X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 18 Jun 2011 09:15:13 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-dupuy.atl.sa.earthlink.net ([209.86.89.62] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTP id 5024021 for lml@lancaironline.net; Fri, 17 Jun 2011 18:18:56 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.62; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=dH6JoiQBdFBErmR95yUwXNShfYvBE2JP8IrhTpi5edFD5ooQ3WYDXuXrhdQY6C0e; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [66.201.52.88] (helo=[10.71.1.115]) by elasmtp-dupuy.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1QXhMs-0006Am-Ai for lml@lancaironline.net; Fri, 17 Jun 2011 18:18:22 -0400 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: multipart/alternative; boundary=Apple-Mail-657--670581000 Subject: Re: [LML] Re: Stall Speeds, Wing Cuffs, Vortex Generators for Lancair 4p X-Original-Date: Fri, 17 Jun 2011 15:18:20 -0700 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <001AB8E9-0009-4691-9052-3BDF5CF2D41F@earthlink.net> X-Mailer: Apple Mail (2.1082) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940b2f32c4d0387fc7731934d6b40be61af350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 66.201.52.88 --Apple-Mail-657--670581000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Ronald, be careful looking at someone else's charts. On my airplane Len tested at 3 different weights and CG's. The differences are HUGE. Also, typically stall buffet was 1 or 2 knots above stall or totally = non-existent. Charlie Kohler has some strong opinions about stall strips. A big fat = one will give you a more definite buffet. I don't know how many knots advance warning you get though. I bet = Charlie knows. My point is, in an inadvertent stall (e.g. a turn) , by the time you are = 1-2 knots away you airspeed is probably changing very quickly and you = will HAVE stalled by the time you recognize the buffet. I like the AOA system because you get more advance warning. On Jun 17, 2011, at 9:45 AM, RONALD STEVENS wrote: > Hi Bob >=20 > I agree but you need to know when stall speed comes close, so using = the pre stall signs would be good enough for me. In other words, if I = would feel a buffet at 75 then I consider 75 as my stall speed, then add = 20 for Final and you should be good to land with a safe enough margin = (wind shear, distractions etc) >=20 > I am the last one to try to explore, but the knowledge where it is is = something you need to know. You cannot expect to have the same stall = speed as your fellow 4p owner, because he might have built the plane the = right way LOL (just kidding) >=20 > Most stall speeds I have seen are between 72-78 kts (landing = configuration) but I even found online a plane that claims 61/67 kts = (and I am pretty sure this was a typo, but just imagine you would take = this as 'your' number, oops ;) >=20 > So exploring is dangerous, totally agree on that, that is why I would = not go further then the buffet and consider this 'your' number :) >=20 > =3D=3D Ronald >=20 > From: Bob Rickard > Reply-To: Lancair Mailing List > Date: Thu, 16 Jun 2011 15:24:01 -0400 > To: > Subject: [LML] Re: Stall Speeds, Wing Cuffs, Vortex Generators for = Lancair 4p >=20 > One of the main reasons all of us IV-P owners have a hell of a time = getting insurance for our airplanes is because too many guys "explored" = the stall characteristics of their airplane (and for many it was their = last flight). I fly another airplane that can fly comfortably at 60 = degrees AOA, and have a good bit of time as an operational test pilot, = but I will never stall my IV-P intentionally. Or even get close. Like = Colyn and John, I'm 120 on downwind, 110 at the base turn and 100 on = final until the runway is assured. Unless we fly the pattern at 8000 = feet AGL, a stall will probably be fatal for any of us. Please don't be = the next one to prove this point ! >=20 > Bob Rickard >=20 >=20 >=20 > On Jun 16, 2011, at 8:16 AM, Colyn Case = wrote: >=20 >> My speeds are similar. I would caution that this is test pilot = stuff. =20 >> I indexed my wings also. The result was that the plane became = ambivalent as to which direction it was going to roll off suddenly in = the stall. >> We also found that moving the stall strip which a bit down from the = leading edge would reduce the wall but increase stall speed 10 knots. >>=20 >> On Jun 16, 2011, at 7:24 AM, John Hafen wrote: >>=20 >>> Ronald: >>>=20 >>> My IVP stalls clean at 76 kts clean, and 65 kts in landing = configuration. But I never get that slow. Or even close. I fly = downwind at 130, a very rounded base / transition to final at 120, and = approach at 110 on final, slowing down to 100 over the fence. >>>=20 >>> One of the things my bird did when I was doing the initial testing = was a 90 degree snap roll to the right when I stalled it (And I mean = Snap!). =46rom there, it's pretty easy to get into a spin. >>>=20 >>> I fly a 1500 foot pattern for a little extra safety, knowing that = any stall even at that altitude would be un-recoverable. >>>=20 >>> Eventually, I had the wings "indexed," and ended up lowering the = trailing edge of the right wing slightly perhaps 3/16th of an inch. It = now stalls straight ahead and I think my stall speeds were lowered = slightly because of that exercise. But it is still a squirrely stall = that seems very unnatural compared to other planes I've flown. it does = this weird yaw thing, maybe because of the small tail. >>>=20 >>> A 4P is not your father's Olsmobile, or a Cessna. I's not a good = plane to go slow and low for sight seeing. And 4P's are all different. = Not all of them are square. You're smart to test it out before you buy = to find a good one. >>>=20 >>> All of this said, I LOVE my plane. I love that it is fast. You = just have to know the machine to stay safe. >>>=20 >>> John Hafen >>> IVP 413AJ 300 hours >>>=20 >>> On Jun 15, 2011, at 5:24 PM, RONALD STEVENS wrote: >>>=20 >>> I know this is a sensitive subject but I just got a flight test = review back from a plane that I am thinking to buy and was a bit = surprised about the stall speeds that were in there. >>>=20 >>> What kind of stall speed (clean/50%/Dirty) do you have in your 4p? = And were you ever thinking of having it improved by Vortex Generators or = Wing cuff? >>>=20 >>> Thanks -- Ronald >>>=20 >>=20 --Apple-Mail-657--670581000 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii
Hi = Bob

I agree but you need to know when stall = speed comes close, so using the pre stall signs would be good enough for = me. In other words, if I would feel a buffet at 75 then I consider 75 as = my stall speed, then add 20 for Final and you should be good to land = with a safe enough margin (wind shear, distractions = etc)

I am the last one to try to explore, but = the knowledge where it is is something you need to know. You cannot = expect to have the same stall speed as your fellow 4p owner, because he = might have built the plane the right way LOL (just = kidding)

Most stall speeds I have seen are = between 72-78 kts (landing configuration) but I even found online a = plane that claims 61/67 kts (and I am pretty sure this was a typo, but = just imagine you would take this as 'your' number, oops = ;)

So exploring is dangerous, totally agree on = that, that is why I would not go further then the buffet and consider = this 'your' number :)

=3D=3D = Ronald

From: Bob Rickard <r.rickard@rcginc-us.com>Reply-To: Lancair Mailing List = <lml@lancaironline.net>
Date: Thu, 16 Jun 2011 15:24:01 = -0400
To: <lml@lancaironline.net>
Subject: [LML] Re: Stall Speeds, = Wing Cuffs, Vortex Generators for Lancair = 4p

One of the = main reasons all of us IV-P owners have a hell of a time getting = insurance for our airplanes is because too many guys "explored" the = stall characteristics of their airplane (and for many it was their last = flight).   I fly another airplane that can fly comfortably at 60 = degrees AOA, and have a good bit of time as an operational test pilot, = but I will never stall my IV-P intentionally.  Or even get close. =  Like Colyn and John, I'm 120 on downwind, 110 at the base turn and = 100 on final until the runway is assured.   Unless we fly the = pattern at 8000 feet AGL, a stall will probably be fatal for any of us. =  Please don't be the next one to prove this point = !

Bob Rickard



On Jun = 16, 2011, at 8:16 AM, Colyn Case <colyncase@earthlink.net> = wrote:

My speeds = are similar.   I would caution that this is test pilot stuff. =   
I indexed my wings also.  The result was that the = plane became ambivalent as to which direction it was going to roll off = suddenly in the stall.
We also found that moving the stall = strip which a bit down from the leading edge would reduce the wall but = increase stall speed 10 knots.

On Jun 16, 2011, = at 7:24 AM, John Hafen wrote:

Ronald:

My = IVP stalls clean at 76 kts clean, and 65 kts in landing configuration. =  But I never get that slow.  Or even close.  I fly = downwind at 130, a very rounded base / transition to final at 120, and = approach at 110 on final, slowing down to 100 over the = fence.

One of the things my bird did when I was doing = the initial testing was a 90 degree snap roll to the right when I = stalled it (And I mean Snap!).  =46rom there, it's pretty easy to = get into a spin.

I fly a 1500 foot pattern for = a little extra safety, knowing that any stall even at that altitude = would be un-recoverable.

Eventually, I had the = wings "indexed," and ended up lowering the trailing edge of the right = wing slightly perhaps 3/16th of an inch.  It now stalls straight = ahead and I think my stall speeds were lowered slightly because of that = exercise.  But it is still a squirrely stall that seems very = unnatural compared to other planes I've flown.  it does this weird = yaw thing, maybe because of the small tail.

A = 4P is not your father's Olsmobile, or a Cessna.  I's not a good = plane to go slow and low for sight seeing.   And 4P's are all = different.  Not all of them are square.  You're smart to test = it out before you buy to find a good one.

All = of this said, I LOVE my plane.  I love that it is fast.  You = just have to know the machine to stay safe.

John = Hafen
IVP 413AJ 300 hours

On Jun 15, = 2011, at 5:24 PM, RONALD STEVENS wrote: