X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-gx0-f172.google.com ([209.85.217.172] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3579827 for flyrotary@lancaironline.net; Mon, 13 Apr 2009 17:23:03 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.217.172; envelope-from=wdleonard@gmail.com Received: by gxk20 with SMTP id 20so8631gxk.19 for ; Mon, 13 Apr 2009 14:22:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=i9wbirQ8gA24rKxOmYJceXqGqQhbmP0E8W5nzkxap/E=; b=SlqwhDcUrpak5LwC0eIY0FUqeuUfW8sgMwsuvGw4Ll3FxVZrtRyNNyY0e3TX5v4WJb KW+M5e4R6acpy+buaXTxXfz2KalGEoNPMb6LcO8TQJ4WD7pdf4qTC273FZPruzuPyOL8 1YUb8tjTLx+jSggmnKw+CQLWOvPfbUjjDNmaA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=j+R/9Cb8vbuLDBQ43rCZz40if4glHdB0rp4u1+ywymzY/hwMmQ7ioYJPAU/PvMWisQ pBbJ7LYuQlc0+Q3S1F4t8yQxJdliA7AqMyz+VlahGZbX60UWDi/17Z++VUWvPH4+YRqP CRtBFos0wmfG1rK+sGzCLhurY4tgpVs0aEP6E= MIME-Version: 1.0 Received: by 10.90.106.4 with SMTP id e4mr2045598agc.78.1239657746990; Mon, 13 Apr 2009 14:22:26 -0700 (PDT) In-Reply-To: References: Date: Mon, 13 Apr 2009 14:22:25 -0700 Message-ID: <1c23473f0904131422i7f16cac4vb95876c16be4a210@mail.gmail.com> Subject: Re: [FlyRotary] Re: forced landings From: David Leonard To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0016e644cf32a724980467764f12 --0016e644cf32a724980467764f12 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Thats a good question. Probably a big espensive machine somewhere that I can't afford. I guess thats why mine pop off occasionally. --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Mon, Apr 13, 2009 at 2:17 PM, Bill Bradburry w= rote: > Dave=92s number 4 below brings up a question I have been pondering. > > > > How do you put a bead on the ends of aluminum tubing so the hose will not > slip off??? > > > > My tubing is inch and a quarter and probably 0.060 thick. Suggestions > appreciated. > > > > Thanks, > > Bill B > > > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *David Leonard > *Sent:* Monday, April 13, 2009 4:48 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: forced landings > > > > Mark, > > > > Thanks for putting together this database. I agree with you and Al G. th= at > we should keep it to issues with the engine and it's systems. But I also > agree with John and Al W. that we should somewhere include things that > probably would have caused an in-flight failure, especially when found on > pre-flight, run-up or take off roll. That is good stuff. Not the > idiot-pilot-owner stuff like forgetting to attach the return fuel line, b= ut > the alternator bracket and PSRU issues etc - that could really help someo= ne. > > > > Similarly, just because it is in flight does not make it newsworthy. Lik= e > the intake hose blow offs that John and I have both experienced. Sure, > something happened and you are damn sure going to return to the airport a= nd > check it out even though you are pretty sure you know what happened and i= t > will not affect the safety of flight. OOps, didn't tighten that hose tig= ht > enough. > > > > In other words, I think Johns incident #1 is far more significant than > incident #4. > > > > Maybe to clarify: > > > > #1 caused actual damage to the engine AND he NEEDED to land soon because = of > oil loss. Power produced was less than normally aspirated power. This i= s > an interesting mechanical possibility (that a turbine blade somehow got B= ACK > into the engine to bust the apex seal) and something important to conside= r > when designing a turbo install. > > > > #4 caused only a reduction to normally aspirated power and a skipped hear= t > beat or two. No damage, no real need to land other than as a precaution. > No design flaw or mechanical issue - just an underestimation on how tight= to > make the hose clamp. (and believe me, they have to be very tight if there= is > no bead under the hose.) > -- > David Leonard > > Turbo Rotary RV-6 N4VY > http://N4VY.RotaryRoster.net > http://RotaryRoster.net > > On Mon, Apr 13, 2009 at 6:16 AM, Mark Steitle wrote: > > Dave, > > > > I have decided to take Al's suggestion and limit the criteria for the > spreadsheet to basically include any in-flight system failure which > interrupts the planned flight and results in a premature landing. Based = on > this, I will add #3 & #4 as well as the one resulting from a ruptured > coolant hose. > > > > Mark S. > > On Mon, Apr 13, 2009 at 7:55 AM, David Leonard > wrote: > > Mark, And did you get these? Added by me and John Slade under the wrong > thread title: > > > On Sun, Apr 12, 2009 at 5:15 PM, John Slade > wrote: > > Here's a few for the list, Mark, > 1. Stock turbo bearings collapsed & took out apex seal. Flew home at > reduced power. > > 2. Fuel filer (sinstered bronze) looked clean but was restricting fuel > flow. Flew home on other tank. > > 3. Bad / intermittent contact on ignition timing sensor made engine run > rough. Landed normally and repaired. > > 4. Turbo hose blew off on take-off. Returned to land at reduced power. > John > ------ > > Been there, done that. (the blown-off intake hose) > > Also: > > I have burned out 2 turbos. The first caused precautionary/urgent landin= g > at an airport pending shutting off fuel flow to the turbo. The second, I > flipped a turbo oil shut off switch and flew 1000NM to get home. > > > > Had a fuel pump die in flight, switched to the other and kept flying.(sof= t > failure) > > I had a bad injector enable switch causing rough running during some phas= e > one flying (after major change)... landed normally > > > Forgot to re-connect fuel return line in engine bay after doing some work= . > dumped a couple gallons of fuel onto the running engine until I smelled g= as > and shut down the engine.. (never left the parking space - but it could h= ave > been really bad. > > > Cracked alternator mount bracket found on pre-flight during phase one > testing. Would have lost cooling and alternator if it happened now. > > > PSRU sun gear pin broke from a backfire during run-up. Was able to taxi > back but would not have been able to fly. > > This is good - broke a coolant line in flight and smelled coolant... > landed at nearby airport and taxied up to restaurant with steam spewing o= ut > of the cowl. Me and my buddy calmly walked into the restaurant and had > breakfast. Afterward, we borrowed some tools and fixed the coolant line. > Went back into the restaurant to ask for 2 pitchers of water to put in ou= r > plane. Continued ski trip to Mammoth. The end. > > -- > David Leonard > > Turbo Rotary RV-6 N4VY > http://N4VY.RotaryRoster.net > http://RotaryRoster.net > > On Sun, Apr 12, 2009 at 2:03 PM, Mark Steitle wrote: > > Thanks Bill, > > With the addition of Bill's exciting adventure, and one of my own, we're = up > to 18 incidents in the database. These last two, along with Ed's brake > fire, and an oil coolant rupture, totals four incidents involving fires > during ground operations. Hopefully, everyone carries at least one fire > extinguisher in their airplane. > > Mark S. > > > > On Sun, Apr 12, 2009 at 2:56 PM, Bill Schertz > wrote: > > One other thing to watch out for -- This occurred during ground testing, > but if it had happened in the air it would have been a forced landing. > > > > From my post of Feb. 8 > > Well, I haven't heard of this happening before -- I was ground running my > engine to tune it with the EM-2 and EC-2. Ran for almost an hour, at > various rpm's to change the manifold pressure and tweak the settings. > Cooling working well, I had the top cowling off to allow good exit area > since I was tied down. Coolant pressure about 14 psi as reported on the > EM-2. > > > > Engine was running good, took it up to ~6000 rpm swinging a 76x76 Catto > prop, when suddenly there was steam and fluid on my windshield. Shut it d= own > by killing power to the EC-2. Coolant everywhere. > > > > Got out and looked to diagnose the problem -- NOT my plumbing. A FREEZE > PLUG in the iron housing had blown out. Rapid coolant dump. > > > > Secondary effect -- Since I shut down suddenly from full tilt, either the > proximity of the cowl to the exhaust, or possibly some of the coolant on = the > exhaust started a small fire on my cowl. Put it out with extinguisher, bu= t > corner is charred. > > > > Now in repair mode. > > > > -------------------------- > > Update since this incident: All freeze plugs (7) on the engine have been > replaced by Bruce Turrentine, and he has inspected the engine. I am > currently reinstalling it and getting ready for more tuning exercises. > > > > Bill Schertz > KIS Cruiser #4045 > N343BS > > ----- Original Message ----- > > *From:* Mark Steitle > > *To:* Rotary motors in aircraft > > *Sent:* Sunday, April 12, 2009 1:51 PM > > *Subject:* [FlyRotary] Re: forced landings > > > > Charlie, > > That's a very good point. I'm trying to stay away from assigning a "caus= e" > for whatever happened because I don't have all the facts. I have a field > that says "Explanation of Failure". Hopefully, we can make statements as > you suggest. Sometimes, even the FAA gets it wrong, like the time they > attributed the engine failure to the builder removing the oil injection > pump. Also, I doubt that we could all agree on a "single cause" for each > failure. Maybe it is due to a poor weld, or wrong choice of material, or > improper strain relief, or lack of heat shielding, or a little of each. > What I hope to accomplish is to point out areas where we need to be more > careful on how we design a particular part or system. > > List is at 16 now. Anyone else want to add a "dark and stormy night" sto= ry > to the list? > > Mark > > On Sun, Apr 12, 2009 at 11:46 AM, Charlie England > wrote: > > I think that it's just as important to understand the real cause of the > failure. In the case of the plastic fuel flow sensor, it's highly unlikel= y > that use of the plastic sensor caused the failure; it was the use of plas= tic > in the wrong area without any protection. The homebuilder's knee-jerk > reaction is to say 'no plastic sensors because that one melted', even tho= ugh > there are tens of thousands of the same sensor in use in boating, a much > more severe environment. > > Kind of like the canard builder who tried to put fuel in a wing built wit= h > fuel-soluble foam. Obviously, it failed, but only because of the wrong > application of products, not the products themselves. > > Charlie > > > ------------------------------ > > *From:* al wick > > > *To:* Rotary motors in aircraft > > *Sent:* Sunday, April 12, 2009 10:13:00 AM > *Subject:* [FlyRotary] Re: forced landings > > > > Absolutely excellent Mark. I'd encourage you to get the year the incident > occured too. That will be your proof of reduced risk from things like thi= s > newsgroup. > > Avoid the black and white approach: forced landing or not forced. Because > all things are shades of grey. Instead rate the severity. So it's a 10 if > the guy had to glide, it's a 1 if he did precautionary landing. If you al= so > explain what happened, then a reader can easily tell you were objective i= n > your rating. > > The final piece is about how many flight hours, first flights there were. > Each year there are more engines flying, so way more likely you will hear= of > incident. A wild assed guess is ok, if you just base the guess on some > facts. For example, you could check faa database and find 100 planes > registered with rotary engine in 2005. You can guess that equals 70 hours > each. Even though it's a wild assed guess, it will still be excellent > predictor of change over time. Each year you have the same "error". So yo= ur > numbers WILL reflect improvement. > > More important than anything. If you can force your self to say: "That sa= me > failure will happen to me". Particularly if you can look at "contributing > factors". Then you can dramatically reduce personal risk. Good example: W= e > had that guy that installed plastic fuel flow sensor in fuel line. It > melted, he died. Tracy just reported hot exhaust caused fuel to boil out = of > carb. These have the same root cause. You don't want to say:" I have efi, > can't happen to me". You want to say:" I expect heat will cause a failure= . > I'll put a thin ss shield here, with a bit of fibrefax glued to back. So = if > muffler fails, it won't affect....." > > Every forced landing had 10 little incidents in the past that preceded it= . > Your risk isn't some new cause. It's 1 of those 10 incidents that you > rationalized away, instead of saying:" that will happen to me too." > > Good stuff. > > > -al wick > Cozy IV with 3.0 liter Subaru > 230+ hrs tt from Portland, Oregon > > ---------- Original Message ---------- > From: Mark Steitle > To: "Rotary motors in aircraft" > Subject: [FlyRotary] Re: Gary Casey was [FlyRotary] Re: Rotary Engines > Date: Sun, 12 Apr 2009 06:45:24 -0500 > > Mike, > > Has anyone ever tried to document the rotary incidents resulting in a > forced landing? > > Here's what I recall from memory, so it likely is missing a few; > > 3 forced landings due to ruptured oil coolers > 1 forced landing due to apex seal coming out of its slot (rotor out o= f > spec) > 1 forced landing due to improper assembly of engine (seal wedged > between rotor & side housing) > 1 forced landing on highway due to catastrophic overheating of engine > 2 forced landings (one fatal) due to probable fuel system design flaw > 1 forced landing on highway due to ingestion of FOD. > > There were a few others, such as turbo failures which allowed for continu= ed > operation at reduced power, so we may or may not wish to include those > here. > > While a number of these incidents date back quite a few years, and we hav= e > made excellent progress, it says to me that we still have room for > improvement in the peripheral department. The good news is that out of a= ll > of the incidents listed above, none of them were caused by a true engine > failure. That's where the rotary has really earned my respect as a viabl= e > a/c engine. > > Pay attention to the details! > > Mark S. > > On Sat, Apr 11, 2009 at 9:22 PM, Mike Wills wrote: > > This has been an interesting thread. In the end, it doesnt really matte= r > how many "major" parts you have - even a minor failure can bring you down= . > While I believe the basic rotary engine itself is more fault tolerant tha= n a > recip, the peripherals used in the typical rotary install are a lot more > complex than a typical recip install. Since we rotary fliers dont have th= e > benefit of 70 years worth of experience flying behind the typical LyCon f= arm > implement I think overall our odds are considerably worse. Comes down to = how > well an individual engineer's his installation and there is a tremendous > amount of variation here. > > > > The dependence on electronics in the typical rotary install is a good > example. I may be a little sensitive to this issue since I've been trying= to > find an intermittent glitch (2 times in 22 hours of engine testing). > > > > Mike Wills > > RV-4 N144MW > > ----- Original Message ----- > > *From:* Ed Anderson > > *To:* Rotary motors in aircraft > > *Sent:* Saturday, April 11, 2009 7:31 AM > > *Subject:* [FlyRotary] Gary Casey was [FlyRotary] Re: Rotary Engines > > > > Good analysis and logic, Gary. > > > > You=92d make a good addition to the =93rotary community=94. I have notic= ed over > the 10 years I have been flying my rotary powered RV-6A that the problems > have decreased considerably, the success rate and completion rate has gon= e > up and first flights are now occurring without significant problems =96 e= ven > cooling is OK {:>). I believe most of this improvement can be attributed= to > folks sharing their knowledge, problems and solutions with others - such = as > on this list. > > > > I know that fewer parts count is often touted as one of the rotary benefi= t > =96 and while it is true that the part count is lower, the most significa= nt > thing (in my opinion) is not only does the lower part count help reliabil= ity > (if it is not there =96 it can not break), but if you look a the design o= f the > eccentric shaft (for example) you notice the absence of the jogs in a > typical crankshaft and their stress points. The thing is over 3=94 in > diameter at some points and does not have the same inertia loads born by = a > piston crankshaft. The parts that are there are of very robust design. > Finally, the rotary is (I believe) more tolerant of damage and tends to f= ail > =93gradually and gracefully=94, it can take a licking and keep on ticking= as the > old saying goes. Only extended time and numbers will provide the true MT= BF > for the rotary, but I believe it looks very promising. > > > > Failure of rotary engines are extremely rare, but unfortunately, as with > many alternative engine installations, auxiliary subsystems such as fuel = and > ignition frequently being one-off designs have been the cause of most > failures =96 with probably fuel the prime culprit. The good news is that= for > some platforms (such as the RVs) we have pretty much established what wil= l > make an installation successful. The Canard crowd is fast approaching th= at > status with their somewhat more challenging cooling requirements being ov= er > come. > > > > Having lost a rotor during flight due to putting in high compression > rotors with worn apex seal slots worn beyond specs (found this out later = =96 > my fault for not being aware of this spec limit and checking it) which le= d > to apex seal failure and consequence lost of most of the power from one > rotor, I was still able to maintain 6500 MSL at WOT and fuel mixture knob= to > full rich =96 flowing 14.5 GPH =96 a lot of it undoubtedly being blown t= hrough > the disabled rotor. Flew it back 60 miles to a suitable runway and made = a > non-eventful landing. There was a small increase in vibration due to th= e > power strokes no longer being balanced, but nothing bad and you could sti= ll > read the needles on the gauges. Other folks have had FOD damage to a rot= or > and also make it to a safe landing. Two folks lost cooling (one loss of > coolant fluid , one lost of water pump) and while they did cook the engin= es, > both made it back to a safe landing. So all things considered, I think t= he > rotary continues to show that if the installation is designed properly, i= t > makes a very viable and reliable aircraft power plant. > > > > Failure of rotary engines in aircraft are extremely rare, but > unfortunately, as with many alternative engine installations, auxiliary > subsystems such as fuel and ignition frequently being one-off designs - h= ave > been the cause of most failures. The good news is that for some platform= s > (such as the RVs) we have pretty much established what will make an > installation successful. The Canard crowd is fast approaching that statu= s > with their somewhat more challenging cooling requirements being over come= . > > > > My rotary installation cost me $6500 back in 1996, the primary cost being= a > rebuilt engine $2000 and the PSRU $2900. I have since purchased a 1991 > turbo block engine from Japan for $900 and rebuilt it myself for another > $2200. My radiators (GM evaporator cores) cost $5.00 from the junk yard = and > another $50.00 each for having the bungs welded on. So depending on how > much you buy and how much you build the price can vary considerably. Tod= ay, > I would say it would take a minimum of around $8000 and more nominally > around $10000 for a complete rotary installation in an RV =96 some folks = could > do it for less, some for more. > > > > But, regardless of the technical merit (or not) in someone=92s mind, the > crucial thing (in my opinion) is you need to address two personal factors= : > > > > 1. What is your risk tolerance? It doesn=92t really matter how sexy som= e > =93exotic=94 engine installation may seem =96 if you are not comfortable = flying > behind (or in front) of it, then it certainly does not makes sense to go > that route. After all, this is supposed to have an element of fun and > enjoyment to it. > > > > 2. What is your knowledge, experience and background (and you don=92t ha= ve > to be an engineer) and do you feel comfortable with the level of involvem= ent > needed. > > > > So hope you continue to contribute to expanding our knowledge and > understanding of the rotary in its application to power plant for aircraf= t. > > > > > > Best Regards > > > > Ed > > > > > > Ed Anderson > > Rv-6A N494BW Rotary Powered > > Matthews, NC > > eanderson@carolina.rr.com > > http://www.andersonee.com > > http://www.dmack.net/mazda/index.html > > http://www.flyrotary.com/ > > http://members.cox.net/rogersda/rotary/configs.htm#N494BW > > http://www.rotaryaviation.com/Rotorhead%20Truth.htm > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Gary Casey > *Sent:* Saturday, April 11, 2009 8:36 AM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Rotary Engines > > > > Just to add a few more comments and answers to the several excellent > comments posted: > > > > How many parts does it take to make a rotary rotate? Well, "parts aren't > parts" in this case. Mark was right in that there are maybe 4 "major" > components, but you have to define major. A piston engine certainly has = far > more major parts. Is a valve a "major" part? I think so. Is a rotor > corner button a major part? Not sure, but probably not. Is each planet > gear in the PSRU a major part? I say yes, and the PSRU is an integral pa= rt > of the rotary engine. As someone correctly pointed out, it's not how man= y > parts, but the reliability of the total system that counts. Just looking= at > the history of the rotary (which, from the implication of another post) i= t's > not that good, but I don't think it has anything to do with reliability o= f > the concept. It's more to do with the experimental nature of the builds = and > installations. My original point, perhaps not well expressed is that to = say > there are just 4 parts is an oversimplification. But let's face it, to p= ut > in an engine that has had many thousands of identical predecessors is les= s > "experimental" than one that hasn't.. > > > > Are we ES drivers more conservative? Probably so, since the ES is probab= ly > one of the experimentals most similar to production aircraft, and not jus= t > because the Columbia (can't force myself to say Cezzna :-) was a derivati= ve. > Therefore, it tends to attract conservative builders and owners. Not > surprising then that almost all ES's have traditional powerplants, with t= he > most excellent exception of Mark. While there may be more, I know of onl= y > two off-airport landings caused by engine failures in the ES in almost 20 > years of experience. One was caused by fuel starvation right after takeo= ff > (fatal) and one was caused by a PSRU failure in an auto engine conversion= . > So our old-fashioned conservative nature has served us pretty well. > > > > Yes, I was assuming that the rotary had electronic fuel injection and > ignition, but that by itself doesn't change the inherent fuel efficiency = of > the engine. Direct injection does have a potential to improve BSFC becau= se > the fuel charge can be stratified. It will probably decrease available > power, though. I think the best rotary will be 5% less efficient than th= e > "best" piston engine(same refinements added to each). But I stated that = as > a simple disadvantage - as Mark pointed out, it isn't that simple. The > rotary already comes configured to run on auto gas. The piston engine ca= n > also be so configured, but the compression ratio reduction would reduce i= ts > BSFC and maybe durability advantage. The total operating cost is certain= ly > significantly less if auto gas can always be used to refuel. I assumed i= n > my assessment that it will only be available 50% of the time. The real > disadvantage, which I failed to state, is that the extra fuel required fo= r a > given mission might be 5 or 10% higher and that negated the weight > advantage, if only for long-range flights. > > > > Is the engine less expensive? I did a thorough analysis of a direct-driv= e > recip auto engine installation and my conclusion was that if the auto eng= ine > were equivalent in reliability to the aircraft engine it would likely cos= t > just as much. Is the same true of the rotary? I'm not sure, but you hav= e > to consider the total cost, including engineering of all the parts in the > system, not just the core engine. I would love to do a rotary installati= on, > but I don't think I could justify it by cost reduction. > > > > It wasn't mentioned in the posts, but some have claimed the rotary is > "smoother" than a recip. I at first resisted that notion. Sure, any rot= ary > given sufficient counterbalancing, is perfectly balanced. A 4-cylinder > opposed recip is not - there is a significant secondary couple. The > 6-cylinder opposed engine is perfectly balanced, but only for PRIMARY and > SECONDARY forces and couples - higher order forces have never really been > analyzed, although they would be very small. And then consider the force= s > within the engine that have to be resisted by that long, heavy, but flexi= ble > crankshaft. So it isn't the mechanical balance that gives the rotary an > advantage. Let's take a look at the the torsional pulsations, comparing = the > 3-rotor against the 6-cylinder: A 6-cylinder engine has 3 power impulses > per rotation, as does the 3-rotor, so they are the same, right? Wrong. > They both incorporate 4 "stroke" cycles, meaning that there separate and > sequential intake, compression, power and exhaust events so that is the s= ame > for both. The power event, which is the source of the torque impulse, ta= kes > 1/2 of a crank rotation for the recip. In the rotary the power event > requires 1/4 of a ROTOR rotation, but the rotor rotates at 1/3 crank > rotation - the result is that the power impulse lasts 3/4 of a CRANK > rotation, 50% longer than in a recip. Therefore, the torsional excitatio= n > delivered to the propeller, PSRU and to the airframe is significantly les= s > than for a recip. And if you analyze the actual forces imparted, they go > down by the square of the rpm. The torsional vibration amplitude goes do= wn > by a factor of 4 just because the rpm of the rotary turns about twice as > fast. If you've skipped to the bottom of the paragraph, as you probably > should have :-), yes the rotary is "smoother" - a LOT smoother.. (my > apologies to rotary purists, for simplicity I used the word "crankshaft" = for > both engines) > > > > But just because you can burn auto gas should you? The biggest problems > with auto gas in recip aircraft have nothing to do with the engine, but w= ith > the high vapor pressure of the fuel - it is more prone to vapor lock. Th= e > fuel systems of certified aircraft are not particularly well designed wit= h > regard to vapor lock. "Fortunately", rotary engines typically have no > mechanical fuel pump and are forced to rely on electric pumps. Fortunate= ly > because the pumps can be located at the very bottom of the aircraft and > close to the fuel tanks, making vapor lock much less likely. I would > caution any builders to consider vapor lock possibilities very seriously, > much more so if you intend to run auto gas. when I was going to do this = I > planned to put one electric pump in the wing root of each wing, feeding t= he > engine directly(the check valve in the non-running pump prevents > back-feeding). Redundancy was by a "crossfeed" line that could connect t= he > tanks together. > > > > And thanks, Mark for - probably incorrectly - referring to me as a "good > engineer". I'll have to put that in my resume! > > > > Have a good day, > > Gary > > (do you allow us outsiders in your events? I'll park well away :-) > > > > > > > __________ Information from ESET NOD32 Antivirus, version of virus > signature database 3267 (20080714) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com/ > > > > > > > > > > > -- > David Leonard > > Turbo Rotary RV-6 N4VY > http://N4VY.RotaryRoster.net > http://RotaryRoster.net > > > > > > --0016e644cf32a724980467764f12 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Thats a good question.=A0 Probably a big espensive machine somewhere t= hat I can't afford.=A0 I guess thats why mine pop off occasionally.
=A0
--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net


On Mon, Apr 13, 2009 at 2:17 PM, Bill Bradburry = <bbradburr= y@bellsouth.net> wrote:

Dave=92s number 4 below brings up a= question I have been pondering.

=A0

How do you put a bead on the ends o= f aluminum tubing so the hose will not slip off???

=A0

My tubing is inch and a quarter and= probably 0.060 thick.=A0 Suggestions appreciated.

=A0

Thanks,

Bill B

=A0

From: Rota= ry motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of David Leonard
Sent: Monday, April 13, 200= 9 4:48 PM=20


To: R= otary motors in aircraft
Subj= ect: [FlyRotary] Re: forced landings=20

http://N4VY.RotaryRoster.net
= http://RotaryRoster.= net

msteitle@gmail.com> wrote:

= Mark S.

wdleonard@gmail.com> wrote:

jslade@canardaviation.com>= wrote:

= Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net=
http://RotaryRos= ter.net

msteitle@gmail.com> wrote:

wschertz@comcast.net> wrote:

One other thing to watch out for -- This occurred during ground= testing, but if it had happened in the air it would have been a forced lan= ding.

From=A0 my post of Feb. 8

Well, I haven't heard of this happening before -- I was gro= und running my engine to=A0 tune it with the EM-2 and EC-2.=A0 Ran for almo= st an hour, at various rpm's to change the manifold pressure and tweak = the settings. Cooling working well, I had the top cowling off to allow good= exit area since I was tied down. Coolant pressure about 14 psi as reported= on the EM-2.

Engine was running good, took it up to ~6000 rpm swinging a 76x= 76 Catto prop, when suddenly there was steam and fluid on my windshield. Sh= ut it down by killing power to the EC-2. Coolant everywhere.<= /p>

Got out and looked to diagnose the problem -- NOT my plumbing.= =A0 A FREEZE PLUG in the iron housing had blown out. Rapid coolant dump.

Secondary effect -- Since I shut down suddenly from full tilt, = either the proximity of the cowl to the exhaust, or possibly some of the co= olant on the exhaust started a small fire on my cowl. Put it out with extin= guisher, but corner is charred.

Now in repair mode.

--------------------------

Update since this incident:=A0 All freeze plugs (7) on the engi= ne have been replaced by Bruce Turrentine, and he has inspected the engine.= I am currently reinstalling it and getting ready for more tuning exercises= .

Bill Schertz
KIS Cruiser #4045
N= 343BS

----- Original Message -----

From: Mark Steitle

Sent: Sunday, = April 12, 2009 1:51 PM

Subject: [FlyR= otary] Re: forced landings

= Charlie,

That's a very good poin= t.=A0 I'm trying to stay away from assigning a "cause" for wh= atever happened because I don't have all the facts.=A0 I have a field t= hat says "Explanation of Failure".=A0 Hopefully, we can make stat= ements as you suggest.=A0 Sometimes, even the FAA gets it wrong, like the t= ime they attributed the engine failure to the builder removing the oil inje= ction pump.=A0 Also, I doubt that we could all agree on a "single caus= e" for each failure.=A0 Maybe it is due to a poor weld, or wrong choic= e of material, or improper strain relief, or lack of heat shielding, or a l= ittle of each.=A0 What I hope to accomplish is to point out areas where we = need to be more careful on how we design a particular part or system.=A0
List is at 16 now.=A0 Anyone else want to add a "dark and stormy n= ight" story to the list?=A0

Mark =A0=A0

ceengland@bellsouth.net> w= rote:

From: al w= ick <alwick@juno.co= m>


To: Rotar= y motors in aircraft <flyrotary@lancaironline.net>

Sent: Sund= ay, April 12, 2009 10:13:00 AM
Subject: [FlyRotary] Re: fo= rced landings

=
-al wick
Cozy IV with 3.0 liter Suba= ru
230+ hrs tt from Portland, Oregon

---------- Original Message = ----------
From: Mark Steitle <msteitle@gmail.com>
To: "Rotary motors in aircraft"= <flyro= tary@lancaironline.net>
Subject: [FlyRotary] Re: Gary Casey was [FlyRotary] Re: Rotary Engines
D= ate: Sun, 12 Apr 2009 06:45:24 -0500

Mike,

Has anyone ever t= ried to document the rotary incidents resulting in a forced landing?

Here's what I recall from memory, so it likely is missing a few;=A0
=A0=A0=A0 3 forced landings due to ruptured oil coolers
=A0=A0= =A0 1 forced landing due to apex seal coming out of its slot (rotor out of = spec)
=A0=A0=A0 1 forced landing due to improper assembly of engine (sea= l wedged between rotor & side housing)
=A0=A0=A0 1 forced landing on highway due to catastrophic overheating of en= gine
=A0=A0=A0 2 forced landings (one fatal) due to probable fuel system= design flaw=A0
=A0=A0=A0 1 forced landing on highway due to ingestion = of FOD.=A0

There were a few others, such as turbo failures which allowed for continued= operation at reduced power, so we may or may not wish to include those her= e.=A0

While a number of these incidents date back quite a few years= , and we have made excellent progress, it says to me that we still have roo= m for improvement in the peripheral department.=A0 The good news is that ou= t of all of the incidents listed above, none of them were caused by a true = engine failure.=A0 That's where the rotary has really earned my respect= as a viable a/c engine.

Pay attention to the details!

Mark S.

rv-4mike@cox.net> wrote:<= /p>

This has been an interesting thread. In the end, it doesnt real= ly matter how many "major" parts you have - even a minor failure = can bring you down. While I believe the basic rotary engine itself is more = fault tolerant than a recip, the peripherals used in the typical rotary ins= tall are a lot more complex than a typical recip install. Since we rotary f= liers dont have the benefit of 70 years worth of experience flying behind t= he typical LyCon farm implement I think overall our odds are considerably w= orse. Comes down to how well an individual engineer's his installation = and there is a tremendous amount of variation here.

The dependence on electronics in the typical rotary install=A0 = is a good example. I may be a little=A0sensitive to this issue since I'= ve been trying to find an intermittent glitch (2 times in 22 hours of engin= e testing).

Mike Wills

RV-4 N144MW=A0=A0

=

----- Original Message -----

From: Ed Anderson

Sent: Saturday= , April 11, 2009 7:31 AM

Subject: [FlyR= otary] Gary Casey was [FlyRotary] Re: Rotary Engines

Good analysis and logic, Gary.

You=92d make a good addition to the= =93rotary community=94.=A0 I have noticed over the 10 years I have been fl= ying my rotary powered RV-6A that the problems have decreased considerably,= the success rate and completion rate has gone up and first flights are now= occurring without significant problems =96 even cooling is OK {:>).=A0 = I believe most of this improvement can be attributed to folks sharing their= knowledge, problems and solutions with others - such as on this list.=A0 <= /span>

I know that fewer parts count is of= ten touted as one of the rotary benefit =96 and while it is true that the p= art count is lower, the most significant thing (in my opinion) is not only = does the lower part count help reliability (if it is not there =96 it can n= ot break), but if you look a the design of the eccentric shaft (for example= ) you notice the absence of the jogs in a typical crankshaft and their stre= ss points.=A0 The thing is over 3=94 in diameter at some points and does no= t have the same inertia loads born by a piston crankshaft.=A0 The parts tha= t are there are of very robust design.=A0 Finally, the rotary is (I believe= ) more tolerant of damage and tends to fail =93gradually and gracefully=94,= it can take a licking and keep on ticking as the old saying goes.=A0 Only = extended time and numbers will provide the true MTBF for the rotary, but I = believe it looks very promising.

Failure of rotary engines are extre= mely rare, but unfortunately, as with many alternative engine installations= , auxiliary subsystems such as fuel and ignition frequently being one-off d= esigns have been the cause of most failures =96 with probably fuel the prim= e culprit.=A0 The good news is that for some platforms (such as the RVs) we= have pretty much established what will make an installation successful.=A0= The Canard crowd is fast approaching that status with their somewhat more = challenging cooling requirements being over come.

=A0 Having lost a rotor during flig= ht due to putting in high compression rotors with worn apex seal slots worn= beyond specs (found this out later =96 my fault for not being aware of thi= s spec limit and checking it) which led to apex seal failure and consequenc= e lost of most of the power from one rotor, I was still able to maintain 65= 00 MSL at WOT and fuel mixture knob to full rich =96 flowing 14.5 GPH =96 a= lot of it undoubtedly =A0being blown through the disabled rotor.=A0 Flew i= t back 60 miles to a suitable runway and made a non-eventful landing.=A0=A0= There was a small increase in vibration due to the power strokes no longer= being balanced, but nothing bad and you could still read the needles on th= e gauges.=A0 Other folks have had FOD damage to a rotor and also make it to= a safe landing.=A0 Two folks lost cooling (one loss of coolant fluid , one= lost of water pump) and while they did cook the engines, both made it back= to a safe landing.=A0 So all things considered, I think the rotary continu= es to show that if the installation is designed properly, it makes a very v= iable and reliable aircraft power plant.

Failure of rotary engines in aircra= ft are extremely rare, but unfortunately, as with many alternative engine i= nstallations, auxiliary subsystems such as fuel and ignition frequently bei= ng one-off designs - have been the cause of most failures.=A0 The good news= is that for some platforms (such as the RVs) we have pretty much establish= ed what will make an installation successful.=A0 The Canard crowd is fast a= pproaching that status with their somewhat more challenging cooling require= ments being over come.

My rotary installation cost me $650= 0 back in 1996, the primary cost being a rebuilt engine $2000 and the PSRU = $2900.=A0 I have since purchased a 1991 turbo block engine from Japan for $= 900 and rebuilt it myself for another $2200. =A0My radiators (GM evaporator= cores) cost $5.00 from the junk yard and another $50.00 each for having th= e bungs welded on.=A0 So depending on how much you buy and how much you bui= ld the price can vary considerably.=A0 Today, I would say it would take a m= inimum of around $8000 and more nominally around $10000 for a complete rota= ry installation in an RV =96 some folks could do it for less, some for more= .

But, regardless of the technical me= rit (or not) in someone=92s mind, the crucial thing (in my opinion) is you = need to address two personal factors:

1.=A0 What is your risk tolerance?= =A0 It doesn=92t really matter how sexy some =93exotic=94 engine installati= on may seem =96 if you are not comfortable flying behind (or in front) of i= t, then it certainly does not =A0makes sense to go that route.=A0 After all= , this is supposed to have an element of fun and enjoyment to it.

2.=A0 What is your knowledge, exper= ience and background (and you don=92t have to be an engineer) and do you fe= el comfortable with the level of involvement needed.

So hope you continue to contribute = to expanding our knowledge and understanding of the rotary in its applicati= on to power plant for aircraft.

Best Regards

Ed

Ed Anderson

Rv-6A N494BW Rotary P= owered

Matthews, NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/maz= da/index.html

http://www.flyrotary.com/

http://memb= ers.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.rotaryaviation.co= m/Rotorhead%20Truth.htm

From: Rota= ry motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Gary Casey
Sent: Saturday, April 11, 2= 009 8:36 AM
To: Rotary m= otors in aircraft
Subject: [FlyRotary] Re: Rotary Engines

=


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--
David Leonard

Turbo Rotary RV-6 N= 4VY
http://N= 4VY.RotaryRoster.net
http://RotaryRoster.= net




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