Mailing List lml@lancaironline.net Message #55625
From: Wolfgang <Wolfgang@MiCom.net>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: MK II Tail
Date: Wed, 07 Jul 2010 12:23:50 -0400
To: <lml@lancaironline.net>
Excuse me but I fail to see how pointing out a lack of information up front is "insulting".
What I call "insulting" is a manufacturer refusing to fix false information being advertised about their product.
 
I wasn't aware there is a requirement to search the archives to validate incomplete comments
made by someone who supposedly already knows the details but didn't give any support for their comments.
 
You point out many factors that can influence the question to some degree or another but don't quantify much.
. . . That's part of my original point. Without hard answers, the comments I referred to are just opinions.
 
Back to the point, a larger tail will allow a larger CG range, but it seems some don't mind being limited.
 
Wolfgang
 
----- Original Message -----
Sent: Tuesday, July 06, 2010 7:00 PM
Subject: Re: [LML] Re: MK II Tail

Wolfgang,
 
Please search the LML archives before you insult people that have been reporting on these characteristics and differences for years.
 
Anyway,
 
1. Every LNC2 has potentially different flight characteristics because of building variability.
 
2. No one has ever verified whether the wing was flap normal or flap reflex when the CG range was calculated.
 
3. The small horizontal may exhibit greater sensitivity than the MKII tail, but the airplane was designed with the small tail and it is effective enough if built as designed.
 
4. Every flight control is a system and if a system component is changed, it probably affects the whole system - to wit, the remaining comments:
 
a. The small tail elevator, as issued, required very little force to displace it (as opposed to the ailerons) - this leads to responsiveness or sensitivity, whichever is preferred.  Remember that LNC2's have an added bob weight to reduce sensitivity in > 1 G maneuvers (missing from 235's).  However, one additional fix was for the LNC2 builder to shorten the elevator bell crank (4" to 3"), thus increasing the required force by 25% and reducing throw movement of the stick by 25%.    Of course, the trim spring had to be beefed up as did the friction on the crucifix trim arm.  This was further helped by the Reichel geared trim wheel.  Anyone with these modifications will be pleased with the performance of the small tail.  These mods do not affect any W&B or CG issues.
 
b. Trim tabs embedded in the elevator are a totally different situation.  There are so many different size tabs with different effectiveness.  One thing elevator mounted trim tabs do is add weight to the elevator and counterbalancing weight to the horn.  This increased tail weight can affect CG because the tail arm is so long.
 
c.  Even though the MKII tail is carbon, it is additional rearward weight added to an airplane that does not like a rear CG.  The controls on the elevator may be the same as those outlined in a & b.  Lancair provided a long (3" longer) engine mount to address undesirable rearward CG issues that usually provided a 1.5" forward movement of the CG (uh, installation specific) with no ill effects.
 
d. Even small tail builders have effectively used the long engine mount because LNC2 flight characteristics can be enhanced with a more forward CG (see 2 above and within reason).
 
e. Now, take all the variability discussed above and add other combos such as header/no header, extended wingtips, extended fuel bays, battery/pump locations, yada, yada, yada................. all having some effect on W&B - CG.  See item 1 above. 
 
And you want meaningful flight differences described merely because the LNC2 is differentiated by small vs big tail?   Dreamer..................
 
Scott Krueger
IO320 lawn dart, small tail, reduced bell crank, Reichel wheel, built with a forward CG, pleased as punch.
 
 
In a message dated 7/6/2010 3:05:08 P.M. Central Daylight Time, Wolfgang@MiCom.net writes:
Most of these comments, most in favor of the small tail, fail to quantify the difference in any meaningful way . . . which is quite
aggravating.
I get the sense that "It's been that way for 50 years so why change now ?" attitude is the rule of the land.

I don't see how that is supposed to help others that know nothing of the difference understand the difference.
. . . Isn't that what this list is for ?

Wolfgang

----- Original Message -----
From: "Bill N5ZQ" <n5zq@verizon.net>
To: <lml@lancaironline.net>
Sent: Monday, July 05, 2010 9:04 PM
Subject: RE: [LML] Re: MK II Tail


> And a good plan it is too, Angier.
> I really like the small tail much better myself.
>
> Bill Harrelson
> N5ZQ 320 1,800 hrs with a small tail
> N6ZQ  IV under construction
>
>
> -----Original Message-----
>
>
> Hmmm, my kit came with the large tail and I've flown a handful of
> 320s, all with the small tail.
> I'm considering cutting off the large tail and installing a small one...
>
> Angier Ames
> N4ZQ



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