X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qw-out-2122.google.com ([74.125.92.25] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3524867 for flyrotary@lancaironline.net; Tue, 03 Mar 2009 08:24:39 -0500 Received-SPF: pass receiver=logan.com; client-ip=74.125.92.25; envelope-from=msteitle@gmail.com Received: by qw-out-2122.google.com with SMTP id 8so2125040qwh.25 for ; Tue, 03 Mar 2009 05:24:02 -0800 (PST) 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=jvKuELTRa3cPA+aYQ46ec3y0JKs3VsJrkQZ6QlA5m4Q=; b=OgyDk260UptsLuzQwF9MO5kfNZ2PhEPqCo0wDLJ7UsPXhcOTIlj8arIcMwIE4+/OkL D48e5VoZ2K7iYCdFU27UwNj331wPTtMFuawiNV4jmKbGbpjHMR7bmvM0Zhnof3JQAZq8 LGaRPgtbXQZVk4mYFdu3YrZfVL3se5d/l2qcU= 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=Nb5tYzFoFeqBaXqYAxzvkJRgXaxudB+ZUEDhYaJAfiuFahFTNehFWdzq/jclVbrLBk QsMWqxD7oENCVhs0KrWrbkuLVBs0S5eyBQl9Aa5f/Ad8RepsKvzUIa/l5o2PIeHVzvwk 4J1RYnJmf5rAUrjEvnh16tK4jqaqBLnv5XS/o= MIME-Version: 1.0 Received: by 10.224.60.66 with SMTP id o2mr9611957qah.2.1236086642418; Tue, 03 Mar 2009 05:24:02 -0800 (PST) In-Reply-To: References: Date: Tue, 3 Mar 2009 07:24:02 -0600 Message-ID: <5cf132c0903030524v3a3a4d7o92cf54e0f37b9b29@mail.gmail.com> Subject: Re: [FlyRotary] Re: Questions on buying a rotary plane From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015175cdf523ba3e4046436d933 --0015175cdf523ba3e4046436d933 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit William, I'll throw my 2 cents worth in here. Regardinging fuel burn, I'm not overly concerned with bsfc, although its not that bad if you're running EFI. What we're really interested in is cost per mile. I have burned nothing but mogas in my 3-rotor Lancair. The last time I purchased fuel, it was $1.65/gallon. My N/A 3-rotor burns between 10 and 11 gph at around 20" MAP. So, it will cost me somewhere around $16.50 - $18.15/hr to fly. Other Lancair ES's are running IO-540's, or some derivative of the "540". From what I hear, they burn between 12 - 15 gph. With the cost of 100LL running around $4/gallon, that would cost between $48 - $60/hr in fuel. So, figuring cost per mile, I don't see how a Lycoming could come close to matching a rotary. The fuel savings alone will more than cover the cost of an overhaul. And hope the Lycoming doesn't burn a valve, or any number of other common ailments which can take a serious bite out of your checkbook. Most of the things that break on a piston engine aren't even present on the rotary. If it ain't there, it can't break. So, would I use a rotary if I were to do it over, yes, absolutely! Mark S. On Mon, Mar 2, 2009 at 11:31 PM, William Wilson wrote: > I have not found an accomodating A&P but I attribute that to the fact that > I have not looked yet. Given that I live in Seattle I am pretty sure I can > find one. Seattle is crawling (fluttering?) with homebuilt planes. If > anyone has suggestions, I am listening, but I had not started searching yet. > > Plan is not to take apart a perfectly good flying plane to change the > engine, but ideally to get one with a rotary in it already, or replace only > at overhaul time. In each case I save as much on the cheaper engine as I > would lose on resale value... and if the plane has the rotary in it to start > with, I get to pay the lower price up front too, which makes price > difference just plain better. > > For efficiency what I said was that homebuilt planes are more efficient > than factory built, not that rotary are more efficient than Lycoming, though > in that case it should be quite close. Bad fuel economy of rotary engine is > overstated, economy is comparatively bad at low power & RPM but at high > power it is not bad at all. As long as you are not turbocharged, you can > run much leaner than a piston engine, making up for less efficient > combustion chamber shape. Rotary BSFC in the lab has gone as low as .375 > (for renesis), and .44-.46 measured in real world racing applications even > with traditional type engine. So I think I would not see a significant > difference in fuel economy between rotary and piston. Weight & drag of the > plane it is in will matter more. > > In any case all advice is welcome, even dissenting opinions ;) > > On Mon, Mar 2, 2009 at 8:12 PM, Mike Wills wrote: > >> William, >> >> I highly recommend you check around to make sure you can find an A&P who >> will do a condition inspection with the rotary engine installed BEFORE you >> commit. Many A&Ps I've talked to dont want anything to do with Experimentals >> let alone an engine that looks nothing like what they are used to. There's >> simply too much potential liability (real or perceived) to go out on a limb >> like that. The A&P who used to do the condition inspection on the RV-6A I >> used to own (Lycoming powered) was willing to do it because the RV structure >> is similar to typical spam cans. He wont have anything to do with wet layup >> homebuilts (EZs, Cozys, etc...). He doesnt even like doing annuals on >> Diamond aircraft with the Rotax 912/914 and they are certified. >> >> If you buy a flying homebuilt that is Lyc or Continental powered, before >> you convert it to rotary power seriously think about what you are doing to >> the resale value - if you could ever sell it that is. My guess is that >> you'll give up at least $10,000 in resale value, maybe much more. No big >> deal if you plan on keeping it for life. >> >> I dont know where you got the idea that rotaries are more fuel efficient. >> Lycosaurs/Continentals typically have BSFCs in the low .40s. The commonly >> accepted number for a rotary is about .50. Some here seem to do better, >> others worse. With a grand total of 2 hours on my rotary I cant say what my >> experience will be but hope its close to the Lyc I used to fly. >> >> Finally dont underestimate the effort required to make the change. I >> started building my RV-4 in late 1995. The airframe was essentially done in >> 2000. My first flight was last month. Granted I took longer than many and >> much of the trouble came from my desire to eliminate the cowl cheeks on an >> already cramped engine compartment. But thats eight years of tinkering to >> get the engine installed and running to the point where I had enough >> confidence in it to fly it. >> >> Not trying to discourage you, but go into this with eyes wide open. >> >> Mike Wills >> RV-4 N144MW >> - Show quoted text - >> >> >> >> ----- Original Message ----- >> *From:* William Wilson >> *To:* Rotary motors in aircraft >> *Sent:* Sunday, March 01, 2009 7:46 PM >> *Subject:* [Norton AntiSpam] [FlyRotary] Re: Questions on buying a rotary >> plane >> >> This is great news. Thanks Charlie and Bob :) >> >> On Sun, Mar 1, 2009 at 7:34 PM, Charlie England wrote: >> >>> William Wilson wrote: >>> >>>> I am in the market for a plane and would prefer a rotary-powered, as I >>>> have lots of experience working with rotary engines. As a bonus, homebuilt >>>> planes all seem to get about twice as much fuel economy as factory built >>>> planes. So that is nice too. I know there are a few rotary powered planes >>>> available for sale, but not too many. >>>> >>>> I have neither the time nor desire to build my own plane, so my question >>>> is more about maintenance and inspections. I'm not an official A&P and I >>>> don't know if I will be able to find an A&P to work on a home built plane >>>> with a car engine in it! I am happy to do engine maintenance, but am not >>>> entirely clear on the legality of it, since I would not be the original >>>> builder. >>>> >>>> Similarly when it is eventually time for an engine rebuild, would I be >>>> able to remove the engine, take it down to Atkins (who are not far from me) >>>> and have them rebuild it, or rebuild it myself, and then reinstall it, and >>>> find an A&P to just sign off on the work? >>>> >>>> Plan B is to buy whatever plane even if it has a Lycosaurus, but when >>>> time for overhaul comes, get rid of the Lycoming and replace it with a >>>> rotary. Thought in this case is to get the rotary tuned, a little broken in >>>> and running on a stand in the hangar in advance, so that when the time comes >>>> to do the swap it can be done with a minimum of downtime. (I know it cannot >>>> really be tuned for altitude in this way but it is better than nothing!). >>>> But again, the fact that I would not be the original builder makes me worry >>>> about legalities. I have heard that this has been done so question is more >>>> about the how. >>>> >>>> I do not really understand all the law involved and hopefully somebody >>>> here can help. Thanks! >>>> >>> >>> I can't speak with authority, but I can speak from experience. >>> >>> Experimental homebuilts can be maintained or modified by anyone. No FAA >>> blessings required. Annual condition inspections must be performed by either >>> the holder of the 'repairman's certificate' (only available to the builder >>> of record) or by the holder of an A&P ticket (no IA required). >>> >>> Once the airworthiness certificate is awarded, *anyone* can do any >>> maintenance, repairs, modifications etc desired. The post-modification >>> requirements vary somewhat from plane to plane depending on when the a/w was >>> issued, but in general terms, you notify the FAA in writing that major mods >>> were made, ask for a defined test area, make a log entry detailing the >>> return to 'phase one' testing, fly test flights for (typically) 5 hours, >>> then make another log entry saying that the plane has been tested with the >>> mods & is being returned to 'phase two' (normal operational) status. >>> >>> 'Major modification' isn't clearly defined, but if you have to ask, it's >>> major. :-) >>> >>> The availability of an A&P to sign off condition inspections is all over >>> the map (literally). It's never been a problem for me, but in some parts of >>> the country people can't find an A&P who will sign off *any* homebuilt, no >>> matter what engine. If you have that problem, get to know the guys who sign >>> off the crop dusters in your area. >>> >>> Hope that helps.... >>> >>> Charlie >>> >>> >>> >>> >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: >>> http://mail.lancaironline.net:81/lists/flyrotary/List.html >>> >> >> > --0015175cdf523ba3e4046436d933 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
William,
=A0
I'll throw my 2 cents worth in here.=A0 Regardinging fuel burn, I&= #39;m not overly concerned with bsfc, although its not that bad if you'= re running EFI.=A0 What we're really interested in is cost per mile.=A0= I have burned nothing but mogas in my 3-rotor Lancair.=A0 The last time I = purchased fuel, it was $1.65/gallon.=A0=A0My N/A 3-rotor=A0burns between 10= and 11 gph at around 20" MAP.=A0 So, it will cost me somewhere around= $16.50 - $18.15/hr=A0to fly.=A0 Other Lancair ES's are running IO-540&= #39;s, or some derivative of the "540".=A0 From what I hear, they= burn between 12 - 15 gph.=A0 With the cost of 100LL running around $4/gall= on, that=A0would cost between=A0$48 - $60/hr in fuel.=A0=A0So, figuring cos= t per mile, I don't see how a Lycoming could come close to matching a r= otary.=A0=A0The fuel savings alone will more than cover the cost of an over= haul.=A0
=A0
And hope the Lycoming doesn't=A0burn a valve, or any number of oth= er common ailments which=A0can=A0take a serious bite out of your checkbook.= =A0=A0Most of the things that break on a piston engine aren't even pres= ent on the rotary.=A0 If it ain't there, it can't break.
=A0
So, would I use a rotary if I were to do it over, yes, absolutely!
=A0=A0=A0
Mark S.
On Mon, Mar 2, 2009 at 11:31 PM, William Wilson = <fluffysheap@= gmail.com> wrote:
I have not found an accomodating= A&P but I attribute that to the fact that I have not looked yet.=A0 Gi= ven that I live in Seattle I am pretty sure I can find one.=A0 Seattle is c= rawling (fluttering?) with homebuilt planes.=A0 If anyone has suggestions, = I am listening, but I had not started searching yet.

Plan is not to take apart a perfectly good flying plane to change the e= ngine, but ideally to get one with a rotary in it already, or replace only = at overhaul time.=A0 In each case I save as much on the cheaper engine as I= would lose on resale value... and if the plane has the rotary in it to sta= rt with, I get to pay the lower price up front too, which makes price diffe= rence just plain better.

For efficiency what I said was that homebuilt planes are more efficient= than factory built, not that rotary are more efficient than Lycoming, thou= gh in that case it should be quite close.=A0 Bad fuel economy of rotary eng= ine is overstated, economy is comparatively bad at low power & RPM but = at high power it is not bad at all.=A0 As long as you are not turbocharged,= you can run much leaner than a piston engine, making up for less efficient= combustion chamber shape.=A0 Rotary BSFC in the lab has gone as low as .37= 5 (for renesis), and .44-.46 measured in real world racing applications eve= n with traditional type engine.=A0 So I think I would not see a significant= difference in fuel economy between rotary and piston.=A0 Weight & drag= of the plane it is in will matter more.

In any case all advice is welcome, even dissenting opinions ;)

On Mon, Mar 2, 2009 at 8:12 PM, Mike Wills <rv-4mike@cox.= net> wrote:
William,
=A0
=A0I highly recommend you check around= to make sure you can find an A&P who will do a condition inspection wi= th the rotary engine installed BEFORE you commit. Many A&Ps I've ta= lked to dont want anything to do with Experimentals let alone an engine tha= t looks nothing like what they are used to. There's simply too much pot= ential liability (real or perceived) to go out on a limb like that. The A&a= mp;P who used to do the condition inspection on the RV-6A I used to own (Ly= coming powered) was willing to do it because the RV structure is similar to= typical spam cans. He wont have anything to do with wet layup homebuilts (= EZs, Cozys, etc...). He doesnt even like doing annuals on Diamond aircraft = with the Rotax 912/914 and they are certified.
=A0
=A0If you buy a flying homebuilt that = is Lyc or Continental powered, before you convert it to rotary power seriou= sly think about what you are doing to the resale value - if you could ever = sell it that is. My guess is that you'll give up at least $10,000 in re= sale value, maybe much more. No big deal if you plan on keeping it for life= .
=A0
=A0I dont know where you got the idea = that rotaries are more fuel efficient. Lycosaurs/Continentals typically hav= e BSFCs in the low .40s. The commonly accepted number for a rotary is about= .50. Some here seem to do better, others worse. With a grand total of 2 ho= urs on my rotary I cant say what my experience will be but hope its close t= o the Lyc I used to fly.
=A0
=A0Finally dont underestimate the effo= rt required to make the change. I started building my RV-4=A0 in late 1995.= The airframe was essentially done in 2000. My first flight was last month.= Granted I took longer than many and much of the trouble came from my desir= e to eliminate the cowl cheeks on an already cramped engine compartment. Bu= t thats eight years of tinkering to get the engine installed and running to= the point where I had enough confidence in it to fly it.
=A0
=A0Not trying to discourage you, but g= o into this with eyes wide open.
=A0
Mike Wills
RV-4 N144MW
- Show quoted text -
=A0
=A0
----- Original Message -----
To: Rotary motors in aircraft
Sent: Sunday, March 01, 2009 7:46 PM
Subject: [Norton AntiSpam] [FlyRotary] Re: Questions on buying a = rotary plane

This is great news.=A0 Thanks Charlie and Bob :)

On Sun, Mar 1, 2009 at 7:34 PM, Charlie England = <ceengland@bellsouth.net> wrote:
William Wilson wrote:
I am in the market f= or a plane and would prefer a rotary-powered, as I have lots of experience = working with rotary engines. =A0As a bonus, homebuilt planes all seem to ge= t about twice as much fuel economy as factory built planes. =A0So that is n= ice too. =A0I know there are a few rotary powered planes available for sale= , but not too many.

I have neither the time nor desire to build my own plane, so my questio= n is more about maintenance and inspections. =A0I'm not an official A&a= mp;P and I don't know if I will be able to find an A&P to work on a= home built plane with a car engine in it! =A0I am happy to do engine maint= enance, but am not entirely clear on the legality of it, since I would not = be the original builder.

Similarly when it is eventually time for an engine rebuild, would I be = able to remove the engine, take it down to Atkins (who are not far from me)= and have them rebuild it, or rebuild it myself, and then reinstall it, and= find an A&P to just sign off on the work?

Plan B is to buy whatever plane even if it has a Lycosaurus, but when t= ime for overhaul comes, get rid of the Lycoming and replace it with a rotar= y. =A0Thought in this case is to get the rotary tuned, a little broken in a= nd running on a stand in the hangar in advance, so that when the time comes= to do the swap it can be done with a minimum of downtime. =A0(I know it ca= nnot really be tuned for altitude in this way but it is better than nothing= !). =A0But again, the fact that I would not be the original builder makes m= e worry about legalities. =A0I have heard that this has been done so questi= on is more about the how.

I do not really understand all the law involved and hopefully somebody = here can help. =A0Thanks!

I can't speak with = authority, but I can speak from experience.

Experimental homebuilts = can be maintained or modified by anyone. No FAA blessings required. Annual = condition inspections must be performed by either the holder of the 're= pairman's certificate' (only available to the builder of record) or= by the holder of an A&P ticket (no IA required).

Once the airworthiness certificate is awarded, *anyone* can do any main= tenance, repairs, modifications etc desired. The post-modification requirem= ents vary somewhat from plane to plane depending on when the a/w was issued= , but in general terms, you notify the FAA in writing that major mods were = made, ask for a defined test area, make a log entry detailing the return to= 'phase one' testing, fly test flights for (typically) 5 hours, the= n make another log entry saying that the plane has been tested with the mod= s & is being returned to 'phase two' (normal operational) statu= s.

'Major modification' isn't clearly defined, but if you have= to ask, it's major. :-)

The availability of an A&P to sign = off condition inspections is all over the map (literally). It's never b= een a problem for me, but in some parts of the country people can't fin= d an A&P who will sign off =A0*any* homebuilt, no matter what engine. I= f you have that problem, =A0get to know the guys who sign off the crop dust= ers in your area.

Hope that helps....

Charlie=20



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