Jump to content


Popular Content

Showing content with the highest reputation since 06/23/2010 in all areas

  1. 4 points
    I bought my 07 CTSW almost 3 years ago not knowing anything about LSA airplanes. Turns out to be the best num nuts purchase I’ve ever made! This forum has made the difference between a bad experience and an awesome one! Thanks everyone!
  2. 4 points
    My best photo from yesterday's shoot is one of 'my' airport - Mammoth Yosemite Airport at sunrise KMMH
  3. 3 points
    I just got my new GoPro Hero 7, so I went out on a flight with some friends on a tour of the local grass strips. My buddies are in a Blue/White Avid Flyer and a Yellow Legend Cub, if you see them in the videos. You'll notice I use a lot of slips to manage descent rate (sorry that puts my noggin in the way sometimes), and on grass I always use 30° flaps unless the wind is just howling. BTW my airplane has the small roller skate wheels/tires, and I did all these landings with the wheel pants installed. You guys with Tundra wheels have no excuses to not be landing on grass, and you are missing out on a lot of fun if you don't. My CT can land at 90% of the places the Legend Cub can, it's a pretty good short field airplane for what it is. First up is Aerie (1GA9). My friend with the Legend Cub owns this strip, and it's kind of our "base of operations" when our group gets together to fly. The runway is 2000ft and very smooth and well mowed. My landing is to the North over the trees. The South approach is a little easier, though not as much fun. 😎 Landing sequence starts about 1:45 into the video: Next up is Taylor Field (GA16). Owned by Larry Taylor, an 80 year old super-nice guy who still flies the same J3 Cub he's owned since 1974. The runway is 2100x50ft with the preferred landing uphhill. There is a pronounced hump in the runway right around where you would touchdown, so ideally you try to get down fast and land on the up slope of the hump. In this landing I was a little long and landed just past the crest on the down slope, which is also fine. What you *don't* want is to touch down on the crest of the hill, as you'll be back in the air on the backside with no energy and you'll put your gear in danger if you don't add power immediately. Grass was in need of a mow yesterday, but not out of control. Landing sequence starts at about 55 seconds in: Third on the hit parade is Southern Oaks (GE35). this is the shortest field in the series, at 1400x60 feet. But the landing is uphill and the approach is clear for a long way out, so it's actually a very easy place to land if your speed control is good. When we landed there yesterday the owner had just fertilized, so you could smell chicken shit a mile out from the runway... 🦆 Landing sequence starts at 1:55 in the video: Last is Sleepy Hollow (GA18). This is a neat spot owned by the son of a very successful real estate developer who flies his Aviat Husky from there. It's 2600ft and has runways that are parallel grass (60ft wide) and concrete (22ft wide), and an easy place to land in either direction. In the video my buddy lands ahead of me in the grass and I land in the pavement. I almost forgot to turn on the camera, so the landing sequence starts right as the video starts: Those are the four grass strips I most commonly land at. There are a bunch of others we go to occasionally, I will get some videos of them as we hit them going forward. I also have takeoff videos from all these spots except for Sleepy Hollow; if anybody wants to see those I can put them on YouTube.
  4. 3 points
    We had a "good day" window here in Connecticut between snow storms. I felt confident enough to take my 20 yo son up to the famous Sky Acres airport restaurant in NY State (44N) as my first pasenger . Sky Acres is a 70 ish mile trip from home. My in-shape son and his out of shape Dad filled the tanks up to 1,250 GW... the most weight I had experienced in the CT before without a CFI. We still climbed out at an honest 800 fpm and I wasn't trying. It was a bit breezy, mostly just a glancing cross wind down the runway so I decided to land at zero flaps. Final was too fast because I came in too high but managed to get it on the ground in time for the first turn off. Had a great breakfast and quickly got back in the plane for the flight back as the clouds on the horizon looked a tad on the dark side... Getting licensed again and buying the plane were fun... but there is nothing in this world more awesome than taking a family member up flying to "get breakfast". A milestone I have been dreaming about for years... I admire the young pilot/Dads and Moms who are taking their young children on flying adventures... nothing beats it. Fly safely everyone, Andrew
  5. 3 points
    This trip was just way too awesome, i had to share some photos. Kites and kiteboard all ready to go.
  6. 3 points
    Just a quick flight to this beautiful volcano. Lovin the CT to fly up here.
  7. 3 points
    I am planning to attend with my wife. We will be flying our Sting S4 and it will be the first time for us. October is kind of long way off but that’s the current plan.
  8. 3 points
  9. 3 points
    Yep, Buckaroo that’s mine! They buffed out the white and there is NO difference in the areas that had the old decals. So happy with the results and Flight Design USA’s Tom and Arian.
  10. 3 points
    Installed my e-prop and completed 4 test flights at different wot rpm's on ctsw. The manufacturer of this prop recommends 5500 rpm wot as the overall best rpm for all flight parameters for the 912. The blades have a much smaller chord than any I have ever seen. I tried 5650, 5600, and 5500 with all variables the same, ( oat, baro, altitude, clean blades, 1/2 fuel, etc ). My original prop was a 3 blade Neuform and was flown just prior to the e-prop for comparison. 5650 and 5600 numbers were ok but the 5500 numbers were much better. Climb rpm now is 5300 at 1300-1400 ft/min, as opposed to 5000 rpm and 1100-1200 ft/min (less load on engine in climb). Cruise at 5400 is 115-116kts, at 5200 I get what I used to with the Neuform at 5400. Takeoff distance is much shorter( less than 6 kts wind today). A major difference for me is much less vibration, I used to get vibration when transitioning from cruise to reduced power settings in a descent until stabilized (I have heard others complain about this). Now I get no vibration. The prop also stops much easier due to being much lighter in weight. In evaluating this prop I tried not to split hairs, even with turbulence today. To me I had obvious performance increases but I am sure others will have to do their own evaluations, pilots and planes are all different.
  11. 3 points
    A couple of things: 1) My engine mount isolators appeared cracked for *years*. I deferred the maintenance because I wanted to do the Rotax rubber/hose replacement at the same time I replaced the isolators. When I actually did pull them out, only the very outer visible edges were cracked, the part of the isolator that is important, where it holds the bolt, was perfectly fine. I think the outer edges where the isolators get bulged and stretched are prone to cracking, especially since they are subjected to direct engine heat. I don't think that necessarily means they are going bad. In fact, my new isolators (less than six months on them) already have tiny cracks in places, in spite of me treating them with silicone grease as recommended by Roger. I'm not concerned. If you can rub them and pieces flake off, they are probably in trouble. Otherwise I'm guessing they are still serviceable. 2) Getting to the isolators means pulling the engine. It's not that hard to do, but it does take some time. An engine hoist makes it much easier. You only have to pull it out about 6-12 inches from the firewall. But honestly, if you have a rubber replacement coming up in the next couple of years, I'd defer it until then if you mechanic will agree to it and your mounts are not getting flaky as mentioned above.
  12. 3 points
    Five years after laying down lots of money it looks as if our two planes for AUS have finally been shipped. GRYPHON (CTLS jubilee) and I (CTLS turbo) have some bill of loading info. to suggest that our planes will be in Melbourne AUS in the third week of October. Just after I get back from Page. This has been a long saga with countless stories lies and promises from Germany. Our agent has paid many thousands of euros extra for each, we have paid the freight and insurance twice, I sold my beloved CTSW a couple of years ago on the promise of delivery, the stress feels like it never ends. And now on the water are our two new bundles of joy, is this a dream ? no it is real !!! finally. Will post again when we know more. PS others may of may not be all that interested but it makes me feel pretty good to be actually able to post this.
  13. 3 points
    I suggest some look at this differently. The user "Safety Officer" took the time to make a pretty extensive post full of information. Instead of saying "thanks" or perhaps critiquing anything in the post, you crap all over it because you don't know the user's real name. Then, the logic becomes that the post is bad data because you don't know the user's name. To put it politely, that's absolutely foolish. There have been plenty of times well known "names" give bad advise. Name or no name make no difference as to the value of said advise. Having a title or no title doesn't makes no difference. If you feel otherwise, you're bound to be fooled. So, does anyone have anything to say about the actual post by S.O.? Does anyone agree with the content he/she posted (for free)? Or does anyone have a critique of the content?
  14. 3 points
    That is the choice of a poster. The credibility of a poster is determined by their historical posts, not their name. I think Safety Officer's posts speak for themselves.
  15. 3 points
    So far, so Good! I personally like the new system, especially the "Activity, all Activity" view. In fact, I've saved an icon that takes me to that spot as my normal way to get into the forum. I've turned on a new feature.... the "Like or Dislike" reaction, similar to Facebook and Youtube. It'll help us track content. Be kind and let's keep things civil.
  16. 2 points
    Lots of people make fun of the egg or refer to a flying sperm .. but CT planes do have a character... but this one just doesn’t look look that great ...
  17. 2 points
    No wonder the CTSW is lighter! 😜
  18. 2 points
    I was very fortunate. One of my worst days somehow turned into one of my best??? The mission to replace my beloved but somewhat beat to death CTSW is going well. Expecting to be back in the air in 3-4 weeks.
  19. 2 points
    I went with a GTX 345 for in and out. Replaced my 396 with an Aera 660 for the display. I would have liked a larger display but the 660 fits in the same panel space as the 396.
  20. 2 points
    That would be nice but I have already found the perfect plane for me. Its a CTSW with no loan payment. A very important feature.
  21. 2 points
    it does, another CTSW. I still prefer low wings and want more speed but the CTSW checks more boxes than anything else.
  22. 2 points
    With the left tank still empty, open the gascolator drain and see if you get normal fuel flow. If not, you have something wrong in the fuel path from the right tank to the engine -- pinched hose, debris in the hose, clogged wing root strainer -- something. If you're already put fuel in the left tank, open the gascolator drain and drain the fuel back into your gas cans. If you only see the fuel level going down in the left tank, keep draining until all the fuel is gone from the left. If the fuel then stops and there is still fuel in the right, again you have a right side fuel path issue.
  23. 2 points
    Actually, they are dirt cheap with respect to the amount of development hours invested divided by the number sold... in fact, the project is in reality a labor of love. R&D is hugely expensive. My hat's off to you Skunk for creating/making them. I am waiting to see what they look like installed. I will buy a pair too if they are what I think they are.
  24. 2 points
    It was a sign shop that did the work. They do mostly cars and vans. Came out absolutely perfect. I had them do the N-numbers black with a silver shadow to match the scheme. Really like how that turned out.
  25. 2 points
    Slips do not require a "nose up attitude". With 30° flaps the attitude in a landing slip is quite nose low, even down to 45kt. You do have to hold the nose up a bit to avoid picking up speed, but not to anywhere near a nose high attitude (which I would consider above the horizon, maybe you mean something different). IMO, 50kt is too slow for a 15° flaps approach. It can be done, but you are going to have an "impressive" sink rate that must be arrested before touchdown. If you miss-time the roundout too early, you can be out of energy and in for a "carrier style" landing. Too late and you sink through ground effect for the same result. My 15° calm wind approaches don't generally get slower than 55kt, maybe 52kt if wind is dead calm. If I want to land slower than that, and/or land on a short runway I will use 30° flaps.
  26. 2 points
    Cleaned up and zoomin for the stars (is how I roll )
  27. 2 points
  28. 2 points
    Ladies and Gentlemen, May I catch the chance of this message to wish all of you height, interesting perspectives, and nice flights for this new year and the many years to come. May 2019 offer you everything nice you deserve. My wishes go to you fellow pilots, as well as your families and all those who are Dear to you. Happy New Year.
  29. 2 points
    What's amazing in these photos is the way they bring out differences in color. I don't remember seeing the pattern in the rock shown in the last photo when I was there. The second to the last photo would be very helpful in route selection. The last photo… not so much. You need a closer view. The last photo is the back side of Humphreys. I first saw this, and attempted to scale it, during a week-long, solo backpacking loop. I quickly recognized that it was a technical climb and gave up. It's heartening to realize, 50 years later, that I wasn't completely stupid. That was late summer. I came back on Thanksgiving with a huge group of family and friends (14?). It was foolhardy. The average competence level was exceedingly low. We didn't make it far. I came back again a couple months later to attempt a winter ascent with a proper climbing party. We sleep in the middle of a frozen lake just off to the right (south) of this photo. (I have not done that again. The ice creaks and groins all night, keeping you awake.) Our summit attempt the next morning, up the middle of the face in the last photo, did not go well. There were a lot of pitches. We were going too slow. Then our lead climber dropped a glove. There was no way to recover it, and no way to continue without it. (Ever since then he has tied his gloves to a cord running up his sleeves and over his shoulders.) I came back again the next summer and successfully soloed the peak via the southwest ridge (on the left in the second to last photo). Most of the route was class 3 scrambling. Only the summit block was class 4 or low 5. The summit block is the highest knob on the right side of the peak in that second to last photo (It’s on the left in the photo of the back side). It looks like a tiny step in the photo, but it’s actually a bit tricky getting up. I developed a solo rope system, on the spot, which worked well for me on a number of subsequent climbs, including class 5.7 peaks. I made two subsequent attempts on southwest ridge with my climbing friends, the last of which was also successful. Mike Koerner
  30. 2 points
    Yes. The 861-188 is the newest version of floats for the 912's and 914 engine.
  31. 2 points
    Page fly in 2018 update. So far 5 planes. Starting on the right, we have Larry Jefts. He came the farthest (Honolulu, HI) and has the oldest plane here (1969) Cessna 172 K Then Carol Swenson. She drove the farthest _Friday Harbor Washington to Page (with Darryl's tug for his Diamond 40) At the far end, Darryl Swenson, What a beautiful new Diamond 40 Diesel he showed up with. He easily gets newest plane and concorse de elegance. Then Jan Kreienkamp who came in with Hubby Ron. Ron took his CTLSi experimental and looks slim and trim this year. Then on the far left we have Mike "Mikey70" from Rogers, Arkansas on the web site. His first time so he is the newbee and fits right in. Next is Christine and Lee Bergmann. They were voted the youngest/best looking, couple here. There was only one vote and that was Lee. Last is me, Duane Jefts. My job is to keep Larry on the straight and narrow.
  32. 2 points
    To answer your original question - No - a larger tube does not eliminate the need for a carb balance. I still balance my carbs at annual, and usually check it one other time during the year, if needed. I've had my rotax for three years now, and once I got it balanced, I really never have had an significant unbalance issue. Knock on wood I guess. The larger tube is acting like a dynamic absorber between the carbs at low rpm's. It is absorbing pressure pulses between the cylinders at low speed. As noted, above 3000 rpm, the larger crossover tube has no effect. The really nice part of the larger tube is that you can now idle your engine down to about 1350 or 1400 with no shake rattle, n roll. And, if you install the larger crossover tube, don't let anyone tell you it will tear your gearbox apart. I have measured the vibration coming from the gearbox at 1350 rpm and it is .08 inches/second velocity - which is excellent! My engine currently is balanced to .03 in/sec at 5350 rpm, which is where I cruise. As to the reason that Rotax doesn't change the crossover tube - who knows - believe it or not, that just may not be a significant issue for them. The simple fix is to tell all of us to idle at 1800-2000 rpm, and it kinda goes away. Problem solved. No cost to Rotax. I have sat in engineering meetings where a supposed expert convinced our lead engineer to perform a certain procedure . Several of us on the staff tried to convince him not to do this, but our lead engineer had a rather enlarged ego. It ended up costing our company in excess of $300,000.00. No kidding. Look, these engineers are just people like you and me. Some really are smart, but some are incredibly dumb too. They should have stayed at the university and taught. LOL How many automotive recalls have you read about in your life?? Hey - those vehicles were built by engineers. I'm not down on people who decide to become engineers. But, please, they are not infallible. And just because Rotax did not put a larger crossover tube on the engine does not mean that it coulld not benefit from one. Sorry for the long post - I really hope this does address your original question. Regards Rodney
  33. 2 points
    We are getting close to the deadline. What is the solution for the CTLS? UAvionix on the wingtip won't work and now I have found out that the taillight unit won't work either. Apparently the carbon fibre blocks the wing tip version and makes it unreliable. I tried to install the tail version and the mounting holes are different. The taillight on the CTLS uses angled mounting holes and are further apart than the UAvionix unit. The unit needs to be mounted with the fin on it vertical and using the mounting holes would have it a about a 41 degree angle. They have no plans on revising the mounting bracket to make it work. I have one I was going to test for them but now I need to start looking at something else.
  34. 2 points
    Here's an attempt with the 14,000'+ White Mountains in the foreground
  35. 2 points
    RPM no, there's no direct relationship. Throttle yes, though. It's about the air mass moving through the venturi, the air pressure under the diaphragm, the vacuum above it (dictated by air moving through the venturi), and the piston spring trying to hold the piston closed. The needles have a taper to them. There's a point after which the piston is fully retracted, and the fuel limitation is no longer the needle, but the diameter of the jet. This is the "full rich" mode and will supply much more fuel than the engine actually needs. If you were to change the jet diameter, you could lean or enrichen the full power setting (not recommended, just saying this is how they do it in motorcycles that use these same carbs). At high altitudes though, there might not be enough of an air pressure delta to lift the piston against the spring. So you'll never actually see full rich.
  36. 2 points
    This is a photo of Mammoth Lakes California taken this morning from about 11,000' The SW flow is 40kts from left to right. Notice the smooth contours of the clouds on the left but after colliding with Mammoth Mountain in the center the flow on the right is now disturbed and no longer smooth. The air here is smooth in places and turbulent in others as this visual shows.
  37. 2 points
    YEAH !! I am still waiting for him (Roger) to take a trip to the Philippines and work on my aircraft
  38. 2 points
    I might regret posting this but when I read people say that a CT lands flat I think that is because the speed is too high. Slow it down a bit increase the angle of attack the nose wheel is now higher. I can see why some are scared of full flap landings because it is a little more demanding but that is a matter of practice. The stall is so docile and also low speed that it is not to be feared. Get out there and enjoy such a wonderful capable bird.
  39. 2 points
    When operating at low throttle the mixture is lean anyway then add very cold air and the mixture is very lean. Carbs will altitude compensate but not density compensate like injection will. The answer is to just increase throttle till it smooths out or if you don't feel like that just go higher for thinner air which will also fix it. The altitude compensation of Bing carbs is not that good anyway so climb to find the best spot.
  40. 2 points
    Amelia Earhart Peak 11,974'
  41. 2 points
    I never really liked the Willette opinion letter. It focuses on part 43. That portion of the regs. imposes NOTHING on owners or operators. The topic of mandatory engine overhaul, or any other mandatory maintenance, are requirements of WHEN to perform maintenance, and they are found in other rules like part 91, 39, 135, etc........................Part 43 speaks to WHO can perform, and HOW maintenance must be performed. So for SLSA, 91.327 is the operational rule that puts maintenance burdens on operators. It doesn't speak to any kind of "maintenance program". It does speak to an "inspection program" for the aircraft.......................................... a "Condition Inspection". A condition inspection is just that..........................an inspection. That is the extent of legally required maintenance on SLSA aircraft. The other key language in 91.327 is the requirement for operators to have any maintenance performed on their SLSA be performed (by appropriately qualified personnel) in accordance with PROCEDURES. In the case of SLSA, these PROCEDURES must be those specified by the aircraft manufacturer. An overhaul requirement, or a hose change requirement, or a training requirement, are not PROCEDURES, and are therefore not part of required maintenance on SLSA regardless of what the maintenance manual or POH say. I agree with previous posts, that an SLSA aircraft manufacturer can make other types of maintenance legally mandatory with regard to WHEN, and HOW by way of the Safety Directive system. The FAA can also do so using the Airworthiness Directive system. I too think that the inspector in IOWA is 100% wrong in taking the position that the engine must be overhauled for the aircraft to be legal. He is well within his authority to say that he is not going to certify the aircraft as in a condition for safe operation, but his basis for saying it is fundamentally incorrect in this case. Same could be said for hose change, or lock nut change. Absent a Safety Directive or AD, those types of maintenance requirements come down to the judgment of the inspector after diligent application of the required inspection PROCEDURES. Just because something is replaced, or overhauled does not by itself correct an unsafe condition. I can replace a properly functioning used lock nut with a brand new defective one, and I have actually induced a potentially unsafe condition. Wouldn't it just make more sense to use proper maintenance PROCEDURES when installing/inspecting any fastener, and then safety can be assured. Basically what that means is......................if the nut is found to be bad as installed, REPLACE it. Used is not necessarily bad, new is not necessarily good...................Judgment prevails and the regulations support this. How many hose changes have resulted in off airport landings due to debris? How many off airport landings have been found to be a direct result of NOT replacing all hoses at and arbitrary 5 yr. mark? Anticept, The Piper hose AD is an apples to oranges comparison as I see it. The unsafe condition there is cause primarily by a routing proximity to the aircraft exhaust and not a blanket life limit for a hose. It is very specific, and as we have discussed previously, the AD only applies to aircraft with a specific type of hose design installed in the first place. Nevertheless, the safety issue was addressed in the correct way. If hose changes or engine overhauls, or locknut replacements are so critical to safety in the SLSA world, a Safety Directive must be issued.
  42. 2 points
    The latest is that our two are on the docks in Singapore. They were offloaded from the TAURUS on the 4th Oct. and scheduled to load on another ship end of month. That would have them arrive in Aus. fifteen days later. We wait patiently but at least they are out of Germany.
  43. 2 points
    Thank you John Olaf and Tim for organizing such a great fly-in. Thanks also to tour guide extraordinaire Dwayne for a wonderful tour of Bryce Canyon and all the helpful tips regarding places to fly and things to see during our short stay in Page. There are not enough superlatives to describe the flying and the scenery in the area, we only wish it was just a little closer. We landed back at KYIP shortly after 2:30 local time Monday afternoon. Long day Sunday to Kansas City, MO but we did have good weather all the way home, just not the tailwinds we had hoped for. Including the three days of amazing flying in Page, we put 38 hours flight time on our CT, averaging just under 5.2 gallons/hour. Again, thanks to everyone for a fantastic time. Incredible flying and wonderful people - it just doesn't get any better!
  44. 2 points
    I am in the same position as GRYPHON and I thought about flying my new aircraft home to Aus. from Germany. The promises that keep coming all the time like "it will be packed in the container next week" and so on keep us hoping that it will happen soon. The logistics of getting the necessary permits and clearances are significant and time consuming. The other main problem for me is that my family believe that I would be shot down over Pakistan or some other hostile unstable country or if I made it to Indonesia get locked up or held for ransom. Still trying to hold a sense of humour.
  45. 2 points
    My next bird will have the 3rd wheel in the back. Can't beat them off airport. I've taken mind into some fairly rough ridge tops, fields, etc. and thankfully it's held up with the custom fork and gear extensions / big tire setup I built. Mostly it's due to Randy designing a tough plane with a solid nose wheel design. But either way it's harder on it than a tailwheel. We also get horrendous wind here in CO near the rockies, so one has to make peace with the possibility there will be a few days a guy will want/have to sit out. I mean you can land in 50-100ft if you have some wind so setting it down across my runway isn't out of the question, but you still have to taxi in that crap! I see it as they are capable of 'more' (more-rougher surfaces, so more LZ's, more speed, more torn up gear and wings etc.! ) But it really depends on the plane too. Something you can touch down slow in allows more option for landing into the wind. Then again my buddies helio courier is a real handful in fairly mild cross winds (~15mph direct). It touches down slow, but the mains are in front of the firewall! You can slide the wheels on pavement without it nosing over, but there is a lot of weight behind the wheels and ground looping comes easy. Plus you can't see anything out of it on 26's Does sound more like a technique issue and not so much of a lack of rudder authority issue in the x-wind though. Bummer
  46. 2 points
    They should have used beaded fittings. I think Flight Design is the first aircraft that I've seen use barbed fittings... everything else is either beaded for flexible, or flared rigid with a B-nut (AN818) and T sleeve (AN819).
  47. 2 points
    Vibration Common Causes and Fixes I get many phone calls on vibration in owner’s aircraft. Here we’ll talk about some of the common causes, where to look and what you can do to help mitigate these vibration issues. Here is a common list, but is not all inclusive; 1. Carbs not synced properly. 2. Carb vent hose improperly placed or removed. 3. Carbs not opening equally or fully. 4. Prop blades not the same pitch or out of track. 5. Prop out of balance. 6. Aircraft wheels not balanced. 7. Old rubber engine mounts. 8. Mag drop difference too wide between ignition modules. 9. Trigger coil air gaps too wide. 10. Gearbox worn, damaged or in need of maintenance. So let’s address each of these. The carb sync (#1) should be fairly obvious to most now. The carbs should be synced at each annual / 100 hour inspection or anytime they have been removed for maintenance or you suspect a problem like vibration and you need to rule this in or out as the problem. Carb sync is vital to a good smooth long lasting running engine. You don’t want one side trying to run at 5100 rpm while the other may be trying to run at 5200 rpm. Sync those carbs. Once done it’s easy to keep them there. The carb vent hose (#2) that may be attached to the standard Rotax air box, a small clear plastic tube on the side of the carb under the carb bowl bale or some others have them routed to different places. These hoses should be as close to equal length as possible and be routed to the same area of pressure. If one hose has fallen off the side of the carb and the other is still attached it will cause the carbs to become unbalanced which will cause your vibration. Do not place these hose ends in the air stream outside the cowl. These only take a minute to confirm their attachment and placement. Check to see if the carbs open equally (#3) by moving the throttle from idle to wide open when the engine is off. You may see some signs of this during a carb sync, but most people don’t go above 3500 rpm for a carb sync so you need to double check this while the engine is off to see if they do in fact reach WOT at the same time or if one hangs up slightly. The prop blades all too often are not the same pitch (#4) from blade to blade. This is easy to double check and can be done with either a prop protractor and or a 12” digital level. Measure back from each tip 8”- 9” and put a mark on each blade. Make the blade out to your right level with the floor and then put the level on the back of the blade where you made the line from the tip. The blades should be no more than one tenth of a degree out from each other. That measurement seems small, but it is quite easy to accomplish. The Sensenich prop gauge pins are not accurate enough. Check them by hand with a prop gauge or level once you are close. To check tracking place a box underneath the bottom tip of a blade pointing straight down. Put a line on the box where that tip just barely touches the box. Then swing the other blade(s) around and see if they all cross at the exact same mark. If they don’t you’ll need to loosen the prop flange bolts and re-torque them to get the blades to all track over your line on the box. Prop blades now days are much better in balance (#5) than they were decades ago, but all props should still be dynamically balanced. All wood blades in humid climates can change due to moisture absorption. With all the new composites that aren’t susceptible to this anymore I’m not a fan of all wood blades. Even the main bolts change torque with humidity changes. A dynamic balance will not only help vibration, but will help save your gearbox from wear or damage. The heavier the blades i.e. long Warp Drive props the more important this becomes. I have never found an aircraft wheel (#6) in balance. Most do not ever think about the smaller aircraft wheel being out of balance as a vibration cause, but over the years I have cured many a vibration just by balancing the wheels. I always balance all new wheels I install. I see some occasionally that would need up to 20 x ¼ oz. weights to bring them in balance. If you failed to balance your wheels you would never find this huge disparity. These come off and go back to the distributor. What I normally see is 2 – 8 x ¼ oz. weights per wheel. It usually takes me about 3-5 minutes to balance a wheel after it’s off the plane. Don’t disregard this when you are looking for a vibration cure. Old rubber engine mounts (#7) are a common problem. Rotax wants a 5 year rubber replacement which I’m a fan of. This includes the rubber engine mounts. Rubber can get hard or soft from repeated heating and cooling cycles plus chemical exposure and just the ozone in the air. I replace these every time I do a rubber replacement on an aircraft. It usually isn’t hard or expensive. The mag drop vibration (#8) should be obvious when you do your mag drop check. Most see anywhere from 40 rpm – 100 rpm as a normal drop and usually both mags are within about 10 rpm – 30 rpm of each other. If you experience 300-1000 rpm drop then it’s time to troubleshoot your ignition system. There are documents out there that tell you how and where to look for ignition issues. It could just be a bad plug, too wide a plug gap, a bad plug boot, a bad connection at the plug boot where the wire screws in. If it is a large drop like 800+ rpm it may be a bad ignition module. These are all items you need to rule in or out. Always start with the most common, easiest and cheapest first. Do not just throw money at everything hoping to hit the jackpot. Most ignition issues are simple common issues. The trigger coils (#9) in the flywheel compartment can at times have too wide an air gap between the pick-up and flywheel trigger point. These are checked by using a feeler gauge and checking the gap tolerances listed in the Heavy Maintenance manual and setting them to the proper gap. These can even be off from the factory so check them before installing a new engine when they are easy to get to. You not only are checking the gap, but the screw torque for tightness. Gearbox (#10) care is important. As you look for your vibration issue consider the gearbox. It has maintenance service times at either 600 or 1000 hours. Using an automotive oil over a motorcycle oil can cause premature wear and damage. At your 100 and annual inspections you should be doing a gearbox friction torque check. Normal measurements that I usually see in the field is between 425-490 in. lbs. There is a low limit, but I personally don’t like to see anything in the 300 in. lb. numbers. It only takes a few minutes to perform. Checking the magnetic oil plug for debris at every oil change is another check for gearbox wear and damage. Prop strikes should have the gearbox removed and sent to a distributor for a special inspection. Gearbox’s when taken care of tend to last a long time, but there have been a few with excessive wear in early run hours. There have been some with the 912iS engine. These are the 10 common causes for unwanted vibration. Most are easy to fix and find. When trouble shooting start with the cheapest and easiest to rule in or out and progress to the harder least common when you do your checks. Whatever you do be methodical and don’t jump all around to exotic areas to check. Most Rotax issues are easy to find when you start at “A” and then work to B, then C and so on. I hope this helps some reduce any frustration in locating an unwanted vibration. Signed your friendly, Safety Officer.
  48. 2 points
    I guess I don't get it, either. If you physically took your plane to a mechanic and he/she refused to provide a name and credentials, then I would agree with the hospital analogy. But this is an open internet forum -- nothing here is official, even if it comes from someone who does provide their name and certifications. As a newbie I have found the advice here invaluable, from many sources. When I did my first oil change, I printed out a post from Roger for reference. Roger provides his credentials, but I used the information because it was well-reasoned, made sense, and I from past forum use have a positive opinion of Roger's expertise. But could I use that information in any legal capacity; i.e. logbook entry or justification of method used? Of course not. Like most here I have also gotten plenty of good advice from "non-credentialed" posters. FredG, a few months ago you gave me some advice about flap use, which I found helpful. I used the advice despite the fact that you are anonymous and provide no credentials because it was logical and made sense and I had a good opinion of your previous posts. I can think of several scenarios where a poster might wish to remain anonymous, for reasons unrelated to the usefulness of the information. I would hate for that person to stop posting in response.
  49. 2 points
    I don't get it. Whats the difference between his name and yours? Or anyone's? I don't see a CV/Bio posted with your name or any other poster. Would you take advice from a poster with the name "RotaxGuru" with no posting history, or poor history? Or "JoeBlo" with 1,000 thoughtful, informative posts. In any case, you could always PM the person to discuss your questions or comments. What exact policy would make you happy? v
  50. 2 points
  • Create New...