Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 819247 for flyrotary@lancaironline.net; Thu, 24 Mar 2005 16:13:52 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-185-127.carolina.rr.com [24.74.185.127]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j2OLD3Y5003634 for ; Thu, 24 Mar 2005 16:13:04 -0500 (EST) Message-ID: <003001c530b6$48af5b40$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" Subject: Bad Day Good Day Non-Rotary Date: Thu, 24 Mar 2005 16:13:10 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01C5308C.5F8F51F0" 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 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_002D_01C5308C.5F8F51F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Some days are bad, some days are good and some days have a bit of both. = I went out to the hangar around 1000 to hook up my new digital Fuel = Monitoring system. The Bad news is it read the first pulse and froze = (more on this later), so I was a bit discouraged, though it might be the = EFI pulse might be dirty compared to the laboratory pulse I had been = using to test the unit. Figured I would have to haul my oscilloscope = out to the hangar tomorrow to see what the EFI pulse train actually = looked like. But, while scratching my head, my two new next-door hangar neighbors = showed up to fly their Kobe Ultralight. These are both older airline = pilots (one retired) who decided to fly utralights - without any lessons = of course. But, nice guys just the same. The first flight made about = two weeks ago ended up with one of the landing struts bent from dropping = it in a bit high. =20 Today they were back for another try. Number one takes off and it = sounds like to me that he is not making anywhere near full power. He = flys around the pattern a couple of times making passes at the runway = and finally sets it down with about a 2 foot drop - not too pretty but = respectable. He then is trying to talk his buddy into taking it up - as = they are discussing how it handles, I over hear him make a comment that = at full throttle the power fades and you have to pull it back to around = 4500 rpm ( the max he has reached) to get the power back. Well, I know nothing about rotax engines but that sounded like fuel = starvation at higher power settings. I asked what type fuel pump they = had and it turns out it is a diaphragm type driven by pulsation's from = the engine via a tube. Sure enough as I looked it over, I found that = the tube from the engine to the pump that provided the suction pulses to = work the diaphragm was crimped almost shut near the pump where it was = difficult to see. Clearly not a good condition, I point this out to = them and they rapidly put on a new tube. Fired it up and got almost 6000 rpm on the ground. Took off and look = like he was going straight up - a marked difference in performance. = Don't know if this condition would have resulted in an accident - but = clearly not a good situation. So they day turned out not so bad after all. Then I got home hooked up = the EFI monitor and it wouldn't work there either !!!!! Turns out I changed ONE line of code this morning before taking it out = and had not bothered to check it on the laboratory pulse meter. I mean = it was a very simple change {:>). It didn't work on it any better back = at home than it did on the aircraft. But, it was a relief to know it = was a simply code screw up. Eliminated that line of code and all is = back working. So what started out to be a bad day (relatively speaking) ended up = pretty nice. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ------=_NextPart_000_002D_01C5308C.5F8F51F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Some days are bad, some days are good = and some days=20 have a bit of both.  I went out to the hangar around 1000 to hook = up my new=20 digital Fuel Monitoring system.  The Bad news is it read the = first=20 pulse and froze (more on this later), so I was a bit discouraged, though = it=20 might be the EFI pulse might be dirty compared to the laboratory pulse I = had=20 been using to test the unit.  Figured I would have to haul my = oscilloscope=20 out to the hangar tomorrow to see what the EFI  pulse train = actually looked=20 like.
 
But, while scratching my head, my two = new next-door=20 hangar neighbors showed up to fly their Kobe Ultralight.  These are = both=20 older airline pilots (one retired) who decided to fly utralights - = without any=20 lessons of course.  But, nice guys just the same.  The first = flight=20 made about two weeks ago ended up with one of the landing struts bent = from=20 dropping it in a bit high. 
 
Today they were back for another = try.  Number=20 one takes off and it sounds like to me that he is not making anywhere = near full=20 power.  He flys around the pattern a couple of times making passes = at the=20 runway and finally sets it down with about a 2 foot drop - not too = pretty but=20 respectable.  He then is trying to talk his buddy into taking it up = - as=20 they are discussing how it handles, I over hear him make a comment that = at full=20 throttle the power fades and you have to pull it back to around 4500 rpm = ( the=20 max he has reached) to get the power back.
 
Well, I know nothing about rotax = engines but that=20 sounded like fuel starvation at higher power settings.  I asked = what type=20 fuel pump they had and it turns out it is a diaphragm type driven = by=20 pulsation's from the engine via a tube.  Sure enough as I looked it = over, I=20 found that the tube from the engine to the pump that provided the = suction pulses=20 to work the diaphragm was crimped almost shut near the pump where it was = difficult to see.  Clearly not a good condition, I point this out = to them=20 and they rapidly put on a new tube.
 
Fired it up and got almost 6000 rpm on = the=20 ground.  Took off and look like he was going straight up - a marked = difference in performance.  Don't know if this condition would have = resulted in an accident - but clearly not a good situation.
 
So they day turned out not so bad after = all. =20 Then I got home hooked up the EFI monitor and it wouldn't work there = either=20 !!!!!
 
Turns out I changed ONE line of code = this=20 morning before taking it out and had not bothered to check it on = the=20 laboratory pulse meter. I mean it was a very simple change = {:>). =20  It didn't work on it any better back at home than it did on the=20 aircraft.  But, it was a relief to know it was a simply code screw=20 up.  Eliminated that line of code and all is back = working.
 
So what started out to be a bad day = (relatively=20 speaking) ended up pretty nice.
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.com
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