X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 16 Dec 2009 10:02:31 -0500 Message-ID: X-Original-Return-Path: Received: from web33908.mail.mud.yahoo.com ([209.191.69.186] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with SMTP id 4023085 for lml@lancaironline.net; Tue, 15 Dec 2009 23:31:12 -0500 Received-SPF: none receiver=logan.com; client-ip=209.191.69.186; envelope-from=wfhannahan@yahoo.com Received: (qmail 84155 invoked by uid 60001); 16 Dec 2009 04:30:38 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=yJPJKZ4z+Y5WvY6Tx5icg1jo1FivtAs7LG+8OHj+sprONoKHv0FJxQFVO3RcORfE0RpxkXx8KPKc23FbG655Aqp+cCo+CDiXTxR2emZKtN8P8fAQYJ6KXnKA7UfEFJ6qDAiz0fda4JI90EZLiQ33jWQzgOd0OgAKUjl0pCSxIaY=; X-Original-Message-ID: <760748.78595.qm@web33908.mail.mud.yahoo.com> X-YMail-OSG: NIoSFbkVM1lDobvsd7mjnNAY2G3rybXJOdfmmiTM283yPwGNTrjwdiSfr3RGe5JKg_unWeXI_Qa.Ld.dYqTYs9iInK4uXGo6ZJGL8onll8pQP1Cf6MTSfqsec7Yjid45IH0WYXH2_YaOaUGvIbONTYuhG4VdnIWZxaW1HvAKpdTbtc2KwkgCQylCM.heylsTSpGUq_u6hu4zkCOtxNyfIsiidmlXxAtOTnX4vhVR3YoG2tmkHvnLCsJgzq_alm_1oHBTjkijsaxp2aIDqMJ0S30kht.3QlSsl6bxe4VBVhH.A3RTy1RIGzNtvUwuEeHuJFH0LZ4yYHsCF9xsr.7RK3Dpg7Z_7mDxBR0lswUld4jOyQ-- Received: from [71.208.24.120] by web33908.mail.mud.yahoo.com via HTTP; Tue, 15 Dec 2009 20:30:38 PST X-Mailer: YahooMailClassic/9.0.19 YahooMailWebService/0.8.100.260964 X-Original-Date: Tue, 15 Dec 2009 20:30:38 -0800 (PST) From: Bill Hannahan Subject: Legacy Crash Watsonville? X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-610814137-1260937838=:78595" --0-610814137-1260937838=:78595 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable =0A=0A=0A=0A=0A=0A=C2=A0=0A=0ASome thoughts on props. While building my 360= I considered=0Agoing with a feathering prop. At the time I could not come = up with a strong=0Aadvantage for it, and went with the flow.=0A=0A=C2=A0=0A= =0A1=E2=80=A6 My question was and is, what are the most common failure=0Amo= des with a featherable prop and governor combination, and what are the=0Apr= obabilities of each of those failure modes?=0A=0A=C2=A0=0A=0AMy uneducated = guess is that the most common failure would be=0Aa sheared driveshaft leadi= ng to loss of oil pressure to the prop and feathering=0Aof the prop, requir= ing a dead stick landing with a perfectly good engine.=0A=0A=C2=A0=0A=0AIf = so, the next question is, does the advantage of improved=0Aglide ratio more= than offset the disadvantage of a slight increased frequency=0Aof power [t= hrust] failure? If not so, why don=E2=80=99t all single engine planes have= =0Afeathering props?=0A=0A=C2=A0=0A=0A=C2=A0=0A=0A2=E2=80=A6During flight t= esting I discovered that with the prop on=0Athe flat pitch stops I could ba= rely keep the plane in the air at 2700 rpm. In a=0Areal emergency the engin= e temps would rapidly move past red line.=0A=0A=C2=A0=0A=0ATo test this at = altitude, set the prop for max rpm. Then=0Aslow down gradually until you se= e the rpm begin to decrease, indicating the=0Aprop is on the stop. Can you = maintain that speed without overheating?=0A=0A=C2=A0=0A=0AI adjusted the pi= tch stop [ screw on centerline, front of=0Adome] to maintain 120 mph at 265= 0 rpm. I do not see 2700 rpm until deep into=0Athe takeoff roll, but it sti= ll accelerates like a dragster, so I do not see it=0Aas a big sacrifice. I = would not detect a governor failure till late in the=0Atakeoff, but I can s= top on a long runway or fly it safely around the patch on a=0Ashort one.=0A= =0A=C2=A0=0A=0A3=E2=80=A6 My normal cross country power setting is 1,800/18= inches=0Awhich gives 200 mph tas on 6 gph above 10,000=E2=80=99. This has = the prop very close to=0Athe high pitch stop. Running into the stop would b= e a bit like trying to turn=0Ayour power steering past full lock. I check t= his occasionally by turning the=0Arpm down briefly and looking for a drop. = If no drop you must increase the rpm=0Asetting until you get an increase. I= try to keep it at least 20 rpm above the=0Astop in cruise.=0A=0A=C2=A0=0A= =0AOn descent I would like to hold the rpm down and keep the mp=0Aup to kee= p the engine warm without making much power, but I must increase the=0Arpm = to keep it off the stop, increasing fuel flow and power when I don=E2=80=99= t want=0Ait. The feathering prop would solve this problem.=0A=0A=C2=A0=0A= =0ARegards, Bill Hannahan =20 wfhannahan@yahoo.com --- On Tue, 12/15/09, farnsworth wrote: From: farnsworth Subject: [LML] Re: Legacy Crash Watsonville? To: lml@lancaironline.net Date: Tuesday, December 15, 2009, 2:33 PM It is my understanding that the crash occurred close to the airport. I thin= k I read it was about 1 mile. If that is true I think that the glide range difference between a standard constant speed prop and a feathering prop would have made the difference between making the airport and not. I believe it was reported that the pilot said he was at 7,000' when the problem occurred. The fact that he made it to within 1 mile of a safe landing with a standard prop (I don't know if he pulled his prop control back of not. I think the engine was not turning at the time of ground contact.)is evidence that the higher glide ratio of the feathering prop would have extended his range enough to land at the airport. With loss of oil pressure the feathering prop I have in my plane feathers automatically. It does not require me to pull the prop control back. Three years ago, at the Reno Air Races, Lee Behel was flying his Legacy in the valley to the West of Stead when he had an engine failure. It was touch and go on whether he would have an off airport landing or not. The difference was the feathering prop on his plane. If he had had a standard prop he would not have made the airport for an uneventful landing.=C2=A0=20 I just think a feathering prop is cheap insurance. > > Lynn Farnsworth > Super Legacy #235 > TSIO-550 Powered > Race #44 > Mmo .6 Mach > Feathering Prop -- -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html =0A=0A=0A --0-610814137-1260937838=:78595 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
= =0A=0A

 

=0A=0A

Some thoughts on props. While= building my 360 I considered=0Agoing with a feathering prop. At the time I= could not come up with a strong=0Aadvantage for it, and went with the flow= .

=0A=0A

 

=0A=0A

1=E2=80=A6 My question was and is, what are the most common failur= e=0Amodes with a featherable prop and governor combination, and what are th= e=0Aprobabilities of each of those failure modes?

=0A=0A

 

=0A=0A

My uneducated gues= s is that the most common failure would be=0Aa sheared driveshaft leading t= o loss of oil pressure to the prop and feathering=0Aof the prop, requiring = a dead stick landing with a perfectly good engine.

=0A=0A

 

=0A=0A

If so, the next q= uestion is, does the advantage of improved=0Aglide ratio more than offset t= he disadvantage of a slight increased frequency=0Aof power [thrust] failure= ? If not so, why don=E2=80=99t all single engine planes have=0Afeathering p= rops?

=0A=0A

 

=0A=0A

 

=0A=0A

2=E2=80=A6= During flight testing I discovered that with the prop on=0Athe flat pitch s= tops I could barely keep the plane in the air at 2700 rpm. In a=0Areal emer= gency the engine temps would rapidly move past red line.

=0A=0A

 

=0A=0A

To test th= is at altitude, set the prop for max rpm. Then=0Aslow down gradually until = you see the rpm begin to decrease, indicating the=0Aprop is on the stop. Ca= n you maintain that speed without overheating?

=0A=0A

 

=0A=0A

I adjusted the pitch = stop [ screw on centerline, front of=0Adome] to maintain 120 mph at 2650 rp= m. I do not see 2700 rpm until deep into=0Athe takeoff roll, but it still a= ccelerates like a dragster, so I do not see it=0Aas a big sacrifice. I woul= d not detect a governor failure till late in the=0Atakeoff, but I can stop = on a long runway or fly it safely around the patch on a=0Ashort one.

=0A= =0A

 

=0A=0A

3=E2=80=A6 My normal cross country power setting is 1,800/18 inches=0Awhic= h gives 200 mph tas on 6 gph above 10,000=E2=80=99. This has the prop very = close to=0Athe high pitch stop. Running into the stop would be a bit like t= rying to turn=0Ayour power steering past full lock. I check this occasional= ly by turning the=0Arpm down briefly and looking for a drop. If no drop you= must increase the rpm=0Asetting until you get an increase. I try to keep i= t at least 20 rpm above the=0Astop in cruise.

=0A=0A

 

=0A=0A

On descent I would lik= e to hold the rpm down and keep the mp=0Aup to keep the engine warm without= making much power, but I must increase the=0Arpm to keep it off the stop, = increasing fuel flow and power when I don=E2=80=99t want=0Ait. The featheri= ng prop would solve this problem.

=0A=0A

&nbs= p;

=0A=0A
Regards,
Bill Hannahan

<= a rel=3D"nofollow" target=3D"_blank" href=3D"mailto:wfhannahan@yahoo.com">w= fhannahan@yahoo.com


--- On Tue, 12/15/09, farnsworth <farnsworth@charter.net> wrote:
=
From: farnsworth <farnsworth@charter.net>
Subject: [LML] Re: L= egacy Crash Watsonville?
To: lml@lancaironline.net
Date: Tuesday, Dec= ember 15, 2009, 2:33 PM



It is my un= derstanding that the crash occurred close to the airport. I think
I read= it was about 1 mile. If that is true I think that the glide range
diffe= rence between a standard constant speed prop and a feathering prop
would= have made the difference between making the airport and not.

I beli= eve it was reported that the pilot said he was at 7,000' when the
proble= m occurred. The fact that he made it to within 1 mile of a safe
landing with a standard prop= (I don't know if he pulled his prop control
back of not. I think the en= gine was not turning at the time of ground
contact.)is evidence that the= higher glide ratio of the feathering prop
would have extended his range= enough to land at the airport. With loss of
oil pressure the feathering= prop I have in my plane feathers automatically.
It does not require me = to pull the prop control back.

Three years ago, at the Reno Air Race= s, Lee Behel was flying his Legacy in
the valley to the West of Stead wh= en he had an engine failure. It was touch
and go on whether he would hav= e an off airport landing or not. The
difference was the feathering prop = on his plane. If he had had a standard
prop he would not have made the a= irport for an uneventful landing. 

I just think a feathering p= rop is cheap insurance.

>
> Lynn Farnsworth
> Super Legacy #235
> TSIO-550 Powered
> Race #44
> Mmo .6= Mach
> Feathering Prop


--


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