X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail06.syd.optusnet.com.au ([211.29.132.187] verified) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTPS id 984983 for flyrotary@lancaironline.net; Sat, 04 Jun 2005 23:14:32 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.187; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-73-161.dsl.nsw.optusnet.com.au [220.236.73.161]) by mail06.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j553DdX9028361 for ; Sun, 5 Jun 2005 13:13:41 +1000 Message-ID: <001501c5697d$4851dc40$a149ecdc@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: [valid] [FlyRotary] Re: [Fwd: COZY: Rotary risks] Date: Sun, 5 Jun 2005 13:18:44 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01C569D1.1989CDB0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0012_01C569D1.1989CDB0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, There's reasons for my enquiry, which involves castings for Aviation = use. My initial challenge was a multi use bellhousing to accommodate = Aussie PSRU and that of Tracy's unit. It doubles as a engine mount and accommodates 5 ( maybe more) starter = types and has to be light and strong. This requires strong thin wall = castings. Usually thin walled castings require pressure injection technology. This = is expensive and not cost effective because of the projected low demand, = probably one to 2 hundred (at most), in an initial 2/3 year period. I settled on sand cast technology, but because of the thinness of some = of the pattern, the aluminium is heated beyond it's recommended melting = temps, to allow for easier running into thinner area before the temps = are reduced by the sand casting process.=20 The initial trial did identify obvious porosity, throughout the pattern = although later trials, being carried out in the USA have yet to identify = any significant reduction in the projected strength requirements. My development partner in the States, Butch as he is affectionally know = throughout the Industry - is an Aviation Engineer. This design has been thoroughly tested on Finite Element Analysis, was = CAD designed, with myself making the pattern to exacting tolerances, due = to design restrictions and as Butch's exacting demands - he's a hard man = to please! Although this took some considerable time ( approx 12 months) the = pattern was completed and the prototypes done, by a very competent = foundry. If I can quote Butch's recent remarks to me " The Bellhousing arrived = safe and sound (Excellent Packaging)..... Very Robust to say the least, = should be able to handle 800hp at least. It has been Ultrasonically = analysed for density and voids, point load tested and torque twisting = along both the horizontal and vertical axis. Needless to say it passed with "Flying Colours!!=20 Do you see a pattern developing here? Research design and testing by = competent authority!! - even the packaging! To a unenlightened onlooker, on initially first seeing this bellhousing, = their response might be this design might not meet what we normally = accept as a bell-shaped design i.e. form not meeting design requirements = etc. etc. This is the type of development work carried out by many Experimental = designers - but not necessarily communicated to everyone to this degree. = I won't say this is true in all Rotary installations, but I will say = there is much in the way of skilled and talented builders involved in = the process of the Rotary development. The point I'm trying to make is, although I believe your risk analysis = is valid, I believe it is only valid when the information you base your = assessment is correct and complete. Often a valid assessment can be = completely turned on it's head when seemingly correct information is = found to be incomplete, therefore making the initial assessment = completely useless. I believe some assertions, on this discussion group, = have pointed to this possibility. BTW I'm on the look out for any good foundries around the East Coast = Nth of Washington, who could carry out this Bellhousing work ' Cost = Effectively', for the US market, if you know of any I would love to = hear about it. One of the problems on supply to the USA, is the 'Tyranny = of Distance'. George ( down under) I only did hydrogen experiments with permanent mold castings(thick = wall parts), so unsure if it applies to other types. But the experiments = were conclusive. Hydrogen was absolutely trivial. It was shrinkage = porosity which dominates the mechanical properties. Hydrogen porosity = develops round voids, shrinkage voids tear. =20 I suspect the myth continues regarding hydrogen. I did those = experiments over 10 years ago. It gave us huge advantage over = competition. We focused on methods to reduce shrinkage defects. Ended up = out performing our competition. That was a blast. I miss those = challenges. -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru = 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design = info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Sat, 4 Jun 2005 08:32:19 +1000 "George Lendich" = writes: I've had a look at Al Wicks approach and for me it leaves a lot of = unanswered questions. I have the benefit of being a ( now retired) = Government Logistics manager, trained in Quality Assurance, = Occupational Health and Safety, Risk management and of course = procurement. I had a good deal of experience within the medical = logistics field. This basic approach gives a basic guide provided you get your facts = straight and work on with the right information - I can't see this being = done with the Rotary. Perhaps he has done quite well with the Subaru - = who would know. Al if your on here would you please elaborate on the statement on = Aluminium - the information to me is that Hydrogen is indeed the major = problem with non- injection cast aluminium. Especially if it involves = elevated thin pour castings - the elevated temperature draws hydrogen = from the air and releases it as bubbles in the aluminium, the higher the = humidity the greater the chace of Hydrogen porosity. As we all know porosity is the primary cause of strength reduction = in a cast aluminium piece. I understand there are other causes of = porosity, but am unsure of what they all are. George ( down under) Ernest Christley wrote: Jim, Al is not following his own process (I think I alluded to = this previously). First, you have to ask, "How many failures have = accurred due to a faulty CAS?" That's a fair question. Do you know? = Does anyone? If so, Who? Seems there was a thread around that just a = month or two ago. Intuitively, I would say that CAS would be a single = point of failure, important enough to be remediated. The text below is = copy and pasted from = http://www.maddyhome.com/canardpages/pages/alwick/risk.html The key = phrase is the last sentence.=20 We are going to do an FMEA. What is the goal we are trying to = achieve with this process? It's to make sure we place our efforts on the = facets which need it. Put another way, it's making sure we don't waste = time and effort on insignificant items, while ignoring the truly = important items.=20 There are only three pieces to the puzzle. In the case of CAS = (just my guess) 1) If the component failed, how serious would that effect the = airplane? catastrophic 2) What is the probability of the component failing? = Undetermined. Start with doing some research at NAPA et al and repair = shops around how many they sell. 3) What is the likelihood that you would notice the problem = before failure? I'd guess very VERY remote. You may have heard statements like "You have to replace = component x on your engine before installing into an airplane because it = represents a single point failure". Meaning that if x fails, there is no = backup component. That statement is not meaningful until you assess all = three questions above.=20 Exactly. Al's question is "... to what extent are "we" using = his methodology. My own guess would be "not much ...". Single point(s) = of failure in Tracy's ignition (and fuel control) systems - if there are = any - would be a case in point. As would redundant fuel pumps powered = by a single source, and charging systems that are not sufficiently = redundant and with appropriate indicators. If one DOES have a single = point of failure (and there are inevitably many) we must be sure that = that component is sufficiently robust to give us all confidence that it = will NOT fail. >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0012_01C569D1.1989CDB0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Al,
There's reasons for my enquiry, which involves = castings for=20 Aviation use. My initial challenge was a multi use bellhousing to=20 accommodate Aussie PSRU and that of Tracy's unit.
It doubles as a engine mount and accommodates 5 = ( maybe=20 more) starter types and has to be light and strong. This requires strong = thin=20 wall castings.
Usually thin walled castings require pressure = injection=20 technology. This is expensive and not cost effective = because of the projected low demand, probably one to 2 hundred (at = most), in an=20 initial 2/3 year period.
I settled on sand cast technology, but because = of the=20 thinness of some of the pattern, the aluminium is heated beyond it's = recommended=20 melting temps, to allow for easier running into thinner area before the = temps=20 are reduced by the sand casting process. 
 
The initial trial did identify obvious porosity, = throughout=20 the pattern although later trials, being carried out in the USA have yet = to=20 identify any significant reduction in the projected strength=20 requirements.
 
My development partner in the States, Butch as he is = affectionally know throughout the Industry - is an Aviation=20 Engineer.
This design has been thoroughly tested on Finite = Element=20 Analysis, was CAD designed, with myself making the pattern to exacting=20 tolerances, due to design restrictions and as Butch's exacting demands - = he's a=20 hard man to please!
 
Although this took some considerable time ( approx = 12 months)=20 the pattern was completed and the prototypes done, by a very competent=20 foundry.
 
If I can quote Butch's recent remarks to me = " The=20 Bellhousing arrived safe and sound (Excellent Packaging)..... Very = Robust to say=20 the least, should be able to handle 800hp at least. It has been = Ultrasonically=20 analysed for density and voids, point load tested and = torque twisting along=20 both the horizontal and vertical axis.
Needless to say it passed with "Flying=20 Colours!! 
 
Do you see a pattern developing here? Research = design and=20 testing by competent authority!! - even the packaging!
 
To a unenlightened onlooker, on initially first = seeing this=20 bellhousing, their response might be this design might not meet = what we=20 normally accept as a bell-shaped design i.e. form not meeting design=20 requirements etc. etc.
 
This is the type of development work carried out by = many=20 Experimental designers - but not necessarily communicated to = everyone to=20 this degree. I won't say this is true in all Rotary installations, but I = will=20 say there is much in the way of skilled and talented builders involved = in the=20 process of the Rotary development.
 
The point I'm trying to make is, although I believe = your risk=20 analysis is valid, I believe it is only valid when the information you = base your=20 assessment is correct and complete. Often a valid assessment can be = completely=20 turned on it's head when seemingly correct information is found to be=20 incomplete, therefore making the initial assessment completely useless. = I=20 believe some assertions, on this discussion group, have pointed to this=20 possibility.
 
BTW I'm on the look out for any good foundries=20 around  the East Coast Nth of Washington, who could carry out this=20 Bellhousing work ' Cost Effectively',  for the US market, if = you know=20 of any I would love to hear about it. One of the problems on supply = to the=20 USA, is the 'Tyranny of Distance'.
George ( down under)
 
 
I only did hydrogen experiments with permanent = mold=20 castings(thick wall parts), so unsure if it applies to other types. = But the=20 experiments were conclusive. Hydrogen was absolutely trivial. It was = shrinkage=20 porosity which dominates the mechanical properties. Hydrogen porosity = develops=20 round voids, shrinkage voids tear.  
 
I suspect the myth continues regarding hydrogen. I did those = experiments=20 over 10 years ago. It gave us huge advantage over competition. We = focused on=20 methods to reduce shrinkage defects. Ended up out performing our = competition.=20 That was a blast. I miss those challenges.
 

-al wick
Artificial intelligence in cockpit, Cozy IV = powered by=20 stock Subaru 2.5
N9032U 200+ hours on engine/airframe from = Portland,=20 Oregon
Prop construct, Subaru install, Risk assessment, Glass panel = design=20 = info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
=
 
 
On Sat, 4 Jun 2005 08:32:19 +1000 "George Lendich" <lendich@optusnet.com.au>=20 writes:
I've had a look at Al Wicks approach and for me = it leaves=20 a lot of unanswered questions. I have the benefit of being a ( now = retired)=20 Government Logistics manager, trained in Quality = Assurance, =20 Occupational Health and Safety, Risk management and of course = procurement. I=20 had a good deal of experience within the medical logistics=20 field.
This basic approach gives a basic guide = provided you=20 get your facts straight and work on with the right information - I = can't see=20 this being done with the Rotary. Perhaps he has done quite well with = the=20 Subaru - who would know.
 
Al if your on here would you please elaborate on = the=20 statement on Aluminium - the information to me is that Hydrogen is = indeed=20 the major problem with non- injection cast aluminium. = Especially if it=20 involves elevated thin pour castings - the elevated temperature = draws=20 hydrogen from the air and releases it as bubbles in the aluminium, = the=20 higher the humidity the greater the chace of Hydrogen = porosity.
As we all know porosity is the primary cause of = strength=20 reduction in a cast aluminium piece. I understand there are other = causes of=20 porosity, but am unsure of what they all are.
 
George ( down under)
Ernest=20 Christley wrote:
Jim, Al = is not=20 following his own process (I think I alluded to this = previously). First,=20 you have to ask, "How many failures have accurred due to a = faulty=20 CAS?"  That's a fair question.  = Do you=20 know?  Does anyone?  If so, Who?  Seems there was = a=20 thread around that just a month or two ago.   Intuitively, = I would=20 say that CAS would be a single point of failure, important = enough to be=20 remediated.  The text below is copy and pasted = from  http= ://www.maddyhome.com/canardpages/pages/alwick/risk.html=20 The key phrase is the last sentence.

We are going to do = an FMEA.=20 What is the goal we are trying to achieve with this process? = It=92s to=20 make sure we place our efforts on the facets which need it. Put = another=20 way, it=92s making sure we don=92t waste time and effort on = insignificant=20 items, while ignoring the truly important items.

There = are only=20 three pieces to the puzzle.   In = the case=20 of CAS (just my guess)

1) If the component failed, = how=20 serious would that effect the airplane?  catastrophic

2) What is the = probability of=20 the component failing? Undetermined.  = Start=20 with doing some research at NAPA et al and repair shops around = how many=20 they sell.

3) What is the likelihood that you = would notice=20 the problem before failure?  I'd = guess very=20 VERY remote.

You may have heard statements like = =93You have=20 to replace component x on your engine before installing into an = airplane=20 because it represents a single point failure=94. Meaning that if = x fails,=20 there is no backup component. That statement is not meaningful = until you=20 assess all three questions above.
Exactly. =20 Al's question is "... to what extent are "we" using his=20 methodology.  My own guess would be "not much ...".  = Single=20 point(s) of failure in Tracy's ignition (and fuel control) = systems - if=20 there are any - would be a case in point.  As would = redundant fuel=20 pumps powered by a single source, and charging systems that are = not=20 sufficiently redundant and with appropriate indicators.  If = one=20 DOES have a single point of failure (and there are inevitably = many) we=20 must be sure that that component is sufficiently robust to give = us all=20 confidence that it will NOT fail.

>>  Homepage:  http://www.flyrotary.com/

>>  Archive:   =
http://lancaironline.net/lists/flyrotary/List.html
 
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