---------------------------------------------------------- Kitfox-List Digest Archive --- Total Messages Posted Sun 10/10/04: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:53 AM - Measuring speed. WAS: VG flight testing (Michel Verheughe) 2. 06:08 AM - Re: Trailering (John Larsen) 3. 06:51 AM - Re: Trailering (Flier) 4. 07:54 AM - Re: Measuring speed. WAS: VG flight testing (Brian Peck) 5. 09:19 AM - Re: Re: KitFox N210F "HEAVY" (Randy Daughenbaugh) 6. 04:27 PM - Re: Re: KitFox N210F "HEAVY" (kurt schrader) 7. 06:39 PM - Grove Landing Gear (Jimmie Blackwell) 8. 06:43 PM - Re: Grove Landing Gear (AlbertaIV@aol.com) 9. 06:49 PM - Re: Grove Landing Gear (Dcecil3@aol.com) 10. 08:20 PM - Re: Grove Landing Gear (Clint Bazzill) 11. 10:01 PM - Re: VG's and the testing process (jimshumaker) 12. 10:37 PM - Re: Barrel Rolls (kurt schrader) 13. 11:15 PM - Re: Landings in 49 States (kurt schrader) 14. 11:18 PM - Re: Oil Tank Vent (kurt schrader) ________________________________ Message 1 _____________________________________ Time: 03:53:43 AM PST US From: Michel Verheughe Subject: Kitfox-List: Measuring speed. WAS: VG flight testing --> Kitfox-List message posted by: Michel Verheughe Brian Peck wrote: > Using GPS to determine stall speeds is problematic because it gives you > groundspeed. In my POH, there is a written Vso for my plane. It has been overwritten by the builder, at the time of completion testing, to 40 MPH. Indeed, the plane stalls at that indicated speed, but is it the true speed? The only check I could think of is this: A windless day, I flew with a passenger (my son) and the GPS on. When the windsock hangs down motionless, it is windless over the ground but not necessarily at say, 500 ft AGL. So, I did a landing, stalling in three-points position. I did the landing, my son did the reading. And yes, the IAS and GPS GS were identical and 40 MPH. I know now that my pitot tube is reading correctly even at about a 16 degrees nose-up attitude. My observation from slow sailing GPS reading is that it is pretty well integrating speed and heading, especially since the Selective Availability has been removed (thanks, Mr. President Clinton!) Tacking (turning 90 degrees) at say 4 knots, reads a new heading within a few seconds. GPS is a navigator's dream come true. Cheers, Michel ________________________________ Message 2 _____________________________________ Time: 06:08:46 AM PST US From: John Larsen Subject: Re: Kitfox-List: Trailering --> Kitfox-List message posted by: John Larsen If you trail your plane nose first it is a good idea to plug the front spars. If your wings are not rib stiched, towing forward can let air pressure enter the wing through the spars and pop the fabric loose. kitfoxjunky wrote: >--> Kitfox-List message posted by: kitfoxjunky > >Good Point on the tail spring. I had to put the tail on the utility >trailer BEFORE I folded the wings, otherwise there was too much weight >back there to allow one person to pick it up. Maybe that utility trailer >idea is not so hot, although I cannot see any difference between using >that and having the airplane sit completely on a larger trailer in a three >point configuration. In both cases there is more weight on the tail >spring, and it will still bounce up and down with bumps in the road. Over >the winter I am going to build one of the trailer tow bars that attaches >to the rear of the fuse. That takes all the load off the tail spring and >distributes it better over the rear of the fuse. > >How did you configure those gas struts? Where did they attach to? > >Gary Walsh >C-GOOT >www.decisionlabs.com/kitfox > >--> Kitfox-List message posted by: "flier" > >I'd recommend watching that tailspring really close. > >Personally, I use gas struts to take the weight off >the tailspring as well as securing the tail via the >towbar crosstube independent of the tailspring. It >would really suck to have the tail come loose while >towing -- nearly as much as to have a wing come loose. > > > > ________________________________ Message 3 _____________________________________ Time: 06:51:26 AM PST US From: "Flier" Subject: RE: Kitfox-List: Trailering --> Kitfox-List message posted by: "Flier" You can see it in this pic. The struts are inset into two pieces of channel with slots at the top. The cross bolt rides in the slots (it's actually through a couple of bushings that the stop of the struts ride on). The whole assy pivots to unload. As I winch the plane back, I insert the crossbolt through the struts and fuse then winch on back and the struts take the load off the tail. Then a fixed crossbolt on the trailer secures the whole thing from movement. The only movement is the few inches up and down that the slots allow the fuse. http://www.foxflier.com/kitfox/Trailer/HPIM0253.jpg Regards, Ted -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com]On Behalf Of John Larsen Subject: Re: Kitfox-List: Trailering --> Kitfox-List message posted by: John Larsen If you trail your plane nose first it is a good idea to plug the front spars. If your wings are not rib stiched, towing forward can let air pressure enter the wing through the spars and pop the fabric loose. kitfoxjunky wrote: >--> Kitfox-List message posted by: kitfoxjunky > >Good Point on the tail spring. I had to put the tail on the utility >trailer BEFORE I folded the wings, otherwise there was too much weight >back there to allow one person to pick it up. Maybe that utility trailer >idea is not so hot, although I cannot see any difference between using >that and having the airplane sit completely on a larger trailer in a three >point configuration. In both cases there is more weight on the tail >spring, and it will still bounce up and down with bumps in the road. Over >the winter I am going to build one of the trailer tow bars that attaches >to the rear of the fuse. That takes all the load off the tail spring and >distributes it better over the rear of the fuse. > >How did you configure those gas struts? Where did they attach to? > >Gary Walsh >C-GOOT >www.decisionlabs.com/kitfox > >--> Kitfox-List message posted by: "flier" > >I'd recommend watching that tailspring really close. > >Personally, I use gas struts to take the weight off >the tailspring as well as securing the tail via the >towbar crosstube independent of the tailspring. It >would really suck to have the tail come loose while >towing -- nearly as much as to have a wing come loose. > > ________________________________ Message 4 _____________________________________ Time: 07:54:53 AM PST US From: Brian Peck Subject: Re: Kitfox-List: Measuring speed. WAS: VG flight testing --> Kitfox-List message posted by: Brian Peck On Oct 10, 2004, at 1:11 AM, Michel Verheughe wrote: > In my POH, there is a written Vso for my plane. It has been > overwritten by the > builder, at the time of completion testing, to 40 MPH. Indeed, the > plane stalls > at that indicated speed, but is it the true speed? > Michel, Doug Gray, at the National Test Pilot School, wrote an excellent paper on the subject of determining pitot static errors using GPS. You can download the paper and data sheets from their site at http://www.ntps.edu/HTML/Downloads/ I would suggest using this technique to verify/calibrate the airspeed indicator and then use the airspeed indicator in any further testing or operations. This is because the behavior of the aircraft (stall, etc) is directly related to IAS and is only indirected related to groundspeed. Also, when the airspeed is changing rapidly, such as during a stall break, the update rate on the GPS may not be fast enough to capture the speed at the right time; whereas the ASI gives an instantaneous reading. Cheers, Brian Peck ________________________________ Message 5 _____________________________________ Time: 09:19:52 AM PST US From: "Randy Daughenbaugh" Subject: RE: Kitfox-List: RE: KitFox N210F "HEAVY" --> Kitfox-List message posted by: "Randy Daughenbaugh" Kurt, So what did you get for Vx and Vy? Randy - an inquiring mind.... snip I am happy to say that I got some useful data from these tests. Now I have some very pretty graphs of Vx and Vy that changed only 3 knots with all that weight increase. I have stall vs weight graphs for each flap setting that change 11 knots for my whole weight range at zero flaps, but less change increasing toward max flaps. And I have gph vs speed and mpg vs speed graphs for x-country use. It goes from 12 to 20 mpg, BTW. Still a little draggy, but the weight increase didn't effect range much at all. 5% ??? I just always use the heavy range figures. snip Kurt S. S-5/NSI turbo _______________________________ Declare Yourself - Register online to vote today! http://vote.yahoo.com ________________________________ Message 6 _____________________________________ Time: 04:27:53 PM PST US From: kurt schrader Subject: RE: Kitfox-List: RE: KitFox N210F "HEAVY" --> Kitfox-List message posted by: kurt schrader Hi Randy, This is something that still bothers me. Vx and Vy are only 2-3 knots apart. I expected more of a spread. My Best ROC is from 57 to 60 KIAS (66-69 mph) depending on weight. My best angle is just 2-3 knots slower. (62-66 mph) The slope of the curve is steep and a few knots either way made a big difference. Just 2 knots slower cost me over 150'/minute. Two knots faster wasn't quite as bad, but close to 100'/min. The climb rate falls off as fast as the speed when slowing toward max angle, so your altitude gain per distance isn't helped by getting much slower then best ROC. I tend to cruise climb at 70 KIAS for cooling and visibility, but if I need to get up there, I need to lock in my best rate/angle speed within a knot or two. I have gotten Vx/Vy speeds slower than that, but only for really very light weights. Me solo and not much fuel. I did not test for best angle with flaps yet. I did some early on, but that was before my scoop and strut fairing mods, so that data is off. i expect that will help for obsticle clearance, but don't "know" it as a fact. Kurt S. S-5/NSI turbo --- Randy Daughenbaugh wrote: > --> Kitfox-List message posted by: "Randy > Daughenbaugh" > > Kurt, > So what did you get for Vx and Vy? > > Randy - an inquiring mind.... _______________________________ Declare Yourself - Register online to vote today! http://vote.yahoo.com ________________________________ Message 7 _____________________________________ Time: 06:39:52 PM PST US From: "Jimmie Blackwell" Subject: Kitfox-List: Grove Landing Gear --> Kitfox-List message posted by: "Jimmie Blackwell" I am considering ordering Grove main gear for my Model IV. There has been a lot of positive feedback on the Grove gear, but I just wonder has there been anyone that has tried the Grove gear and changed back to the bungee gear. Thanks Jimmie ________________________________ Message 8 _____________________________________ Time: 06:43:09 PM PST US From: AlbertaIV@aol.com Subject: Re: Kitfox-List: Grove Landing Gear --> Kitfox-List message posted by: AlbertaIV@aol.com In a message dated 10/10/04 6:40:26 PM Pacific Daylight Time, jablackwell@ev1.net writes: << I am considering ordering Grove main gear for my Model IV. There has been a lot of positive feedback on the Grove gear, but I just wonder has there been anyone that has tried the Grove gear and changed back to the bungee gear. Thanks Jimmie >> Jimmie, I can't imagine anyone doing that. Don Smythe N-998DS Classic IV W/ 582 ________________________________ Message 9 _____________________________________ Time: 06:49:53 PM PST US From: Dcecil3@aol.com Subject: Re: Kitfox-List: Grove Landing Gear --> Kitfox-List message posted by: Dcecil3@aol.com I had Grove Gear on my Challenger,I don't think anyone would change them back . The gear are maintenance free and just so smooth.Be like trading a Cadillac for a Horse. D Cecil ________________________________ Message 10 ____________________________________ Time: 08:20:34 PM PST US From: "Clint Bazzill" Subject: Re: Kitfox-List: Grove Landing Gear --> Kitfox-List message posted by: "Clint Bazzill" Anyone that would go from a spring gear back to a tubular gear should see a psychiatrist. Clint ________________________________ Message 11 ____________________________________ Time: 10:01:46 PM PST US From: "jimshumaker" Subject: Re: Kitfox-List: VG's and the testing process --> Kitfox-List message posted by: "jimshumaker" Kurt No I could not measure any difference in cruise or top speed. But my top sea level cruise speed is almost structural redline. Oh, I did in fact, use 17 degrees on the VG's also. Jim Shumaker. ----- Original Message ----- From: "kurt schrader" Subject: Re: Kitfox-List: VG's and the testing process > --> Kitfox-List message posted by: kurt schrader > > Thanks Jim, > > Did you lose much in cruise speed? > > I think that it could be my leading edge that is cnx > the improvement, though I am not getting a leading > edge stall, which is usually wicked. Moving them fwd > is a good idea to try. I might try them back up to 6" > too. > > Kurt S. > > --- jimshumaker wrote: > > > --> Kitfox-List message posted by: "jimshumaker" > > > > > > Hi Kurt > > > > Thanks for filling us in on your VG tests. I have a > > different wing and so > > my setup may not work for you. I did not get a > > reasonable improvement in > > stall until I moved the VG's to 3 inches from the > > leading edge. You might > > want to try that next year. Like you, I would not > > bother keeping them on > > unless there was enough improvement to make enough > > difference to put up with > > their drawbacks. > > > > Jim Shumaker. > > > > > > ----- Original Message ----- > > From: "kurt schrader" > > To: > > Subject: Re: Kitfox-List: VG's and the testing > > process > > > > > > > --> Kitfox-List message posted by: kurt schrader > > > > > > > > Stu and everyone, > > > > > > I also think this was very stimulating and like > > the > > > scientific mentality to challenge the process and > > > conclusions before accepting them. To me that > > process > > > is bigger and worth more than these single results > > > themselves. I applaud the challengers as those > > with > > > courage enough to promote this necessary > > corrective > > > proceedure. > > > > > > But I would especially like to find a cause and a > > cure > > > for not achieving a slower stall, and wish I had > > that > > > over any pride of authorship. I don't think we > > found > > > one yet. Darn... > > > > > > A few points to make to add to this: > > > > > > A. There was no significant difference in > > indicated > > > stall speeds. If a greater AOA was achieved, > > there > > > should have been some indicated difference, and > > pitot > > > error could then exerate that. I think the angles > > > were always the same for each flap setting no > > matter > > > what VG's were used, +/- a degree. > > > > > > B. One solution to pitot error is to mount the > > pitot > > > tube at a median downward angle so that it is in > > line > > > with the slip stream half way between zero AOA and > > > stall. That would produce an error of very small > > size > > > on either end of the AOA/speed range. I think > > that > > > the error was in fact small at the AOA's I > > achieved. > > > I suspect that only my power-on stall got near 20 > > > degrees and the others were around 16. > > > > > > C. But I have the silver bullet - TA DA - an AOA > > > probe, thanks to Elbie and RiteAngle. It points > > into > > > the slipstream and measures AOA directly. For all > > of > > > my stalls tests however, I turned it off so as not > > to > > > distract me or cause "stall anticipation". But > > for > > > later testing I can enable it and have it "report" > > > differences in stall angle, if any. Expect that > > next > > > year though. Too much to do for now. The VG > > testing > > > took 6 days I can't make up. I had hoped it would > > > work in a day or 2. > > > > > > Thanks for all the input. I hope someone finds a > > > better answer. > > > > > > Kurt S. S-5/NSI turbo > > > > > > --- Stu Bryant wrote: > > > > > > > Lowel, > > > > You are very knowledgeable about this, sir. > > Actually > > > > all of you participating in this thread are. > > > > > > > > I have no agenda one way or the other, and > > frankly > > > > do not disagree with any > > > > of the conclusions, either. I wasn't sure > > whether > > > > any potential skewing of > > > > the data by this theoretical dilemma would be > > > > positive or negative. I was > > > > merely concerned that there was potential for a > > > > skewing which might be > > > > difficult to detect. I just thought I saw an > > area > > > > where another > > > > consideration might potentially might be useful. > > > > Evidently with the given > > > > particulars this was not helpful. - OK, I accept > > > > that. > > > > > > > > > > > > You said "...so if Kurt was in a zone of error > > when > > > > clean, > > > > then as the VGs allowed for increased angle of > > > > attack, the error - lower > > > > reading - would be more pronounced." > > > > > > > > Yes I agree completely, just still can't see how > > we > > > > would necessarily > > > > recognize this with the data presented alone- > > > > without an external > > > > validation- IF we slipped into that error range > > > > where the AOA was > > > > sufficiently different (between the before & > > after > > > > scenario) to introduce an > > > > error of any significance. While I don't know > > > > conclusively, I strongly > > > > suspect that this remains a merely theoretical > > issue > > > > which does not come > > > > into play here at all. This, of course, would be > > a > > > > very good thing. :-) I > > > > agree that Kurt has done an outstanding job with > > > > this project, and believe > > > > his conclusion to be valid. > > > > > > > > I've beat this horse more than enough now. Hope > > I > > > > didn't ruffle any > > > > feathers- that certainly was not my intent. > > > > Personally, I found this to be a > > > > stimulating discussion. > > > > > > > > Stu > > > > > > > > > __________________________________ > > > Y! Messenger - Communicate in real time. Download > > now. > > > > > > > > > > > > > > Contributions > > any other > > Forums. > > > > http://www.matronics.com/chat > > > > http://www.matronics.com/subscription > > http://www.matronics.com/FAQ/Kitfox-List.htm > > http://www.matronics.com/archives > > http://www.matronics.com/photoshare > > > === message truncated === > > > _______________________________ > Declare Yourself - Register online to vote today! > http://vote.yahoo.com > > ________________________________ Message 12 ____________________________________ Time: 10:37:02 PM PST US From: kurt schrader Subject: Re: Kitfox-List: Barrel Rolls --> Kitfox-List message posted by: kurt schrader Darrel, No brave answers yet? When I did my parachute required stuff recently, I found my NSI engine mounts allowed a little too much movement and I got a scuffed cowl from the spinner. (I'm sure it was the spin to the left that did it) Might be good to check yours first. That heavy CAP prop makes a big gyro up front. I only have 42 hrs on the plane, but the engine has been hung for a few years, if that makes a difference. Do you have a G meter? I don't, so I limited my maneuvers to just one or 2 of each. I preceeded the maneuvers with 60 degree AOB turns to get a 2 G feel. I didn't do any barrel rolls. Not enough KitFox experience or attempts at each maneuver to suggest good data except: It should roll right better due to torque, but it rolls fine left too. I tried standard rolls starting at 100 knots. That was more than the Fox needed. I used 10 degrees nose up for the entry, but didn't get close enough to zero G's on entry and went a bit nose low inverted. Other than that, my maneuvers were too sloppy to be a good model. If you have a G meter, try a split S first from near stall speed and see what your bottom speed is when using good G control. That would probably do for a loop entry speed. It is important to set 1 G and increasing as soon as you are inverted to keep it tight and the speed down. If you don't get a good pull right off inverted or at the top of a loop, you'll overspeed. The cure for that is to recognize it early and roll upright before you get to 45 degrees nose low Cuban 8 style. Then try again. What works for a Citabra probably works for a KF, except you may roll better. Without a G meter, I am not anticipating doing any more acro, except maybe rolls and F-16 approach turns, which are way less than split S's. My fun meter is pegged for awhile. Kurt S. S-5/NSI turbo --- Fox5flyer wrote: > Anybody out there done barrel rolls with their Fox? > I need the step by step procedure including entry > speed. My prop is geared so is counter rotating. > Does this mean the rolls need to be to the right? > How about loops? > And yes, I'm getting a checkout first. > Darrel > S5 _______________________________ Declare Yourself - Register online to vote today! http://vote.yahoo.com ________________________________ Message 13 ____________________________________ Time: 11:15:09 PM PST US From: kurt schrader Subject: Re: Kitfox-List: Landings in 49 States --> Kitfox-List message posted by: kurt schrader Hi Stan, Ah, a break in my marathon plane testing and modifying schedule. Yes I remember, and thanks for returning my glasses too. You have an excellent plane there. I am glad it serves you well. I hope mine can get tot he same condition. BTW, one of my Rans friends says that the 100 hp Rotax is having a lot of heating problems on their planes. Haven't heard of that much trouble here. Oh, I would like to go to Alaska next year. It would be something, but I am already scheduling vacation time for next year and it is hard to readajust the schedule for such an event. If our contract got done and was good for retirement, I might just quit and go to Alaska that way. As it is, no end in sight for our negotiations. Some day I'll be a western mountain pilot and we can get together for more thrills out your way. Kurt S. --- SOURDOSTAN@aol.com wrote: > Kurt- > > I just came across this message from you and I don't > think I ever answered > you. Sorry!! > > You remembered my gear collapse and I hit my prop in > Alaska, but other than those two incidences, the > airplane and engine have been behaving flawlessly. > I sure can't say enough good about the Kitfox and the > Rotax engine. What a great combination!! > > I, too, think about the good time we had at > Sun'n'Fun last year. Hope to see > you again soon. How about going to Alaska next > summer??? > > I keep up with you through your postings. Looks > like you're enjoying your plane and working out some > bugs, and doing some experimenting. Keep up the > sharing with us - always something to learn from > what you do. > > All for now. Hope all is well with you. > > Regards, > Stan > > N16KC "Columbine" > Kitfox Model IV Speedster 912ul > Over 765 hours _______________________________ Declare Yourself - Register online to vote today! http://vote.yahoo.com ________________________________ Message 14 ____________________________________ Time: 11:18:53 PM PST US From: kurt schrader Subject: Re: Kitfox-List: Oil Tank Vent --> Kitfox-List message posted by: kurt schrader Clem, Is that miller straight or miller lite? I still need to install some material to hold back the oil better from blowing up my breather lines. I have the mess under control, but the oil blowby is a bit much. Maybe 1 cup per flight. Kurt S. --- Clem Nichols wrote: > Kurt: > > My oil tank breather is vented to a large Miller > High Life can. It works quite well, and makes an > interesting conversation piece. > > Clem Nichols > Do Not Archive __________________________________