X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 15 Dec 2009 16:33:59 -0500 Message-ID: X-Original-Return-Path: Received: from smtp.webpartner.dk ([195.184.96.12] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTP id 4022464 for lml@lancaironline.net; Tue, 15 Dec 2009 16:05:23 -0500 Received-SPF: none receiver=logan.com; client-ip=195.184.96.12; envelope-from=ulla@essbredbaand.dk Received: from familie (2208ds1-sdb.0.fullrate.dk [90.185.216.185]) by asmtp.webpartner.dk (Postfix) with ESMTP id 952DF935E4B for ; Tue, 15 Dec 2009 22:04:43 +0100 (CET) From: "Ulla" X-Original-To: "Lancair Mailing List" Subject: SV: [LML] feathering props X-Original-Date: Tue, 15 Dec 2009 22:04:55 +0100 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004A_01CA7DD2.A2202420" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 In-Reply-To: Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_004A_01CA7DD2.A2202420 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Colyn I am not sure how your prop works, but I have been flying a Piper Seneca PA34 for some years. If you lose oilpressure the prop goes to fine pich as it is spring loaded - why, in case of a goaround you can still use the engine/prop safely. It is not vise to make a goaround with a feather prop. If you have an engine failer in the air and want to shut down the engine you must feather the prop before 800 rpm. Below 800 rpm there is a prop lock and you can not feather any more giving you a lot of drag. Leon Lancair ES -----Oprindelig meddelelse----- Fra: Lancair Mailing List [mailto:lml@lancaironline.net]På vegne af Colyn Case at earthlink Sendt: 15. december 2009 04:52 Til: lml@lancaironline.net Emne: [LML] feathering props I have a full feathering prop on my IVP. ....but there are some holes in my understanding I wonder if someone has a definitive understanding of. I believe the following are true: - on this prop oil pressure pushes it to fine pitch and springs push to coarse pitch - if you lose oil pressure, it will go to feather - if you pull the prop control all the way out it will go to feather - if you do an air start from feather and you have a strong battery and starter, you can get it out of feather in about 25 seconds. - it has prop locks which prevent it from going to coarse on a normal shut down. Here's what I dont' understand: - EXACTLY how do the prop locks work? It seems that if you get rpm below 1200 but haven't lost oil pressure, somehow the prop locks will keep it from going to full feather when you finally lose all pressure. - If the engine were at 1100 rpm when you lost power, what would happen? I assume the prop locks keep it from feathering. - If the prop is windmilling, you have oil pressure. If you slowly pull the prop back til it's below 1200rpm and then continue all the way back, how is this different than a normal shut down, as far as the prop is concerned? In other words, are there scenarios where the prop locks can bite you in the air and what are they? Colyn ------=_NextPart_000_004A_01CA7DD2.A2202420 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Colyn

I am=20 not sure how your prop works, but I have been flying a Piper Seneca PA34 = for=20 some years. If you lose oilpressure the prop goes to fine pich as it is = spring=20 loaded - why, in case of a goaround you can still use the = engine/prop=20 safely. It is not vise to make a goaround with a feather=20 prop.

If you=20 have an engine failer in the air and want to shut down the=20 engine you must feather the prop before 800 rpm. Below = 800 rpm=20 there is a prop lock and you can not feather any more giving you a lot = of=20 drag.

Leon

Lancair ES

-----Oprindelig meddelelse-----
Fra: Lancair = Mailing List=20 [mailto:lml@lancaironline.net]P=E5 vegne af Colyn Case at=20 earthlink
Sendt: 15. december 2009 04:52
Til:=20 lml@lancaironline.net
Emne: [LML] feathering=20 props

I have a full feathering prop on my=20 IVP.

....but there are some holes in my = understanding=20 I wonder if someone has a definitive understanding of.

I believe the following are = true:

- on this prop oil pressure pushes it = to fine=20 pitch and springs push to coarse pitch

- if you lose oil pressure, it will = go to=20 feather

- if you pull the prop control all = the way out it=20 will go to feather

- if you do an air start from feather = and you=20 have a strong battery and starter, you can get it out of feather in = about 25=20 seconds.

- it has prop locks which prevent it = from going=20 to coarse on a normal shut down.

Here's what I dont' = understand:

- EXACTLY how do the prop locks = work? It=20 seems that if you get rpm below 1200 but haven't lost oil pressure, = somehow=20 the prop locks will keep it from going to full feather when you = finally lose=20 all pressure.

- If the engine were at 1100 rpm when = you lost=20 power, what would happen? I assume the prop locks keep it = from=20 feathering.

- If the prop is windmilling, you = have oil=20 pressure. If you slowly pull the prop back til it's below = 1200rpm and=20 then continue all the way back, how is this different than a normal = shut down,=20 as far as the prop is concerned?

In other words, are there scenarios = where the=20 prop locks can bite you in the air and what are they?

Colyn

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