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Return-Path: <13brv3@bellsouth.net> Received: from imf18aec.mail.bellsouth.net ([205.152.59.66] verified) by logan.com (CommuniGate Pro SMTP 4.1) with ESMTP id 2511952 for flyrotary@lancaironline.net; Tue, 05 Aug 2003 10:08:16 -0400 Received: from rad ([68.212.1.179]) by imf18aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030805140815.JDJS4876.imf18aec.mail.bellsouth.net@rad> for ; Tue, 5 Aug 2003 10:08:15 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: tiny tach works, and my plane is a pig Date: Tue, 5 Aug 2003 09:08:17 -0500 Message-ID: <000001c35b5b$04dd7640$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C35B31.1C09B830" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C35B31.1C09B830 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Before you go adding weight to the tail - my RV's forward CG (empty) = was 1/8" forward of Van's Limit (in addition to weighing 1170 lbs). I = called Vans to check on the C.G. limit and as long as it was the "forward" = limit there was no concern. They fretted more over my weight than the C.G.=20 =20 Thanks for the comments. I'm only .3" in front of the forward CG limit according to my spreadsheet, and it seems that this is a pretty common problem for people who put O-320 engines in their RV-3's, since the = plane was designed for a 125 hp engine. A friend with an O-320 RV-3 just = told me his empty weight is 822 lbs, and he publishes a gross weight of 1280, = though he keeps aerobatics below Van's recommended 1100 lb gross. =20 =20 I called Van's yesterday, and talked to one of the engineers that = designed the "B" wings for the RV-3. I am curious to know if they updated the = gross weight limits when they redesigned the wing. Unfortunately, he probably wasn't at liberty to answer that, and said he'll ask Van when he gets = back from Oshkosh. I'll be surprised if they raised the limits any, but = since the B wing is considered superior to the old wing, I feel OK about it, especially since everyone seems to be flying them at higher than = recommended gross weight anyway. =20 =20 I'm going to go to the airport today, and make some measurements of = these moment arms that are published in the manual. In particular, I'm = interested in seeing where the single moment arm that they give for the baggage compartment actually falls. It's a big baggage compartment, and I'm guessing it's in the middle of that area. Once I confirm those figures, = I can decide what to do. It's quite likely that I won't have to add any weight at all. Using the general purpose baggage arm that's given, I = can add 6 lb of weight as baggage, and be within the forward CG limit. = Since I'll always carry tie-downs, tools, plugs, and oil (when I get out of my test period), I'm sure it will add up to 6 pounds. I can also contain = this stuff in the far aft end of the compartment, where it probably won't = even need to weigh 6 pounds to make the CG limit. Bottom line, it seems like = it will all work out OK. =20 =20 Cheers, Rusty (when pigs fly)=20 ------=_NextPart_000_0001_01C35B31.1C09B830 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

Before you go = adding=20 weight to the tail - my RV's forward CG (empty) was 1/8" forward of = Van's Limit=20 (in addition to weighing 1170 lbs). I called Vans to check on the = C.G.=20 limit and as long as it was the "forward" limit there was no = concern. They=20 fretted more over my weight than the C.G.

Thanks for the comments. I'm only .3" in=20 front of the forward CG limit according to my spreadsheet, and = it=20 seems that this is a pretty common problem for people who put O-320 = engines in=20 their RV-3's, since the plane was designed for a 125 hp = engine. =20 A friend with an O-320 RV-3 just told me his empty weight is 822 lbs, = and he=20 publishes a gross weight of 1280, though he keeps aerobatics = below Van's=20 recommended 1100 lb = gross.

I called Van's yesterday, and talked to one = of the=20 engineers that designed the "B" wings for the RV-3. I am = curious to=20 know if they updated the gross weight limits when they redesigned the=20 wing. Unfortunately, he probably wasn't at liberty to answer = that,=20 and said he'll ask Van when he gets back from Oshkosh. I'll be=20 surprised if they raised the limits any, but since the B wing=20 is considered superior to the old wing, I feel OK about it, = especially=20 since everyone seems to be flying them at higher than recommended gross = weight=20 anyway.

I'm going to go to the airport today, and = make some=20 measurements of these moment arms that are published in the = manual. In=20 particular, I'm interested in seeing where the single moment arm that = they give=20 for the baggage compartment actually falls. It's a big baggage=20 compartment, and I'm guessing it's in the middle of that = area. Once I=20 confirm those figures, I can decide what to do. It's quite likely = that I=20 won't have to add any weight at all. Using the general purpose = baggage arm=20 that's given, I can add 6 lb of weight as baggage, and be within the = forward CG=20 limit. Since I'll always carry tie-downs, tools, = plugs, and oil=20 (when I get out of my test period), I'm sure it will add up to 6 = pounds. I=20 can also contain this stuff in the far aft end of the compartment, where = it=20 probably won't even need to weigh 6 pounds to make the CG=20 limit. Bottom line, it seems like it will all work out=20 OK.

Cheers,

Rusty (when pigs = fly)

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