X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-03.southeast.rr.com ([24.25.9.102] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2077003 for flyrotary@lancaironline.net; Thu, 31 May 2007 12:26:21 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-03.southeast.rr.com (8.13.6/8.13.6) with SMTP id l4VGPPMR015731 for ; Thu, 31 May 2007 12:25:25 -0400 (EDT) Message-ID: <001501c7a3a0$51d0ed10$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" Subject: Disable Switches Was [FlyRotary] Re: It is ALIVE!!! First Start in Houston Date: Thu, 31 May 2007 12:25:36 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01C7A37E.CA7C77B0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0012_01C7A37E.CA7C77B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =20 No, Mike, you correct, you do not NEED the injector disable switches. = However, there are several reasons why you might want to consider = installing them. Should you ever have an injector malfunction - say their wire to the = EC2 grounds on your firewall- in that case, the injector (or both = assuming both of their wires grounded) will go to full open and could = possibly flood your engine - particularly if you are operating at lower = rpms. With a disable switch you could turn that pair off and fly on the = other. Even if an single injector stops functioning properly, the engine is = affected - depending on what the injector malfunction is - the engine = will likely not operating smoothly - so simply turn off the effected = injector pair and fly home - without a sputtering or bucking engine. You see your EGT start acting up - you could determine which set of = injectors (primary or secondary) is causing the problem and from there = which particular injector of the pair (rotor 1 or rotor 2 assuming you = have a separate EGT for each rotor) may be bad or acting up. I had a malfunction one time where the cold start function was forced = on (nothing to do with the switches) - with the cold start function = engage and both pairs of injector operating the engine had way too = much fuel (even when the mixture control was turned to minimum), but = switching off one pair made it possible to get home with no problem. You can also use them to shut your engine off immediately - even with = fuel in the lines, if you turn off the disable switches, the injectors = will immediately stop injecting fuel. =20 But, you are right, they are a point of failure,however, I would not = consider them a single point - unless you have the bad luck to have both = of them go out at the same time, because so long as one is working, you = can fly on one pair of injectors with no problem. =20 Again, the choice is up to you, but they do have some benefits. Ed ------=_NextPart_000_0012_01C7A37E.CA7C77B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 

No, Mike, you correct, you do not NEED the = injector=20 disable switches.  However, there are several reasons why you might = want to=20 consider installing them.
 
Should you ever have an = injector  malfunction -=20 say their  wire to the EC2 grounds on your firewall- in that = case, the=20  injector (or both assuming both of their wires grounded) will go = to full=20 open and could possibly flood your engine - particularly if you are = operating at=20 lower rpms.  With a disable switch you could turn that pair off and = fly on=20 the other.
 
Even if an single injector stops functioning = properly, the=20 engine is affected - depending on what the injector malfunction is - the = engine=20 will likely not operating smoothly - so simply turn off the effected = injector=20 pair and fly home - without a sputtering or bucking engine.
 
You see your EGT start acting up - you could = determine=20 which set of injectors (primary or secondary) is causing the problem and = from=20 there  which particular injector of the pair (rotor 1 or rotor 2 = assuming=20 you have a separate EGT for each rotor) may be bad or acting = up.
 
I had a malfunction one time where the cold = start function=20 was forced  on (nothing to do with the switches)  - with the = cold=20 start function engage and  both pairs of = injector operating=20  the engine had way too much fuel (even when the mixture control = was turned=20 to minimum), but switching off one pair made it possible to get home = with no=20 problem.
 
You can also use them to shut your engine off = immediately=20 - even with fuel in the lines, if you turn off the disable switches, the = injectors will immediately stop injecting fuel.  =
 
But, you are right, they are a point of = failure,however, I=20 would not consider them a single point - unless you have the bad luck to = have=20 both of them go out at the same time, because so long as one is working, = you can=20 fly on one pair of injectors with no problem. 
 
Again, the choice is up to you, but they do have = some=20 benefits.
 
Ed
 
 
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