X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-ew0-f167.google.com ([209.85.219.167] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3579739 for flyrotary@lancaironline.net; Mon, 13 Apr 2009 17:12:06 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.219.167; envelope-from=msteitle@gmail.com Received: by ewy11 with SMTP id 11so3340904ewy.19 for ; Mon, 13 Apr 2009 14:11:30 -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=efrJiAhAPEqTGL9gjr/xHOIHKR7Qrr/dcfjrXpJBci8=; b=JlxTYux8NtkW88UqyqCk/e+jnV7b+O8VmvCozSj4ilqUL0x5TxkMFE0l3hTQRttKQg zRxJApIFVC8eWeMMMAyXIKqeHRm7zr6FckMv2l7ujpIDRJdLxnDbOGmG8QIVqC+vV9fa nDlxPYr9pNg5qW/Wx+NcXiGNWa1rAsMpF0KTc= 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=efIbX4GsKXDcU4QWpw3UJbUNOq0ZpFJsE3rnTBAQ+rKhyiT9Vc0X6PE3b3E85EN3md mnXqnOSm66DpEDgaemtkRHLkeaq2czHOW1LuaJpTRsuNlgzARDUH+/cvohoEHYT5GVMr r0yTBps3eyISjlBQsJNEl5EPRcnwm1RJ5VlTM= MIME-Version: 1.0 Received: by 10.210.136.10 with SMTP id j10mr4788829ebd.11.1239657090451; Mon, 13 Apr 2009 14:11:30 -0700 (PDT) In-Reply-To: References: Date: Mon, 13 Apr 2009 16:11:30 -0500 Message-ID: <5cf132c0904131411w4ab2f741rae5aa3c5cf2fac3@mail.gmail.com> Subject: Re: [FlyRotary] Re: forced landings From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015174bdeaa850b8f0467762803 --0015174bdeaa850b8f0467762803 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Dave, You're definitely in tune with the intent of the database. And I'm just trying to keep it managable. I will go ahead and include items discovered during preflight or maintenance which in all probability would have resulte= d in an in-flight failure. Those will get a pucker factor (PF) rating of 1. An example would be Ed's oil pump failure due to a missing woodruff key. Incidents that happened in flight that resulted in loss of power, but continued flight was possible, will receive a PF rating of 2. Such as a turbo hose blowing off. Incidents that happened in the air that resulted in a precautionary landing will be rated a PF 3. Incidents which happened in the air which necessitated a forced landing (on or off field) will get a PR of 4. And finally, incidents which resulted in a crash and/or fatality will be rated PF 5. So, when reporting failures, please provide enough information for me to determine the proper PF rating. Thanks, Mark On Mon, Apr 13, 2009 at 3:47 PM, David Leonard wrote: > 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 wr= ote: >> >>> Mark, And did you get these? Added by me and John Slade under the wron= g >>> 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 >>> landing 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 ho= me. >>> >>> Had a fuel pump die in flight, switched to the other and kept >>> flying.(soft failure) >>> I had a bad injector enable switch causing rough running during some >>> phase 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 gas and shut down the engine.. (never left the parking space - = but >>> it could have 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 tax= i >>> 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= out >>> of the cowl. Me and my buddy calmly walked into the restaurant and had >>> breakfast. Afterward, we borrowed some tools and fixed the coolant lin= e. >>> Went back into the restaurant to ask for 2 pitchers of water to put in = our >>> 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 wro= te: >>> >>>> 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 b= rake >>>> fire, and an oil coolant rupture, totals four incidents involving fire= s >>>> during ground operations. Hopefully, everyone carries at least one fi= re >>>> extinguisher in their airplane. >>>> >>>> Mark S. >>>> >>>> On Sun, Apr 12, 2009 at 2:56 PM, Bill Schertz wr= ote: >>>> >>>>> 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 force= d >>>>> landing. >>>>> >>>>> From my post of Feb. 8 >>>>> Well, I haven't heard of this happening before -- I was ground runnin= g >>>>> 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 ar= ea >>>>> since I was tied down. Coolant pressure about 14 psi as reported on t= he >>>>> EM-2. >>>>> >>>>> Engine was running good, took it up to ~6000 rpm swinging a 76x76 Cat= to >>>>> prop, when suddenly there was steam and fluid on my windshield. Shut = it down >>>>> 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 coo= lant on >>>>> the exhaust started a small fire on my cowl. Put it out with extingui= sher, >>>>> but 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 >>>>> "cause" for whatever happened because I don't have all the facts. I = have a >>>>> field that says "Explanation of Failure". Hopefully, we can make sta= tements >>>>> as you suggest. Sometimes, even the FAA gets it wrong, like the time= they >>>>> attributed the engine failure to the builder removing the oil injecti= on >>>>> 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 eac= h. >>>>> What I hope to accomplish is to point out areas where we need to be m= ore >>>>> 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" >>>>> story to the list? >>>>> >>>>> Mark >>>>> >>>>> On Sun, Apr 12, 2009 at 11:46 AM, Charlie England < >>>>> ceengland@bellsouth.net> 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 highl= y >>>>>> unlikely that use of the plastic sensor caused the failure; it was t= he use >>>>>> of plastic in the wrong area without any protection. The homebuilder= 's >>>>>> knee-jerk reaction is to say 'no plastic sensors because that one me= lted', >>>>>> even though 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 buil= t >>>>>> with fuel-soluble foam. Obviously, it failed, but only because of th= e 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 t= hings >>>>>> like this 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 >>>>>> also explain what happened, then a reader can easily tell you were o= bjective >>>>>> in 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 yo= u will >>>>>> hear of incident. A wild assed guess is ok, if you just base the gue= ss on >>>>>> some facts. For example, you could check faa database and find 100 p= lanes >>>>>> 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 excellen= t >>>>>> predictor of change over time. Each year you have the same "error". = So your >>>>>> numbers WILL reflect improvement. >>>>>> >>>>>> More important than anything. If you can force your self to say: "Th= at >>>>>> same failure will happen to me". Particularly if you can look at >>>>>> "contributing factors". Then you can dramatically reduce personal ri= sk. Good >>>>>> example: We had that guy that installed plastic fuel flow sensor in = fuel >>>>>> line. It melted, he died. Tracy just reported hot exhaust caused fue= l 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 glue= d to >>>>>> back. So if muffler fails, it won't affect....." >>>>>> >>>>>> Every forced landing had 10 little incidents in the past that preced= ed >>>>>> it. Your risk isn't some new cause. It's 1 of those 10 incidents tha= t 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 Engin= es >>>>>> 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 of 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 >>>>>> continued operation at reduced power, so we may or may not wish to i= nclude >>>>>> those here. >>>>>> >>>>>> While a number of these incidents date back quite a few years, and w= e >>>>>> have 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 all >>>>>> of the incidents listed above, none of them were caused by a true en= gine >>>>>> failure. That's where the rotary has really earned my respect as a = viable >>>>>> a/c engine. >>>>>> >>>>>> Pay attention to the details! >>>>>> >>>>>> Mark S. >>>>>> >>>>>> >>>>>> On Sat, Apr 11, 2009 at 9:22 PM, Mike Wills wrot= e: >>>>>> >>>>>>> This has been an interesting thread. In the end, it doesnt really >>>>>>> matter how many "major" parts you have - even a minor failure can b= ring you >>>>>>> down. While I believe the basic rotary engine itself is more fault = tolerant >>>>>>> than a recip, the peripherals used in the typical rotary install ar= e a lot >>>>>>> more complex than a typical recip install. Since we rotary fliers d= ont have >>>>>>> the benefit of 70 years worth of experience flying behind the typic= al LyCon >>>>>>> farm implement I think overall our odds are considerably worse. Com= es 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 engin= e >>>>>>> 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 Engine= s >>>>>>> >>>>>>> Good analysis and logic, Gary. >>>>>>> >>>>>>> >>>>>>> >>>>>>> You=92d make a good addition to the =93rotary community=94. I have= noticed >>>>>>> over the 10 years I have been flying my rotary powered RV-6A that t= he >>>>>>> problems have decreased considerably, the success rate and completi= on rate >>>>>>> has gone up and first flights are now occurring without significant= problems >>>>>>> =96 even cooling is OK {:>). I believe most of this improvement ca= n 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 >>>>>>> benefit =96 and while it is true that the part count is lower, the = most >>>>>>> significant thing (in my opinion) is not only does the lower part c= ount help >>>>>>> reliability (if it is not there =96 it can not break), but if you l= ook a the >>>>>>> design of 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 d= esign. >>>>>>> Finally, the rotary is (I believe) more tolerant of damage and tend= s to fail >>>>>>> =93gradually and gracefully=94, it can take a licking and keep on t= icking as the >>>>>>> old saying goes. Only extended time and numbers will provide the t= rue MTBF >>>>>>> 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 su= ch as >>>>>>> fuel and ignition frequently being one-off designs have been the ca= use of >>>>>>> most failures =96 with probably fuel the prime culprit. The good n= ews is that >>>>>>> for some platforms (such as the RVs) we have pretty much establishe= d what >>>>>>> will make an installation successful. The Canard crowd is fast app= roaching >>>>>>> that status with their somewhat more challenging cooling requiremen= ts being >>>>>>> over come. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Having lost a rotor during flight due to putting in high >>>>>>> compression rotors with worn apex seal slots worn beyond specs (fou= nd this >>>>>>> out later =96 my fault for not being aware of this spec limit and c= hecking it) >>>>>>> which led 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 fu= el >>>>>>> mixture knob to full rich =96 flowing 14.5 GPH =96 a lot of it undo= ubtedly >>>>>>> being blown through the disabled rotor. Flew it back 60 miles to = a >>>>>>> suitable runway and made a non-eventful landing. There was a smal= l >>>>>>> increase in vibration due to the power strokes no longer being bala= nced, but >>>>>>> nothing bad and you could still read the needles on the gauges. Ot= her folks >>>>>>> have had FOD damage to a rotor and also make it to a safe landing. = Two >>>>>>> folks lost cooling (one loss of coolant fluid , one lost of water p= ump) and >>>>>>> while they did cook the engines, both made it back to a safe landin= g. So >>>>>>> all things considered, I think the rotary continues to show that if= the >>>>>>> installation is designed properly, it makes a very viable and relia= ble >>>>>>> aircraft power plant. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Failure of rotary engines in aircraft are extremely rare, but >>>>>>> unfortunately, as with many alternative engine installations, auxil= iary >>>>>>> subsystems such as fuel and ignition frequently being one-off desig= ns - have >>>>>>> been the cause of most failures. The good news is that for some pl= atforms >>>>>>> (such as the RVs) we have pretty much established what will make an >>>>>>> installation successful. The Canard crowd is fast approaching that= status >>>>>>> with their somewhat more challenging cooling requirements being ove= r 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 purc= hased a >>>>>>> 1991 turbo block engine from Japan for $900 and rebuilt it myself f= or >>>>>>> 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 de= pending >>>>>>> on how much you buy and how much you build the price can vary consi= derably. >>>>>>> Today, 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 person= al >>>>>>> factors: >>>>>>> >>>>>>> >>>>>>> >>>>>>> 1. What is your risk tolerance? It doesn=92t really matter how se= xy >>>>>>> some =93exotic=94 engine installation may seem =96 if you are not c= omfortable >>>>>>> flying behind (or in front) of it, then it certainly does not make= s sense >>>>>>> to go that route. After all, this is supposed to have an element o= f fun and >>>>>>> enjoyment to it. >>>>>>> >>>>>>> >>>>>>> >>>>>>> 2. What is your knowledge, experience and background (and you don= =92t >>>>>>> have to be an engineer) and do you feel comfortable with the level = of >>>>>>> involvement needed. >>>>>>> >>>>>>> >>>>>>> >>>>>>> So hope you continue to contribute to expanding our knowledge and >>>>>>> understanding of the rotary in its application to power plant for a= ircraft. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> 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] *On 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 excellen= t >>>>>>> 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 a= n >>>>>>> integral part of the rotary engine. As someone correctly pointed o= ut, it's >>>>>>> not how many parts, but the reliability of the total system that co= unts. >>>>>>> Just looking at the history of the rotary (which, from the implica= tion of >>>>>>> another post) it's not that good, but I don't think it has anything= to do >>>>>>> with reliability of the concept. It's more to do with the experime= ntal >>>>>>> nature of the builds and installations. My original point, perhaps= not well >>>>>>> expressed is that to say there are just 4 parts is an oversimplific= ation. >>>>>>> But let's face it, to put in an engine that has had many thousands= of >>>>>>> identical predecessors is less "experimental" than one that hasn't.= . >>>>>>> >>>>>>> >>>>>>> >>>>>>> Are we ES drivers more conservative? Probably so, since the ES is >>>>>>> probably one of the experimentals most similar to production aircra= ft, and >>>>>>> not just because the Columbia (can't force myself to say Cezzna :-)= was a >>>>>>> derivative. Therefore, it tends to attract conservative builders a= nd >>>>>>> owners. Not surprising then that almost all ES's have traditional >>>>>>> powerplants, with the most excellent exception of Mark. While ther= e may be >>>>>>> more, I know of only two off-airport landings caused by engine fail= ures in >>>>>>> the ES in almost 20 years of experience. One was caused by fuel st= arvation >>>>>>> right after takeoff (fatal) and one was caused by a PSRU failure in= an auto >>>>>>> engine conversion. So our old-fashioned conservative nature has se= rved us >>>>>>> pretty well. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Yes, I was assuming that the rotary had electronic fuel injection a= nd >>>>>>> ignition, but that by itself doesn't change the inherent fuel effic= iency of >>>>>>> the engine. Direct injection does have a potential to improve BSFC= because >>>>>>> the fuel charge can be stratified. It will probably decrease avail= able >>>>>>> power, though. I think the best rotary will be 5% less efficient t= han the >>>>>>> "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 eng= ine can >>>>>>> also be so configured, but the compression ratio reduction would re= duce its >>>>>>> BSFC and maybe durability advantage. The total operating cost is c= ertainly >>>>>>> significantly less if auto gas can always be used to refuel. I ass= umed in >>>>>>> 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 requi= red for 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-drive recip auto engine installation and my conclusion was t= hat if >>>>>>> the auto engine were equivalent in reliability to the aircraft engi= ne it >>>>>>> would likely cost just as much. Is the same true of the rotary? I= 'm not >>>>>>> sure, but you have to consider the total cost, including engineerin= g of all >>>>>>> the parts in the system, not just the core engine. I would love to= do a >>>>>>> rotary installation, but I don't think I could justify it by cost r= eduction. >>>>>>> >>>>>>> >>>>>>> >>>>>>> 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, a= ny rotary >>>>>>> given sufficient counterbalancing, is perfectly balanced. A 4-cyli= nder >>>>>>> opposed recip is not - there is a significant secondary couple. Th= e >>>>>>> 6-cylinder opposed engine is perfectly balanced, but only for PRIMA= RY and >>>>>>> SECONDARY forces and couples - higher order forces have never reall= y been >>>>>>> analyzed, although they would be very small. And then consider the= forces >>>>>>> within the engine that have to be resisted by that long, heavy, but= flexible >>>>>>> crankshaft. So it isn't the mechanical balance that gives the rota= ry an >>>>>>> advantage. Let's take a look at the the torsional pulsations, comp= aring the >>>>>>> 3-rotor against the 6-cylinder: A 6-cylinder engine has 3 power im= pulses >>>>>>> per rotation, as does the 3-rotor, so they are the same, right? Wr= ong. >>>>>>> They both incorporate 4 "stroke" cycles, meaning that there separa= te and >>>>>>> sequential intake, compression, power and exhaust events so that is= the same >>>>>>> for both. The power event, which is the source of the torque impul= se, takes >>>>>>> 1/2 of a crank rotation for the recip. In the rotary the power eve= nt >>>>>>> requires 1/4 of a ROTOR rotation, but the rotor rotates at 1/3 cran= k >>>>>>> rotation - the result is that the power impulse lasts 3/4 of a CRAN= K >>>>>>> rotation, 50% longer than in a recip. Therefore, the torsional exc= itation >>>>>>> delivered to the propeller, PSRU and to the airframe is significant= ly less >>>>>>> than for a recip. And if you analyze the actual forces imparted, t= hey go >>>>>>> down by the square of the rpm. The torsional vibration amplitude g= oes down >>>>>>> by a factor of 4 just because the rpm of the rotary turns about twi= ce as >>>>>>> fast. If you've skipped to the bottom of the paragraph, as you pro= bably >>>>>>> should have :-), yes the rotary is "smoother" - a LOT smoother.. (m= y >>>>>>> apologies to rotary purists, for simplicity I used the word "cranks= haft" 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 th= e engine, >>>>>>> but with the high vapor pressure of the fuel - it is more prone to = vapor >>>>>>> lock. The fuel systems of certified aircraft are not particularly = well >>>>>>> designed with regard to vapor lock. "Fortunately", rotary engines = typically >>>>>>> have no mechanical fuel pump and are forced to rely on electric pum= ps. >>>>>>> Fortunately because the pumps can be located at the very bottom of= the >>>>>>> aircraft and close to the fuel tanks, making vapor lock much less l= ikely. I >>>>>>> would caution any builders to consider vapor lock possibilities ver= y >>>>>>> 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 the engine directly(the check valve in the non-running pump= prevents >>>>>>> back-feeding). Redundancy was by a "crossfeed" line that could con= nect the >>>>>>> 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 >>> >> >> > > > --0015174bdeaa850b8f0467762803 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Dave,
=A0
You're definitely in tune with the intent of the database.=A0 And = I'm just trying to keep it managable.=A0 I will go ahead and include=A0= items discovered during preflight or maintenance=A0which in all probability= would have=A0resulted in=A0an in-flight failure.=A0 Those=A0will get a puc= ker factor (PF) rating of=A01.=A0 An example would be Ed's oil pump fai= lure due to a missing woodruff key.=A0
=A0
Incidents that happened in flight that resulted in=A0loss of=A0power, = but continued flight was possible,=A0will=A0receive a=A0PF rating of=A02.= =A0 Such as a turbo hose blowing off.=A0
=A0
Incidents that happened in the air that resulted in a precautionary la= nding will be rated=A0a PF=A03.
=A0
Incidents which happened in the air which=A0necessitated a forced land= ing (on or off field)=A0will get a=A0PR of 4.=A0
=A0
And finally, incidents which resulted in a crash and/or fatality will = be rated PF 5.
=A0
So, when reporting failures, please provide enough information for me = to determine the proper PF rating.=A0
=A0
Thanks,
Mark
=A0
On Mon, Apr 13, 2009 at 3:47 PM, David Leonard <= span dir=3D"ltr"><wdleonard@gmail= .com> wrote:
Mark,
=A0
Thanks for putting together this database.=A0 I agree with you and Al = G.=A0that we should keep it to issues with the engine and it's systems.= =A0 But I also agree with John and Al W. that we should somewhere include t= hings that probably would have caused an in-flight failure, especially when= found on pre-flight, run-up or take off roll.=A0 That is good stuff.=A0 No= t the idiot-pilot-owner stuff like forgetting to attach the return fuel lin= e, but the alternator bracket and PSRU issues etc - that could really help = someone.
=A0
Similarly, just because it is in flight does not make it newsworthy.= =A0 Like the intake hose blow offs that John and I have both experienced.= =A0 Sure, something happened and you are damn sure going to return to the a= irport and check it out even though you are pretty sure you know what happe= ned and it will not affect the safety of flight.=A0 OOps, didn't tighte= n that hose tight enough.
=A0
In other words, I think Johns incident #1 is far more significant than= incident #4.
=A0
Maybe to clarify:
=A0
#1 caused actual damage to the engine AND he NEEDED to land soon becau= se of oil loss.=A0 Power produced was less than normally aspirated power.= =A0 This is an interesting mechanical possibility (that a turbine blade som= ehow got BACK into the engine to bust the apex seal) and something importan= t to consider when designing a turbo install.=A0
=A0
#4 caused only a reduction=A0to normally aspirated power and a skipped= heart beat or two.=A0 No damage, no real need to land other than as a prec= aution.=A0 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=A0t= ight 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 <msteitle@gmail.com> wrote:
Dave,
=A0
I have decided to take Al's suggestion and=A0limit=A0the criteria = for the spreadsheet to basically include any in-flight system failure which= interrupts the planned flight and results in a premature landing.=A0 Based= on this, I will add #3 & #4 as well as the one=A0resulting from=A0a ru= ptured coolant hose.=A0
=A0
Mark S.

On Mon, Apr 13, 2009 at 7:55 AM, David Leonard <= span dir=3D"ltr"><wdleonard@gmail.com> wrote:
Mark, And did you get these?=A0 Added by me and John Slade under the w= rong thread title:


On Sun, Apr 12, 2009 at 5:15 PM, John Slade <jslade@canardaviation.com>= ; wrote:

Here's a few for the list, Mark,
1. Stock turbo bearings collapse= d & took out apex seal. Flew home at reduced power.
=A0
2. Fuel f= iler (sinstered bronze) looked clean but was restricting fuel flow. Flew ho= me on other tank.
=A0
3. Bad / intermittent contact on ignition timing sensor made engine = run rough. Landed normally and repaired.
=A0
4. Turbo hose blew off o= n take-off. Returned to land at reduced power.
John
------=A0
=A0=
Been there, done that. (the blown-off intake hose)
=A0
Also:

I have burned out 2 turbos.=A0 The first caused precautionary/urgent l= anding at an airport pending shutting off fuel flow to the turbo.=A0 The se= cond, I flipped a turbo oil shut off switch and flew 1000NM to get home.
=A0
Had a fuel pump die in flight, switched to the other and kept flying.(= soft failure)
I had a bad injector enable switch causing rough running during some p= hase one flying (after major change)...=A0 landed normally=A0

Forgot to re-connect fuel return line in engine bay after doing so= me work.=A0 dumped a couple gallons of fuel onto the running engine until I= smelled gas and shut down the engine.. (never left the parking space - but= it could have been really bad.

Cracked alternator mount bracket found on pre-flight during phase = one testing.=A0 Would have lost cooling and alternator if it happened now.<= /div>

PSRU sun gear pin broke from a backfire during run-up.=A0 Was able= to taxi back but would not have been able to fly.
=A0
This is good -= broke a coolant line in flight and smelled coolant...=A0 landed at nearby = airport and taxied up to restaurant with steam spewing out of the cowl.=A0 = Me and my buddy calmly walked into the restaurant and had breakfast.=A0 Aft= erward, we borrowed some tools and fixed the coolant line.=A0 Went back int= o the restaurant to ask for 2 pitchers of water to put in our plane.=A0 Con= tinued ski trip to Mammoth.=A0 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 <msteitle@gmail.com> wrote:
Thanks Bill,

With the ad= dition of Bill's exciting adventure, and one of my own, we're up to= 18 incidents in the database.=A0 These last two, along with Ed's brake= fire, and an oil coolant rupture, totals four incidents involving fires du= ring ground operations.=A0 Hopefully, everyone carries at least one fire ex= tinguisher in their airplane.

Mark S.

On Sun, Apr 12, 2009 at 2:56 PM, Bill Schertz <wschertz@comcast.net> wrote:
One other thing to watch out for -- Th= is occurred during ground testing, but if it had happened in the air it wou= ld have been a forced landing.
=A0
From=A0 my post of Feb. 8
Well, I haven't heard of this happ= ening before -- I was ground running my engine to=A0 tune it with the EM-2 = and EC-2.=A0 Ran for almost an hour, at various rpm's to change the man= ifold 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.
=A0
Engine was running good, took it up to= ~6000 rpm swinging a 76x76 Catto prop, when suddenly there was steam and f= luid on my windshield. Shut it down by killing power to the EC-2. Coolant e= verywhere.
=A0
Got out and looked to diagnose the pro= blem -- NOT my plumbing.=A0 A FREEZE PLUG in the iron housing had blown out= . Rapid coolant dump.
=A0
Secondary effect -- Since I shut down = suddenly from full tilt, either the proximity of the cowl to the exhaust, o= r possibly some of the coolant on the exhaust started a small fire on my co= wl. Put it out with extinguisher, but corner is charred.
=A0
Now in repair mode.
=A0
--------------------------
Update since this incident:=A0 All fre= eze 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.
=A0
Bill Schertz
KIS Cruiser #4045
N343BS
----- Original Message -----
Sent: Sunday, April 12, 2009 1:51 PM
Subject: [FlyRotary] Re: forced landings

Charlie,

That's a very good point.=A0 I'm try= ing to stay away from assigning a "cause" for whatever happened b= ecause I don't have all the facts.=A0 I have a field that says "Ex= planation of Failure".=A0 Hopefully, we can make statements as you sug= gest.=A0 Sometimes, even the FAA gets it wrong, like the time they attribut= ed the engine failure to the builder removing the oil injection pump.=A0 Al= so, I doubt that we could all agree on a "single cause" for each = failure.=A0 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.=A0= What I hope to accomplish is to point out areas where we need to be more c= areful 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

On Sun, Apr 12, 2009 at 11:46 AM, Charlie Englan= d <ceengland@bellsouth.net> wrote:
I think that it's just as important to understand the real cause o= f the failure. In the case of the plastic fuel flow sensor, it's highly= unlikely that use of the plastic sensor caused the failure; it was the use= of plastic in the wrong area without any protection. The homebuilder's= knee-jerk reaction is to say 'no plastic sensors because that one melt= ed', even though 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 w= ith fuel-soluble foam. Obviously, it failed, but only because of the wrong = application of products, not the products themselves.

Charlie

From: al wick <alwick@juno.com>=20

To: Rotary motors = in aircraft <flyrotary@lancaironline.net>
Sent: Sunday, April 12, 2009 10:13:00 AM
Subject: [FlyRotary] Re: fo= rced landings

Absolutely excellent Mark. I'd encourage you to get the year the inc= ident occured too. That will be your proof of reduced risk from things like= this newsgroup.

Avoid the black and white approach: forced landing or not forced. Becaus= e all things are shades of grey. Instead rate the severity. So it's a 1= 0 if the guy had to glide, it's=A0a 1 if he did precautionary landing. = If you also explain what happened, then a reader can easily tell you were o= bjective in 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 regist= ered with rotary engine in 2005. You can guess that equals 70 hours each. E= ven though it's a wild assed guess, it will still be excellent predicto= r 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: "T= hat same failure will happen to me". Particularly if you can look at &= quot;contributing factors". Then you can dramatically reduce personal = risk. Good example: We had that guy that installed plastic fuel flow sensor= in fuel line. It melted, he died. Tracy just reported hot exhaust caused f= uel to boil out of carb. These have the same=A0root cause. You don't wa= nt 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 he= re, 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 i= t. Your risk isn't some new cause. It's 1 of those 10 incidents tha= t you rationalized away, instead of saying:" that will happen to me to= o."

Good stuff.


-al wick
Cozy IV with 3.0 liter Subaru
230+ hrs tt from Portla= nd, Oregon

---------- Original Message ----------
From: Mark Stei= tle <msteitle@gm= ail.com>
To: "Rotary motors in aircraft" <flyrotary@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 tried to document the rotary incidents re= sulting in a forced landing?

Here's what I recall from memory, s= o 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 o= ut of spec)
=A0=A0=A0 1 forced landing due to improper assembly of engin= e (seal wedged between rotor & side housing)
=A0=A0=A0 1 forced land= ing on highway due to catastrophic overheating of engine
=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 f= or continued operation at reduced power, so we may or may not wish to inclu= de those here.=A0

While a number of these incidents date back quite a few years, and we h= ave made excellent progress, it says to me that we still have room for impr= ovement in the peripheral department.=A0 The good news is that out of all o= f the incidents listed above, none of them were caused by a true engine fai= lure.=A0 That's where the rotary has really earned my respect as a viab= le a/c engine.

Pay attention to the details!

Mark S.


On Sat, Apr 11, 2009 at 9:22 PM, Mike Wills <rv-4mike= @cox.net> wrote:
This has been an interesting thread. I= n the end, it doesnt really matter how many "major" parts you hav= e - even a minor failure can bring you down. While I believe the basic rota= ry engine itself is more fault tolerant than a recip, the peripherals used = in the typical rotary install are a lot more complex than a typical recip i= nstall. Since we rotary fliers dont have the benefit of 70 years worth of e= xperience flying behind the typical LyCon farm implement I think overall ou= r odds are considerably worse. Comes down to how well an individual enginee= r's his installation and there is a tremendous amount of variation here= .
=A0
The dependence on electronics in the t= ypical rotary install=A0 is a good example. I may be a little=A0sensitive t= o this issue since I've been trying to find an intermittent glitch (2 t= imes in 22 hours of engine testing).
=A0
Mike Wills
RV-4 N144MW=A0=A0
<= /div>
----- Original Message -----
Sent: Saturday, April 11, 2009 7:31 AM
Subject: [FlyRotary] Gary Casey was [FlyRotary] Re: Rotary Engine= s

Good analysis and logic, Gary.

=A0

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>

=A0

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.

=A0

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

=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.

=A0

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.

=A0

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= .

=A0

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:

=A0

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.

=A0

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.

=A0

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

=A0

=A0

Best Regards

=A0

Ed

=A0

=A0

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

http://www.eset.com/= =20



<= /blockquote>




--
David Leonard

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





--0015174bdeaa850b8f0467762803--