X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 28 Sep 2008 14:42:19 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m23.mx.aol.com ([64.12.137.4] verified) by logan.com (CommuniGate Pro SMTP 5.2.8) with ESMTP id 3190364 for lml@lancaironline.net; Sun, 28 Sep 2008 14:33:17 -0400 Received: from Sky2high@aol.com by imo-m23.mx.aol.com (mail_out_v39.1.) id q.c30.410ecf5e (29672) for ; Sun, 28 Sep 2008 14:33:13 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Sun, 28 Sep 2008 14:33:13 EDT Subject: Re: [LML] Re: Small tail vs. large tail X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1222626793" X-Mailer: Unknown sub 34 X-Spam-Flag:NO -------------------------------1222626793 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Jeff, I guess it does depend on what one is used to. The same could be said about the "test pilots." I don't know how your tail will operate on your airplane, but consider these observations on mine: 1. In trimmed cruise, pitch change is very sensitive to wee elevator movements requiring little force. 2. In trimmed cruise, slowly rolling into a 15 degree banked turn requires little force. Quickly rolling into a steep turn (45 degrees or greater) requires a good application of side force on the stick to get to the bank angle and thereafter no side force is required as the ailerons are maintained in neutral. 3. In order to hold altitude in the steep turn without re-trimming requires adding heavy back pressure on the stick. Note: For me, leaving the cruise trim in means I know what will happen when I return to level flight. 4. During that steep turn, the forces are reversed. The ailerons are very light and the bank angle can be easily altered with slight side pressure while the elevator is held with some muscle. Altering the bank angle changes the back pressure needed to maintain altitude. 5. The forces are a bit different for left and right turns. One might conclude that stick forces are not well balanced for pitch and roll. Kinda makes you pay attention. Pitch changes change speed and speed changes change pitch - and it happens quickly. Recently, I was giving a future Lancair pilot some right seat time and I was concerned about a characteristic I noticed in practicing slow speed, small bank angle turns - the nose kept rising! If there is any sensitivity issue, it is during slow flight. The controls are very light and it is easy to quickly creep into a bad AOA, perhaps by thinking that using minor back pressure will keep the altitude or from experience in other airplanes. Good luck on your project. Scott In a message dated 9/28/2008 12:16:45 P.M. Central Daylight Time, jeffreyb.peterson@gmail.com writes: Scott, My plane is not yet flying so I can not report on its flying characteristics. And I am NOT and aeronautical engineer. Usually people like what they are used to, and few of us have much experience in both models. It is hard to judge by testimonials. Wasn't there an EAA test pilot report on the small tail L360? If I remember the pilot found the stick forces/g to be alarmingly light. If I understand this, low f/g is not just an annoyance resulting in lack of tactile feedback, but an indication that the stall recovery will be slow. if you visualize an airplane falling in stall, it seems reasoanable that a larger tail and elevator could speed the recovery. Again, I am no expert. Thanks for bring up the issue of rebalancing. I did switch to the long mount when I changed to the the large tail. I agree it is very important not to let the CG move too far aft. At first I was impressed with how light the new carbon horiz. stab was, then I added the elevator counter weights. I made plaster molds, so I could get as much lead as far forward as possible, but still they really did add considerable weight. After changing the tail and mount I did a preliminary weight and balance and I seem to be on target so far. I will do another W and B when the cowl is done. -Jeff --------------------- Jeff, One small point. I am a satisfied user of the small tail. I took my first civil flight lesson shortly after ordering a Lancair 320 slow build kit, thus I have no military or ATP training or flight time. My airplane can be trimmed all the way to touchdown and the elevator has all the authority I have ever needed. Either you have found out by personal experience or that of others that the 300 series Lancairs are, uh, less happy fliers when the CG is located in the aft most quarter of its range. The Mark II tail alone exacerbates flight problems at rearward CGs since it adds such a large rearward moment. Thus the corollary recommendation that the long engine mount be used to move the CG forward. This is especially true if lighter props and equipment locations means the empty weight CG is not at least at the most forward point so indicated in the build manual. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Pilot not TSO'd, Certificated score only > 70%. -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html **************Looking for simple solutions to your real-life financial challenges? Check out WalletPop for the latest news and information, tips and calculators. (http://www.walletpop.com/?NCID=emlcntuswall00000001) -------------------------------1222626793 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Jeff,
 
I guess it does depend on what one is used to.  The same coul= d be=20 said about the "test pilots."  I don't know how your tail will operate=20= on=20 your airplane, but consider these observations on mine:
 
1. In trimmed cruise, pitch change is very sensitive to wee elevator=20 movements requiring little force.    
 
2.  In trimmed cruise, slowly rolling into a 15 degree banked= =20 turn requires little force.  Quickly rolling into a steep turn (45 degr= ees=20 or greater) requires a good application of side force on the stick to g= et=20 to the bank angle and thereafter no side force is required as the ailerons a= re=20 maintained in neutral.
 
3. In order to hold altitude in the steep turn without re-trimming requ= ires=20 adding heavy back pressure on the stick.  Note: For me, leaving th= e=20 cruise trim in means I know what will happen when I return to level=20 flight.
 
4. During that steep turn, the forces are reversed. The ailerons are ve= ry=20 light and the bank angle can be easily altered with slight side pressure whi= le=20 the elevator is held with some muscle.  Altering the bank angle=20 changes the back pressure needed to maintain altitude.
 
5. The forces are a bit different for left and right turns.
 
One might conclude that stick forces are not well balanced for pit= ch=20 and roll.  Kinda makes you pay attention.  Pitch changes change sp= eed=20 and speed changes change pitch - and it happens quickly.
 
Recently, I was giving a future Lancair pilot some right seat time and=20= I=20 was concerned about a characteristic I noticed in practicing slow speed= ,=20 small bank angle turns - the nose kept rising!  If there is any sensiti= vity=20 issue, it is during slow flight.  The controls are very light and it is= =20 easy to quickly creep into a bad AOA, perhaps by thinking tha= t=20 using minor back pressure will keep the altitude or from experienc= e in=20 other airplanes.  
 
Good luck on your project.
 
Scott
 
   
In a message dated 9/28/2008 12:16:45 P.M. Central Daylight Time,=20 jeffreyb.peterson@gmail.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>Scott,

My plane is not yet flying so I can not report on i= ts=20 flying characteristics.
And I am NOT and aeronautical=20 engineer.

Usually people like what they are used to, and few of=20 us
have much experience in both models. It is hard to judge by=20 testimonials.

Wasn't there an EAA test pilot report on the small ta= il=20 L360?  If I remember the
pilot found the stick forces/g to be=20 alarmingly light.

If I understand this, low f/g is not just an=20 annoyance resulting in
lack of tactile feedback,
but an indication t= hat=20 the stall recovery will be slow.  if you
visualize an=20 airplane
falling in stall, it seems reasoanable that a larger tail and=20 elevator
could speed
the recovery.  Again, I am no=20 expert.

Thanks for bring up the issue of rebalancing.
I did swit= ch=20 to the long mount when I changed to the the large tail.
I agree it is v= ery=20 important not to let the CG move too far aft.

At first I was impres= sed=20 with how light the new carbon horiz. stab
was, then I added
the elev= ator=20 counter weights. I made plaster molds, so I could get as much lead
as f= ar=20 forward as possible, but still they really did add considerable=20 weight.

After changing the tail and mount I did a preliminary
we= ight=20 and balance and I seem to be on target so far.

I will do another W=20= and=20 B when the cowl is=20 done.

-Jeff

---------------------
Jeff,

One small=20 point.  I am a satisfied user of the small tail.  I took my
f= irst=20 civil flight lesson shortly after ordering a Lancair 320 slow
build kit= ,=20 thus I have no military or ATP training or flight time.  My
airpla= ne=20 can be trimmed all the way to touchdown and the elevator has
all the=20 authority I have ever needed.

Either you have found out by personal= =20 experience or that of others
that the 300 series Lancairs are, uh, less= =20 happy fliers when the CG is
located in the aft most quarter of its=20 range.  The Mark II tail alone
exacerbates flight problems at rear= ward=20 CGs since it adds such a large
rearward moment.  Thus the corollar= y=20 recommendation that the long
engine mount be used to move the CG=20 forward.  This is especially true
if lighter props and equipment=20 locations means the empty weight CG is
not at least at the most forward= =20 point so indicated in the build
manual.

Scott Krueger AKA=20 Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

Pilot= not=20 TSO'd, Certificated score only > 70%.

--
For archives and uns= ub=20 http://mail.lancaironline.net:81/lists/lml/List.html



Looking for simple solu= tions to your real-life financial challenges? Check out WalletPop for the latest new= s and information, tips and calculators.
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