X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.3.3) with ESMTP id 4151459 for flyrotary@lancaironline.net; Wed, 03 Mar 2010 20:01:33 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.0 c=1 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=pedpZTtsAAAA:8 a=LZ2fO-2TAAAA:8 a=CGTMIkxhI6yssuEPgKYA:9 a=tn70AXqe1d89eScI2N4A:7 a=QBUgNfNCm0TZPPt9NKe-Q9QwS2EA:4 a=1vhyWl4Y8LcA:10 a=EzXvWhQp4_cA:10 a=eJojReuL3h0A:10 a=tb9jDWrh1823m0AN:21 a=wLm2QxZegky7xDGD:21 a=SSmOFEACAAAA:8 a=oCqK0ZozkkCB3GZ5ckMA:9 a=XEgOfFRKxGJXtiiEezcA:7 a=qdWMoDhP6cCLyVoLDmaAZ9A2Y4EA:4 a=LRpBhGf8z0-3uw-o:21 a=DdnMjKr0BKLTFsKd:21 X-Cloudmark-Score: 0 X-Originating-IP: 75.191.186.236 Received: from [75.191.186.236] ([75.191.186.236:4335] helo=computername) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id F8/87-08021-A460F8B4; Thu, 04 Mar 2010 01:00:59 +0000 From: "Ed Anderson" Message-ID: To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: single rotor Date: Wed, 3 Mar 2010 20:01:02 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0082_01CABB0C.40AFDFB0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: Acq7AwvBgt/GWUcmQjKuz5pTCnVwxQAI185A In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0082_01CABB0C.40AFDFB0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Humm, I recall that accident as I had exchanged e mails with Parkman - he was the guru of converting auto CPUs to work in aircraft. But, while apparently a whiz at the electronic end of things - less so on the mechanical side. As I recall the accident which took his life, he had set his prop (adjustable) to give him the maximum rpm which of course turned out to be the minimum prop pitch (less load on the engine more rpm). This reduced the thrust available because with the almost flat spinning prop blades the Dv imparted to the air was much smaller than it would have been with less rpm but more pitch. As a results, his long EZ (I believe) accelerated sufficient to gain airspeed to lift off in ground effect - but never enough to climb to altitude - Steve unfortunately impacted a tall catus plant and was killed. So maximum engine rpm does not of itself indicate maximum thrust. A balance between generating power (engine rpm) and transferring that energy to accelerating the air is what we are looking for. Too little rpm (power) and thrust goes down - too much rpm but too little Dv and thrust goes down. Like just about everything in this hobby, its about balancing conflicting parameters. That's my take on it. 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 Tracy Crook Sent: Wednesday, March 03, 2010 1:53 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: single rotor "it takes 1.6 times as much horsepower to develop 1.18 times as much static thrust! " I didn't study the site but just this statement is ludicrous. It takes NO horsepower to generate static thrust. A freek'n spring will make static thrust. For our purposes, static thrust is not a useful term and sometimes a dangerous one. Steve (?) Parkman died many years ago mainly because he set his engine and prop up for best static thrust on his airplane prior to his first flight. Tracy Crook On Wed, Mar 3, 2010 at 9:18 AM, Bill Bradburry wrote: Looking at the two sizes of the engine, it takes 1.6 times as much horsepower to develop 1.18 times as much static thrust! Somehow this does not compute for me..I always doubt the performance figures in a sales presentation and when they don't make sense to me...??? Bill B (hoping this generates an educational experience for me :>) ) _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills Sent: Tuesday, March 02, 2010 11:10 PM To: Rotary motors in aircraft Subject: [FlyRotary] single rotor A friend of mine flies a powered paraglider (PPG). He attended a flyin last month and saw this: http://www.flycyclone.com/range/category/294cc_Everest/ It's a single rotor liquid cooled rotary and available in several different displacements. Do a little web surfing and you'll find some pretty cool videos of guys flying PPGs powered by this. Mike Wills ------=_NextPart_000_0082_01CABB0C.40AFDFB0 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Humm, I recall that accident as I = had exchanged e mails with Parkman – he was the guru of converting = auto CPUs to work in aircraft.  But, while apparently a whiz at the = electronic end of things – less so on the mechanical = side.

 

As I recall the accident which took = his life, he had set his prop (adjustable) to give him the maximum rpm which = of course turned out to be the minimum prop pitch (less load on the engine = more rpm).  This reduced the thrust available because with the almost = flat spinning prop blades the = Dv imparted to the = air was much smaller than it would have been with less rpm but more pitch.  = As a results, his long EZ (I believe) accelerated sufficient to gain airspeed = to lift off in ground effect – but never enough to climb to altitude = – Steve unfortunately impacted a tall catus plant and was = killed.

 

So maximum engine rpm does not of = itself indicate maximum thrust.  A balance between generating power = (engine rpm) and transferring that energy to accelerating the air is what we are = looking for.  Too little rpm (power) and thrust goes down – too much = rpm but too little D<= font size=3D2 color=3Dnavy face=3DArial>v and thrust goes down.  Like just about everything in = this hobby, its about balancing conflicting = parameters.

 

That’s my take on = it.

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Wednesday, March = 03, 2010 1:53 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = single rotor

 

"it takes 1.6 times as much horsepower to develop 1.18 = times as much static thrust! "

 

I didn't study the site but just this statement is = ludicrous.  It takes NO horsepower to generate static thrust.  A freek'n spring = will make static thrust.  For our purposes, static thrust is not a useful = term and sometimes a dangerous one.  Steve (?) Parkman  died many = years ago mainly because he set his engine and prop up for = best static thrust on his airplane = prior to his first flight.

 

Tracy = Crook

On Wed, Mar 3, 2010 at 9:18 AM, Bill Bradburry <bbradburry@bellsouth.net>= wrote:

Looking at the two sizes of the engine, it takes 1.6 times as much horsepower to develop = 1.18 times as much static thrust!  Somehow this does not compute for me….I always doubt the performance figures in a sales presentation = and when they don’t make sense to = me…..???

 

Bill = B (hoping this generates an educational experience for me  :>)  = )

 

From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike = Wills
Sent: Tuesday, March 02, = 2010 11:10 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] = single rotor

A friend of mine flies a powered paraglider (PPG). He attended a flyin last month = and saw this:

 

 

It's a single rotor liquid cooled rotary and available in several different displacements. Do a little web surfing and you'll find some pretty cool = videos of guys flying PPGs powered by this.

 

Mike Wills

 

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