X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 01 Feb 2010 11:40:20 -0500 Message-ID: X-Original-Return-Path: Received: from web111405.mail.gq1.yahoo.com ([67.195.15.156] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with SMTP id 4106359 for lml@lancaironline.net; Mon, 01 Feb 2010 00:11:32 -0500 Received-SPF: none receiver=logan.com; client-ip=67.195.15.156; envelope-from=randylsnarr@yahoo.com Received: (qmail 87855 invoked by uid 60001); 1 Feb 2010 05:10:57 -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=Y/TGD4eXm9AocgfyDG2O+oQKXJOIgTQk2WoUqePd+nInmAwQyDkjONUyB3OYsAL+fhpjm06J733MrYnYCuFrQNMv3MZObk8P8jyiNzBfjg0FbLFQehGV30gfanmzCwhD6C50BWfRleTxhOPwNswNFZWqTqotNkhu981eSbvYKU0=; X-Original-Message-ID: <876032.87658.qm@web111405.mail.gq1.yahoo.com> X-YMail-OSG: cUdIXlsVM1kicE_PR..1_ZDxFlNC4ACMla8H97ESdiXB2ioqCz.rdKmjS7Gv.qpFcwPgqspxcBfEmIr4V0TGjCPljZC2a.u7TYE2wqNl1nNGRIJsq2M5Bt98YWBa6Mk50lrnRHmtHtEcdtLZE0uO.zdz0vo6__Z5b4nNRnLqrpHZV_fc7QP6EghVWCn5.7intyaYGORC3_kzl.5ypAybzVFcz9PIyxcFgDEw_i2zzOrSXZuTRzxXcq9J0wIUgxD3_fam48NAGucTiyAxY9jvQumU6mlgIZeeL7_OX1DH51C64zHKIhT2UI.YkgxUjbmONeRJUBiXDQsTzTEhRzTV09E8Mp0Alx1mN_Qeb1OLW92MFDgZtzxsUPjt6QhDuiyl.g-- Received: from [76.8.220.18] by web111405.mail.gq1.yahoo.com via HTTP; Sun, 31 Jan 2010 21:10:57 PST X-Mailer: YahooMailClassic/9.1.10 YahooMailWebService/0.8.100.260964 X-Original-Date: Sun, 31 Jan 2010 21:10:57 -0800 (PST) From: randy snarr Subject: Re: [LML] Re: Engine out gear down Issue/The procedure! This was a wake up call for me.. X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1506293269-1265001057=:87658" --0-1506293269-1265001057=:87658 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable There has been some very good points made. I would like to hear from an instructor in the HPAT program on their though= ts on the matter. I also would like to hear form someone that has successfully landed an LNC2= with a truly dead engine.. Tragically, there are several who have attempted what we are discussing and= could add to this discussion who are no longer with us...=20 Randy Snarr N694RS --- On Sun, 1/31/10, Gary Casey wrote: From: Gary Casey Subject: [LML] Re: Engine out gear down Issue/The procedure! This was a wak= e up call for me.. To: lml@lancaironline.net Date: Sunday, January 31, 2010, 7:57 AM I ran through some numbers regarding Michael's comments below. =A0Starting = with the sailplane comment, he says that slowing from 135kts to 65 in a zoo= m can result in a gain of 800 feet. =A0If all the energy were converted to = altitude(no drag) the gain would be 1,276 ft, so a gain of 800 ft seems rea= sonable for a very low-drag airframe - 2/3 of the energy can be converted t= o altitude. =A0In the case mentioned of 120 kts to 75 kts the number comes = out to a gain of 765 ft. =A0How much of that is eaten up by drag? =A0Certai= nly compared to the sailplane, a lot. =A0Would the altitude gain be half? = =A0I doubt it. =A01/4? =A0Maybe, so as a guess you could count on perhaps a= 200 ft altitude gain. =A0How much do you need to flare? =A0Depends on the = descent rate.=0A =A0I 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 me= ntioned above. =A0It 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 sho= uld leave more than enough energy to flare. =A0How much more? =A0I'll bet n= ot a lot, but still more. =A0I don't have an answer to the question, but th= is is how the numbers work out. =A0I have done a full-flap no-power descent= with my ES (gear down, of course :-) at 105 kts and the descent rate was o= ver 2,000 ft/min with a frighteningly high negative deck angle. =A0Flaring = from that condition would be interesting, to say the least. =A0My conclusio= n is that Randy's warning is well founded. I would, perhaps, disagree with the admonition that retracting flaps when o= n=0A final will result in a guaranteed disaster. =A0Certainly 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 degrees = of flaps is 90% drag. =A0So, if one were to think he was high for the landi= ng, added full flaps and then discovered he was now low, I see no problem w= ith then retracting the flaps to 10 or 20 degrees. =A0Assuming the speed we= re high (120?) the flaps could even be retracted all the way without proble= m except for the pitch change required. =A0And then dropping the flaps duri= ng the flare is a good way to arrest the descent. =A0I'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 stay= s in Holiday Inn Express) except for a modest understanding of the engineer= ing principles=0A involved. Gary From: Michael Newman Subject: [LML] Re: Engine out gear down Issue/The procedure! This was a wak= e 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.=A0This discussion reminds me of one in the sailplane community = talking about deploying full spoilers and being able to flare properly. It = was thoroughly debunked there as it should be here.=A0The issue is carrying= enough energy in the form of airspeed to arrest the rate of descent withou= t going below the stall speed.=A0There is no=0A question in my mind that th= e IV-P with gear down, flaps down, engine stopped and spoilers fully extend= ed can carry enough 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 a= nd flaps down. 95 knots is plenty of airspeed to arrest the descent in this= configuration with the engine as pulled back as I can get it.=A0 I doubt a= truly dead engine will add as much more drag as the full spoilers.=A0Glidi= ng at 120 knots=0A with a stall speed is in the range of 75 knots is a diff= erential 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 a= ltitude you gain for converting this much horizontal speed to vertical spee= d. In sailplanes we expect about an=A0 800 foot altitude gain in a pull up = from 135 knots to 60 knots. Possibly a =A0surprise to people here is that a= Lancair will not be much different. It is energy conversion not drag that = matters.=0A=0A=0A=0A =0A=0A =0A=0A=0A --0-1506293269-1265001057=:87658 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
There has been some very good points made.
I would like to hear from an instructor in the HPAT program on their t= houghts on the matter.

I also would like to hear form someone that h= as successfully landed an LNC2 with a truly dead engine..
Tragically, th= ere are several who have attempted what we are discussing and could add to = this discussion who are no longer with us...

Randy Snarr
N694RS<= br>
--- On Sun, 1/31/10, Gary Casey <casey.gary@yahoo.com> wrote:

From: Gary Casey <casey.ga= ry@yahoo.com>
Subject: [LML] Re: Engine out gear down Is= sue/The procedure! This was a wake up call for me..
To: lml@lancaironlin= e.net
Date: Sunday, January 31, 2010, 7:57 AM

I ran through some numbers regarding Mich= ael's comments below.  Starting with the sailplane comment, he says th= at slowing from 135kts to 65 in a zoom can result in a gain of 800 feet. &n= bsp;If all the energy were 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 airfram= e - 2/3 of the energy can be converted to altitude.  In the case menti= oned of 120 kts to 75 kts the number comes out to a gain of 765 ft.  H= ow much of that is eaten up by drag?  Certainly compared to the sailpl= ane, a lot.  Would the altitude gain be half?  I doubt it.  = 1/4?  Maybe, so as a guess you could count on perhaps a 200 ft altitud= e gain.  How much do you need to flare?  Depends on the descent rate.=0A  I calculated it based on 2,000 ft/min - arresting that is e= quivalent to an altitude gain of 34.5 ft, much lower than the 200 ft mentio= ned above.  It would be good if someone measured the actual no-power d= escent rate with gear and flaps down.

In summary, = the math suggests that a no-power approach speed of 120 kts should leave mo= re than enough energy to flare.  How much more?  I'll bet not a l= ot, 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 kts and the descent rate was o= ver 2,000 ft/min with a frighteningly high negative deck angle.  Flari= ng from that condition would be interesting, to say the least.  My con= clusion is that Randy's warning is well founded.

I= would, perhaps, disagree with the admonition that retracting flaps when on= =0A 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 degree= s 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 prob= lem 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 withou= t problem 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 li= ttle reluctant to post this last paragraph as I have no credentials (no mil= itary fighter jet experience, no instructor rating, no multi-engine jet tim= e, and no stays in Holiday Inn Express) except for a modest understanding o= f the engineering principles=0A involved.

Gary

From: Michael Newman <mnewman@dragonnorth.com>
Subject: [LML] R= e: Engine out gear down Issue/The procedure! This was a wake 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 community talkin= g about deploying full spoilers and being able to flare properly. It was th= oroughly debunked there as it should be here.

 

The issue is carrying enough energy in the form = of airspeed to arrest the rate of descent without going below the stall spe= ed.

 

= There is no=0A 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 have= landed my IV-P with full spoilers, gear and flaps down. 95 knots is plenty= 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.

 = ;

Gliding at 120 knots=0A with a stall spee= d 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 vertical speed. In sailplanes we expect about an&= nbsp; 800 foot altitude gain in a pull up from 135 knots to 60 knots. Possi= bly a  surprise to people here is that a Lancair will not be much diff= erent. It is energy conversion not drag that matters.

=0A=0A=0A=0A

=0A=0A =

=0A=0A --0-1506293269-1265001057=:87658--