---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Wed 07/28/10: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:39 AM - Too many questions (Vic) 2. 07:39 AM - Too many questions (Lanny Fetterman) 3. 09:33 AM - Re: Too many questions (Dana Hague) 4. 03:27 PM - Re: Too many questions (russ kinne) 5. 04:09 PM - Re: Too many questions (Vic) 6. 04:33 PM - Re: Too many questions (Richard Girard) 7. 05:37 PM - Re: Too many questions (Charlie England) 8. 09:01 PM - Re: landing lights (willuribe@aol.com) 9. 09:19 PM - Re: landing lights (willuribe@aol.com) ________________________________ Message 1 _____________________________________ Time: 06:39:57 AM PST US From: "Vic" Subject: Kolb-List: Too many questions Hi all How does one calculate 75% power? % of max rpm or % of wot level flight? Same for best angle of climb and best rate. How far north do you have to fly to be rid of 90 degree humid weather? Vic in Maine 912ul xtra ________________________________ Message 2 _____________________________________ Time: 07:39:32 AM PST US From: Lanny Fetterman Subject: Kolb-List: Too many questions Vic, I can`t answer your first two questions, as for the last question. It was 82 degrees and very hazy when I landed last night at 8:15 in Pennsylvania. I was sweating bullets when I got finished unfolding the FSII at 7:00. Flying into the sun the visibility was terrible. So I know for sure, you need to go farther north then Pa. for cool weather. ;-) Lanny N598LF ________________________________ Message 3 _____________________________________ Time: 09:33:24 AM PST US From: Dana Hague Subject: Re: Kolb-List: Too many questions At 09:34 AM 7/28/2010, Vic wrote: >Hi all >How does one calculate 75% power? % of max rpm or % of wot level flight? Neither... it's the rpm corresponding to 75% power on the engine manufacturer's published HP curve. > Same for best angle of climb and best rate. Through actual testing at various speeds. -Dana -- Clothes make the man. Naked people have little or no influence on society. ________________________________ Message 4 _____________________________________ Time: 03:27:55 PM PST US From: russ kinne Subject: Re: Kolb-List: Too many questions Vic Doesn't Rotax supply that info? And try the north end of Baffin Island. It's great in July & August! But few airfields do not archive On Jul 28, 2010, at 9:34 AM, Vic wrote: > Hi all > How does one calculate 75% power? % of max rpm or % of wot level > flight? > > Same for best angle of climb and best rate. > > How far north do you have to fly to be rid of 90 degree humid weather? > > Vic in Maine > 912ul > xtra > > ________________________________ Message 5 _____________________________________ Time: 04:09:21 PM PST US From: "Vic" Subject: Re: Kolb-List: Too many questions Vic Doesn't Rotax supply that info? And try the north end of Baffin Island. It's great in July & August! But few airfields do not archive On Jul 28, 2010, at 9:34 AM, Vic wrote: Hi all How does one calculate 75% power? % of max rpm or % of wot level flight? Same for best angle of climb and best rate. How far north do you have to fly to be rid of 90 degree humid weather? Vic in Maine 912ul xtra Yup I found it. 75% power is 5000 rpmBut how would rotax know anything about kolb performance? ________________________________ Message 6 _____________________________________ Time: 04:33:31 PM PST US Subject: Re: Kolb-List: Too many questions From: Richard Girard Vic, Look in the operations manual pages 10-4 for the 912 UL and 10-8 for the 912 ULS 75% power for both is at 5000 RPM. Rick Girard On Wed, Jul 28, 2010 at 5:25 PM, russ kinne wrote: > Vic > Doesn't Rotax supply that info? > And try the north end of Baffin Island. It's great in July & August! > But few airfields > do not archive > > On Jul 28, 2010, at 9:34 AM, Vic wrote: > > Hi all > How does one calculate 75% power? % of max rpm or % of wot level flight? > > Same for best angle of climb and best rate. > > How far north do you have to fly to be rid of 90 degree humid weather? > > Vic in Maine > 912ul > xtra > > * > > > href="http://www.matronics.com/Navigator?Kolb-List">http://www.matronics.com/Navigator?Kolb-List > href="http://forums.matronics.com">http://forums.matronics.com > > href="http://www.matronics.com/contribution">http://www.matronics.com/contribution > * > > ________________________________ Message 7 _____________________________________ Time: 05:37:08 PM PST US From: Charlie England Subject: Re: Kolb-List: Too many questions > On Wed, Jul 28, 2010 at 5:25 PM, russ kinne > wrote: > > Vic > Doesn't Rotax supply that info? > And try the north end of Baffin Island. It's great in July & August! > But few airfields > do not archive > > On Jul 28, 2010, at 9:34 AM, Vic wrote: > >> Hi all >> How does one calculate 75% power? % of max rpm or % of wot level >> flight? >> Same for best angle of climb and best rate. >> How far north do you have to fly to be rid of 90 degree humid >> weather? >> Vic in Maine > Unfortunately, knowing only RPM isn't adequate to calculate horsepower. HP is Torque in foot lbs times RPM, divided by 5252. A somewhat meandering explanation is at http://horsepowersports.com/torque.php or just Google & start reading. To have any meaning, the RPM number in the Rotax manual should specify, at minimum, manifold pressure, airframe, and propeller. Consider the same engine/prop at 5000 RPM on something like a Kolb, then on a Van's RV-12 (remember, same prop, too). 5k RPM on the Kolb might be 75%, but would likely be closer to 50% power on the RV-12, because the cleaner airframe would need a much lower torque figure to reach 5k RPM. Taken to extremes, consider the engine with no prop at all at 5k RPM. The only horsepower would be what's required to overcome internal engine friction & 'pumping losses'. Here's a relatively simple way to find 75% for a normally aspirated engine: climb to roughly 7500feet density altitude, apply full throttle with your prop pitched to turn the RPM at which the engine manufacturer specifies *FULL* power. If you are turning the RPM for full throttle, full power but you're at 7500 feet altitude, you're making pretty close to 75% power. If you have a manifold pressure gauge, make a note of the reading. If, at lower altitudes, you can set that manifold pressure & turn the same RPM (the 'full power' RPM), you'll still be making around 75% power. This isn't exact, but it is in the ballpark. Rotax should have a chart with RPM on one axis and manifold pressure on the other, and a line that defines 75% power (effectively an infinite number of combinations). As to the temp/humidity issue, drive south & gain a lasting appreciation for 90 degrees & 'humid'. :-) We used to laugh our heads off at Harry Caray broadcasting daytime Cubs games & complaining about the 'brutal 83 degrees & 65 percent humidity.' A 95/95 or 95/100 temp/humidity day is far too common (100+/95 isn't rare) down here 100-150 mi north of the Gulf. Charlie RV-7 under construction, but wishing for a Kolb here at Slobovia Outernational ________________________________ Message 8 _____________________________________ Time: 09:01:14 PM PST US Subject: Re: Kolb-List: landing lights From: willuribe@aol.com Greetings, Attached is a picture the new LED landing light from superbrightLED.com it works much better then the one I used before, the halogen light is a little yellow because the battery is low but still cast a longer beam on the hanger floor. http://www.youtube.com/watch?v=UCpLVKWz_2o Disco fever http://www.youtube.com/watch?v=HMCiHyZuo30 again the battery is low so the strobes are not flashing as fast as normal .. Regards, Will Uribe El Paso, TX FireStar II ________________________________ Message 9 _____________________________________ Time: 09:19:40 PM PST US Subject: Re: Kolb-List: landing lights From: willuribe@aol.com ------------------------------------------------------------------------------------- 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.