X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 31 Jan 2010 23:58:12 -0500 Message-ID: X-Original-Return-Path: Received: from imr-da04.mx.aol.com ([205.188.105.146] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4105775 for lml@lancaironline.net; Sun, 31 Jan 2010 10:37:39 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.105.146; envelope-from=VTAILJEFF@aol.com Received: from imo-ma04.mx.aol.com (imo-ma04.mx.aol.com [64.12.78.139]) by imr-da04.mx.aol.com (8.14.1/8.14.1) with ESMTP id o0VFatHM011247 for ; Sun, 31 Jan 2010 10:36:55 -0500 Received: from VTAILJEFF@aol.com by imo-ma04.mx.aol.com (mail_out_v42.9.) id q.bf8.3d62f34e (45303) for ; Sun, 31 Jan 2010 10:36:50 -0500 (EST) Received: from smtprly-mb02.mx.aol.com (smtprly-mb02.mx.aol.com [64.12.207.149]) by cia-mc04.mx.aol.com (v127.7) with ESMTP id MAILCIAMC045-5c634b65a38a2f9; Sun, 31 Jan 2010 10:36:49 -0500 Received: from webmail-stg-d15 (webmail-stg-d15.sim.aol.com [205.188.185.231]) by smtprly-mb02.mx.aol.com (v127.7) with ESMTP id MAILSMTPRLYMB021-5c634b65a38a2f9; Sun, 31 Jan 2010 10:36:42 -0500 References: X-Original-To: lml@lancaironline.net Subject: Re: [LML] Re: Engine out gear down Issue/The procedure! This was a wake up call for me.. X-Original-Date: Sun, 31 Jan 2010 10:36:42 -0500 X-AOL-IP: 166.187.221.67 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: vtailjeff@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CC70A2525350FE_DD4_1C911_webmail-stg-d15.sysops.aol.com" X-Mailer: AOL Webmail 30603-STANDARD Received: from 166.187.221.67 by webmail-stg-d15.sysops.aol.com (205.188.185.231) with HTTP (WebMailUI); Sun, 31 Jan 2010 10:36:42 -0500 X-Original-Message-Id: <8CC70A2524508B2-DD4-E1F8@webmail-stg-d15.sysops.aol.com> X-Spam-Flag:NO X-AOL-SENDER: VTAILJEFF@aol.com ----------MB_8CC70A2525350FE_DD4_1C911_webmail-stg-d15.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" Some very good comments on engine out landings in Lancairs--but the bottom= line is this is something you have to practice with a very well qualified= in type instructor. 120 knots is the number. When and where you get the= gear and flaps down depends on many other factors not described here. As= Brent is fond of saying, "the only way to get to Carnegie Hall is practic= e, practice, practice." Jeff -----Original Message----- From: Gary Casey To: lml@lancaironline.net Sent: Sun, Jan 31, 2010 8:57 am Subject: [LML] Re: Engine out gear down Issue/The procedure! This was a wa= ke up call for me.. I ran through some numbers regarding Michael's comments below. Starting= with the sailplane comment, he says that slowing from 135kts to 65 in a= zoom can result in a gain of 800 feet. If all the energy were converted= to altitude(no drag) the gain would be 1,276 ft, so a gain of 800 ft seem= s reasonable for a very low-drag airframe - 2/3 of the energy can be conve= rted to altitude. In the case mentioned of 120 kts to 75 kts the number= comes out to a gain of 765 ft. How much of that is eaten up by drag? Ce= rtainly compared to the sailplane, a lot. Would the altitude gain be half= ? I doubt it. 1/4? Maybe, so as a guess you could count on perhaps a 20= 0 ft altitude gain. How much do you need to flare? Depends on the descen= t rate. I calculated it based on 2,000 ft/min - arresting that is equival= ent to an altitude gain of 34.5 ft, much lower than the 200 ft mentioned= above. It would be good if someone measured the actual no-power descent= rate with gear and flaps down. In summary, the math suggests that a no-power approach speed of 120 kts sh= ould leave more than enough energy to flare. How much more? I'll bet not= a lot, but still more. I don't have an answer to the question, but this= is how the numbers work out. I have done a full-flap no-power descent wi= th my ES (gear down, of course :-) at 105 kts and the descent rate was ove= r 2,000 ft/min with a frighteningly high negative deck angle. Flaring fro= m that condition would be interesting, to say the least. My conclusion is= that Randy's warning is well founded. I would, perhaps, disagree with the admonition that retracting flaps when= on final will result in a guaranteed disaster. Certainly any change in= configuration at the last second creates a high work load, but at least= in my airplane, the difference in behavior between 20 degrees and 40 degr= ees of flaps is 90% drag. So, if one were to think he was high for the la= nding, added full flaps and then discovered he was now low, I see no probl= em with then retracting the flaps to 10 or 20 degrees. Assuming the speed= were high (120?) the flaps could even be retracted all the way without pr= oblem except for the pitch change required. And then dropping the flaps= during the flare is a good way to arrest the descent. I'm a little reluc= tant to post this last paragraph as I have no credentials (no military fig= hter jet experience, no instructor rating, no multi-engine jet time, and= no stays in Holiday Inn Express) except for a modest understanding of the= engineering principles involved. Gary From: Michael Newman Subject: [LML] Re: Engine out gear down Issue/The procedure! This was a wa= ke up call for me... To: lml@lancaironline.net Date: Wednesday, January 27, 2010, 4:52 PM I am a LOBO instructor. I own and fly a Lancair IV-P. I am also a sailplane instructor. =20 This discussion reminds me of one in the sailplane community talking about= deploying full spoilers and being able to flare properly. It was thorough= ly debunked there as it should be here. =20 The issue is carrying enough energy in the form of airspeed to arrest the= rate of descent without going below the stall speed. =20 There is no question in my mind that the IV-P with gear down, flaps down,= engine stopped and spoilers fully extended can carry enough energy to arr= est the rate of descent (flare). 120 knots will be more than enough. I hav= e landed my IV-P with full spoilers, gear and flaps down. 95 knots is plen= ty of airspeed to arrest the descent in this configuration with the engine= as pulled back as I can get it. I doubt a truly dead engine will add as= much more drag as the full spoilers. =20 Gliding at 120 knots with a stall speed is in the range of 75 knots is a= differential of 45 knots. This is enough to climb a few hundred feet much= less arrest the rate of descent. Work out the physics and you can see how= much altitude you gain for converting this much horizontal speed to verti= cal speed. In sailplanes we expect about an 800 foot altitude gain in a= pull up from 135 knots to 60 knots. Possibly a surprise to people here= is that a Lancair will not be much different. It is energy conversion not= drag that matters. ----------MB_8CC70A2525350FE_DD4_1C911_webmail-stg-d15.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii"
Some very good comments on engine out landings in Lancairs--but the= bottom line is this is something you have to practice with a very well qu= alified in type instructor. 120 knots is the number. When and where you ge= t the gear and flaps down depends on many other factors not described here= . As Brent is fond of saying, "the only way to get to Carnegie Hall is pra= ctice, practice, practice."
 
Jeff



-----Original Message-----
From: Gary Casey <casey.gary@yahoo.com>
To: lml@lancaironline.net
Sent: Sun, Jan 31, 2010 8:57 am
Subject: [LML] Re: Engine out gear down Issue/The procedure! This was a wa= ke up call for me..

I ran through some numbers regarding Michael's comments below.  = Starting with the sailplane comment, he says that slowing from 135kts to= 65 in a zoom can result in a gain of 800 feet.  If all the energy we= re converted to altitude(no drag) the gain would be 1,276 ft, so a gain of= 800 ft seems reasonable for a very low-drag airframe - 2/3 of the energy= can be converted to altitude.  In the case mentioned of 120 kts to= 75 kts the number comes out to a gain of 765 ft.  How much of that= is eaten up by drag?  Certainly compared to the sailplane, a lot. &n= bsp;Would the altitude gain be half?  I doubt it.  1/4?  Ma= ybe, so as a guess you could count on perhaps a 200 ft altitude gain. &nbs= p;How much do you need to flare?  Depends on the descent rate.  = I calculated it based on 2,000 ft/min - arresting that is equivalent to an= altitude gain of 34.5 ft, much lower than the 200 ft mentioned above. &nb= sp;It would be good if someone measured the actual no-power descent rate= with gear and flaps down.

In summary, the math suggests that a no-power approach speed of 120= kts should leave more than enough energy to flare.  How much more?=  I'll bet not a lot, but still more.  I don't have an answer to= the question, but this is how the numbers work out.  I have done a= full-flap no-power descent with my ES (gear down, of course :-) at 105 kt= s and the descent rate was over 2,000 ft/min with a frighteningly high neg= ative deck angle.  Flaring from that condition would be interesting,= to say the least.  My conclusion is that Randy's warning is well fou= nded.

I would, perhaps, disagree with the admonition that retracting flaps= when on final will result in a guaranteed disaster.  Certainly any= change in configuration at the last second creates a high work load, but= at least in my airplane, the difference in behavior between 20 degrees an= d 40 degrees of flaps is 90% drag.  So, if one were to think he was= high for the landing, added full flaps and then discovered he was now low= , I see no problem with then retracting the flaps to 10 or 20 degrees. &nb= sp;Assuming the speed were high (120?) the flaps could even be retracted= all the way without problem except for the pitch change required.  A= nd then dropping the flaps during the flare is a good way to arrest the de= scent.  I'm a little reluctant to post this last paragraph as I have= no credentials (no military fighter jet experience, no instructor rating,= no multi-engine jet time, and no stays in Holiday Inn Express) except for= a modest understanding of the engineering principles involved.

Gary

=
From: Michael Newman <mnewman@dragonnorth.com>
Subject: [LML] Re: Engine out gear down Issue/The procedure! This was a wa= ke up call for me...
To: lml@lancaironline.net
Date: Wednesday, January 27, 2010, 4:52 PM

I am a LOBO instructor. I own and fly a Lancair IV-P.
I am also a sailplane instructor.
 
This discussion reminds me of one in the sailplane commun= ity talking about deploying full spoilers and being able to flare properly= . It was thoroughly debunked there as it should be here.
 
The issue is carrying enough energy in the form of airspe= ed to arrest the rate of descent without going below the stall speed.
 
There is no question in my mind that the IV-P with gear= down, flaps down, engine stopped and spoilers fully extended can carry en= ough energy to arrest the rate of descent (flare). 120 knots will be more= than enough. I have landed my IV-P with full spoilers, gear and flaps dow= n. 95 knots is plenty of airspeed to arrest the descent in this configurat= ion with the engine as pulled back as I can get it.  I doubt a truly= dead engine will add as much more drag as the full spoilers.
 
Gliding at 120 knots with a stall speed is in the range= of 75 knots is a differential of 45 knots. This is enough to climb a few= hundred feet much less arrest the rate of descent. Work out the physics= and you can see how much altitude you gain for converting this much horiz= ontal speed to vertical speed. In sailplanes we expect about an  800= foot altitude gain in a pull up from 135 knots to 60 knots. Possibly a &n= bsp;surprise to people here is that a Lancair will not be much different.= It is energy conversion not drag that matters.

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