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Jim Meade

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  1. If you buy foam, consider confor foam from either Wings & Wheels or Cumulus Soaring. This is what glider pilots use who may soar for 5-7 hours at a time.
  2. Changing rubber is probably partly based on the shelf life of rubber as a material, which beings at the cure date of manufacture. I've heard 10 years is the shelf life of rubber but don't have a reference to cite. What kind of condition inspection would one make on a rubber hose in a Rotax engine environment? The first issue is the fire sleeve which block easy visual inspection. If there are no visible leaks or other signs of problems after five years, I'd think one should disconnect one end of the hose and flex it to see if it is hard or brittle or still flexible. I'd think one should remove the fire-sleeve so one can inspect the hose to make sure the hose is not distended, worn, kinked, twisted, misshapen or otherwise not in a normal condition. Most are not likely to be eager to disconnect the hose and remove the fire sleeve, but how else does one perform a condition inspection if one can't visually inspect the outside of the hose for it's condition?
  3. Tom, Thanks for that reference. As I read it, the words recommend but do not require changing the screws in the existing units in the first place.
  4. From the SB, word for word: "Recent reports have suggested that there could be a problem with the new integrated thread-locker servo arm screws that have been sent out for retrofit by customers in the field." Apparently some users had reason to retrofit the servo arm screw and the new screw - the retrofit screw - would not stay tight in some cases. "Reports indicate that the screw could back out of its hole in the end of the servo shaft during normal usage." This is the new screw. "In speaking with the manufacturer of the new servo arm screws, the suspected cause is residual chemical thread-locker in the threads of the servo shaft which was the previous method for locking the arm screws in place." The old screw used thread locker such as loctite and when the old screw was removed and the new (retrofit) screw installed the residual thread locker didn't always permit a tight fit so that the new screw could work out. "While there are only a very few reports of this actually happening, Trutrak Flight Systems wants to take steps against the possibility of this happening. We will include the bracket shown below with all new servos shipped with the current servo arm screw. This bracket will also be available to all customers with the current servo arm screw configuration as a field retrofit solution." TruTrak changed to a shaft with threads that used a nut to hold the arm or capstan, but for those servos with the existing screw hole the bracket was offered to insure the residual thread locker in the screw hole didn't prevent the new screw from securing the arm. Mid-Continent says they have no parts or procedures for changing the capstan servo. They have brackets for the arm servos. My take on this is that one inspect the servo periodically and make sure the screw is not backing out. Maybe some witness paint is advisable so any rotation is easy to see. If the screw doesn't move, this is a case of nothing is broke so don't fix it. If you have reason to take that screw out then you are well advised to go to MCICO and get the bracket arm and install it per the SB.
  5. I just talked with Bruce Grammon, Technical Sales Rep of Mid-Continent Instruments and Avionics, the company that provides TruTrak service and support for Bendix King. He sent me a copy of the SB which I shared with Arian Foldan of FD USA and with Tom Baker. As the SB reads, the problem was a retrofit screw working out. Since these servos never had a retrofit screw, I don't believe the SB applies. The only reading that makes sense is that some people had occasion to change the arm or capstan, that the new screw worked out in some cases, and this bracket addresses that problem. The screws in my servos have never been removed and show no signs of backing out. Grammon said MCICO has the brackets for the arms for the C servo, the one with the arm, but does not have any parts or procedures for addressing a problem with the B-TOR capstan servo. TruTrak Servo Service Bulletin 060810 (1).pdf
  6. Thanks for pointing that out, Tom. I hadn't heard. I'll have to do some research. When you say the roll servo would need a modification, would it need it for a capstan as was used on the CTSW, or only if one puts an arm on it? If you have the clip let me know. In the meantime I'll check out the SB and see what TruTrak has to say.
  7. DigiFlight IIVS FP auto pilot head Part Number DIIVS-FP Serial Number 109881. Manufacturer's inspection date is 2-23-07. Basic Servo C Part Number DSS-C Serial Number 210213. Inspection date 3-7-07. Missing one screw on limiting arm. Basic Servo B TOR Part Number DSB-B TOR Serial Number 208720 no inspection sticker or build date. Designed for use with capstan which is not included. Mounting screws for the head are included. The servos are tapped for four AN3 or 10x32 mounting screws, not included. It worked fully when removed. More photos available if desired. There is an SB on the servos. It says if the screw has been removed to install a bracket on the -C or arm servo and to send the capstan servo back for factory modification. The screw has never been removed from the arm servo so it is not subject to the SB. The screw was removed on the capstan servo so it is subject to the SB. According to Mid-Continent Instruments, arm brackets are avaialbe for the arm servo but there is no procedure or method of modifying the capstan servo. These items are sold as is with the understanding that securing the screw in the capstan servo is up to the buyer. $500 include UPS ground in US up to $30.
  8. I have a TruTrak DigiFlight IIVS FP with two servos I'm going to advertise for sale. They came out of my 2007 CTSW when I upgraded to a Dynon panel, and they worked when they were removed. See For Sale forum for details.
  9. I agree 100%. It is incumbent on an owner-mechanic to accept responsibility for maintenance.
  10. This discussion has been going on since this site and it's predecessors have existed and will continue after we're gone. Here are a few of the main themes. You may add more. Some of it is true of other enterprises in life as well. 1. Mechanics and companies are worried about liability and everything they say has that as a factor. CYA. Owners know that mechanics have this bias. 2. Mechanics do not trust owners to understand or apply maintaining on condition - mechanics confuse it with the operator waiting for something to break and then fix it. Because mechanics have seen some poor owner maintenance they fear all of it will be so. 3. Mechanics develop a body of experience and based on that establish a perspective that informs their opinion in their field. When you walk in, they put you in a mold. 4. Owners resent being forced by some arbitrary condition such as time to spend good money to replace a good part. Owners feel ripped off and taken advantage of. 5 Mechanics say you need a guru or school. Rotax manuals are not current or sufficient. Owners ask how is it that the manual is insufficient? There are excellent tutorials online these days. 6. Rotax knows best. So does Boeing, General Motors, Corvair, Firestone, Dodge Caravan and on and on. Knowing best and admitting it and being willing to do anything about it are two different things. 7. Mechanics who worked on standard certificated airplanes developed a reputation for insisting on maintenance that has proven to not be required. ELSA is attractive because one does not feel at the mercy of some mechanic saying, "because I said so" . You probably identified other themes in this discussion, equally or more valid. This issue will never be resolved because it is not in the interest of the parties involved to settle it. It starts because everyone brings their own perspective to the problem. By perspective I mean bias, and I do not mean bias in a negative way. I mean, simply, what you see depends on where you stand. Oh, I'm an ELSA guy. I've been to the three Rotax classes and they provided good practice on things I could already do, like pull a piston or torque a bolt. Not one time was I told anything that was not in the manual. Not once. I have two good friends with ELSA who have a lot mechanical background and they are excellent Rotax mechanics at the Line level just by using the manual and asking individual questions of mechanics they respect.
  11. My introduction to Mt. Hood was about 1978 or so in a long-nosed Peterbilt with a 1693 Cat engine (this means no Jake brake) and 13 speed RoadRanger transmission. I approached from the south or east or wherever and started down to the west at 50 mph and soon came to regret that speed. Trying to be careful with the brakes I still got them smoking. I finally got to a pull-off with lots of smoke from the trailer brakes. When this happens, you need to try to let the brakes off to cool so they don't cool egg-shaped due to pressure from the drums when they are so hot. If you have to use brakes, alternate between tractor and trailer about every 15 minutes and give the wheels a 1/4 turn each time so they have a chance to get the pressure distributed over time. When I got to the bottom I found I had one cracked brake drum and two that got so hot they needed work. Not my best day running the mountains. I've run nearly all the passes except Wolf Creek but my first trip down Hood, while it should have been no big deal, remains a sharp memory because of my ignorance of how to run it with no Jake brake. Sorry for the distraction, some old memories are pretty strong.
  12. BTW, top the OP, I think everything on the maintenance schedule should be given due consideration. I do not advocate ignoring the existence of an entry. That does not mean I believe it is necessary or appropriate to do everything on the maintenance schedule as written. I also believe we should, as considerations indicate, include more items than are on the maintenance schedule or at an earlier or more frequent time than scheduled. This is based on the same reasoning that has us changing oil and air filters more often if we drive our Jeep in dusty conditions often.
  13. Preventive maintenance includes the concept of condition based maintenance. Condition based maintenance is not part of corrective maintenance. Corrective maintenance means fixing something that is defective and none of us proposes letting a component become defective before repairing it. Corrective maintenance includes the concept that the risk of failure is acceptable and the consequences manageable. That is seldom the case in aviation. One does not wait for an oil hose to fail, rather, one notes that it is getting soft, discolored, distended, collapsing or has other indication which shows the hose is less able to perform it's function than deemed acceptable and the risk of failure is increasing and at some point the risk is deemed unacceptable. This is the same concept where a person changes tires not based on time but based on the tread reaching the wear bars. You don't have to change tires then but most of us would agree it is prudent. I have wagon tires that are 25 years old. We might also change tires based on checking, uneven wear, out-of-balance or other indications of condition even though tire is still working. I have a glider that called for the tires to be changed at 250 operating hours although the tires appeared to be brand new. This is an example of where tire wear has little to do with how many hours the glider flew. Many gliders fly for 3-6 hours on one flight. Some fly 250 hours in 2 years and some may take 10 years. Some may land on grass. It's difficult for me to understand how operating hours has anything to do with tire safety. There was no reference to the number of landings or to the total life of the tire. Preventative maintenance includes condition based maintenance and does not include the concept of operating until failure or until an unacceptable risk of failure.
  14. I attended one of Mike Busch's weekend seminars in Rapid City, SD a dozen or so years ago. I talked with him there and several times since, and I've followed many of his webinars and sat-in on several of his Oshkosh presentations, so to me, Mike Busch is not some unknown guy on the internet. I've meet Tom Baker, the Gutmans, Adrain Foldan and Tom Peghiny, and Brian and Carol Carpenter and perhaps because of that have a pretty high confidence level in the competence of these people. Other internet gurus not so much. So, saying internet guru may be a question of perspective. Mike Busch spends a considerable amount of his time explaining how engines work and how mechanics misunderstand that and develop ideas and shop practices that are not substantiated either by science or the regs, but rather by the mechanic's own preferences and comfort zone. The lean-of-peak practices are one example of where engine manufacturers take a position that is not consistent with known, demonstrable facts. Charles Lindbergh can teach how to get more range from a P-38 by LOP and be a hero, while George Braly can show how to get better engine performance and life using the same methods and be sneered at by Lycoming. As Roger points out, liability seems to be a big issue with manufacturers and mechanics. It is reasonable to assume that some positions taken by both have one eye on liability as well as one on airworthiness. That can make the owner wonder if there is a conflict of interest on the part of the "expert". As Busch points out, airlines and the military maintain airplanes based on a different set of premises than time. Those institutions appear to use a philosophy based more on condition. It is strange that what is the rule for airlines and the military is frowned on in general aviation. Rotax has a rotten reputation for standing behind warranty and for the ways they distance themselves from US courts and legal remedies. Maybe now that the Chinese are building a copy-cat engine Rotax will have to face competition for the first time and may be less rigid in their policies. AMST and the FAA have different approaches to maintenance. Tom Baker will correct me if I'm wrong, but my understanding is an oil hose on a Taylorcraft can be inspected on condition while the identical hose on a Rotax sold on a European LSA is maintained on a time line. Bottom line - the main reason my airplanes are all ELSA is that I can legally, and I believe competently, maintain them with considerable more flexibility than if they were SLSA.
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