 17 ____________________________________ Time: 07:07:20 PM PST US From: "Larry Cottrell" Subject: Re: Kolb-List: Best climb... --> Kolb-List message posted by: "Larry Cottrell" > > NOW! If anyone is still awake I will again state that USUALLY Best glide > is pretty close to best climb on the airspeed indicator FOR TYPICAL > ULTRALIGHTS/CESSNA'S/PIPER'S/etc. You guys are getting a bit technical for me, but for what it is worth I did some experimenting with my Firestar in the desert where landing was not a problem. It was pretty simple and of course primitive, but my objective was to see what speed would give me the longest distance. I climbed 3000 ft above the ground and shut the motor off, kept the plane as close to 45 as I could. I might mention the I was 6 miles by gps from camp. Noted how close to camp I managed to land. Next I went to the same altitude and distance and did it again this time at 55. There was no appreciable difference in distance, I just got there sooner. Probably did something wrong??? Any way I was a bit surprised and decided that I would just pick the best spot and make sure that I either got there or picked another one that I could get to. If I am not mistaken it is generally trying to stretch the glide that causes the most serious problems. Besides all that stuff makes my brain hurt. Its too old for all that exercise. Larry, Oregon ________________________________ Message 18 ____________________________________ Time: 07:11:32 PM PST US From: "John Williamson" Subject: RE: Kolb-List: Re: best lift to drag speed. --> Kolb-List message posted by: "John Williamson" David, I'm sorry but you seem to have lost sight of what has been said. L/D max gives you minimum rate of descent when power is reduced. L/D max gives you best rate of climb with power applied. L/D max is based on the airfoil not on the engine/prop configuration. L/D max is determined by flight testing and varies with several variables. Any speed above the stall speed is good, but the speed that gives you L/D max (minimum sink) is a good number to remember. John Williamson Arlington, TX Kolb Kolbra, Rotax 912ULS, 698 hours http://home.comcast.net/~kolbrapilot Zenith CH701 Project http://home.comcast.net/~stol_airplane http://www.zenithair.com/bldrlist/profiles/stol_airplane do not archive ________________________________ Message 19 ____________________________________ Time: 07:21:03 PM PST US From: tj brown Subject: Re: Kolb-List: my Firestar's longest trip w/o leaving the ground! --> Kolb-List message posted by: tj brown Try putting your plane on www.ultralighthomepage.com Its free and you can even put a free photo up. TJ jerb , UNEXPECTED_DATA_AFTER_ADDRESS@.SYNTAX-ERROR. wrote: --> Kolb-List message posted by: jerb ground! Jon, Sorry to hear of your recent experience. Want to sell it post it on Barnstormer.com - they work on donations if you sell it. (I figure its worth the amount it would cost to publish in the UL Flying magazine or our local metro paper) - it will be snatched up quicker than you think. A good plane at a fair price will not last long. Got to admit your pretty brave taking a trip on condition of a sight unseen purchase facing there is a high risk that the potential buyer could back out and not have much to loose in the process. Did this happen this last week - you know they had the Sport Aviation Expo in Sebring FL Thursday through Sunday. Repost the info regarding your plane to the Kolb site. Here's a heads up of a scam some sellers have bit on. It goes down like this. Someone contacts you wanting to purchase your plane. They then propose that another party who owes them a sum being more than the purchase price will send you a check. They ask that you cash the check, withhold the amount due you and then forward the difference to them. Some cases they get you to send the check, in others they pickup the plane and the check. You soon learn that the check send to you is worthless. You will not see your money nor the plane again. jerb ________________________________ Message 20 ____________________________________ Time: 07:21:37 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Best climb... --> Kolb-List message posted by: "John Hauck" that causes | the most serious problems. Besides all that stuff makes my brain hurt. Its | too old for all that exercise. | Larry, Oregon Hi Larry/Gang: I understand you completely. :-) Looking forward to the day I can join you all and fly Alvord. Take care, john h DO NOT ARCHIVE