Mailing List lml@lancaironline.net Message #61612
From: <Sky2high@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] LN2 reflex position
Date: Sat, 14 Apr 2012 00:01:40 -0400
To: <lml@lancaironline.net>
Rob,
 
When I slow built my 320 from 1989 to 1996, the construction manual noted that the inboard faired in position was -7 degrees and the full extension was 45 degrees - the limits of flap movement.
 
Please note that the slow build construction manual I received in mid-1989 was an edited 235 document with many dimensional errors in it.  Also note that the 235 flap faired in position is 0 degrees and thus the recommended cruise position (certainly for operation above 160 KIAS) was to reflex the flap up above the 235 faired in position.  In that case, does -7 degrees = 5/8"?  It is possible that your manual is this sort of transitional instruction set that was not completely edited from the 235 to the 320/360 airframe.
 
I later purchased the 320/360 fast build manual that was much better for that kit - in that case it was missing details for those things "slow" built by the "factory."
 
Also note that after building the flaps I found that, with the plane leveled (both in pitch and laterally), the TE fuselage fair tip differed vertically by 1/2" - thus, the left wing was slightly different than the right and flew left wing "heavy."  This problem was fixed by slightly altering the flap rigging so that when retracted the left flap was a bit higher than faired and the right a bit lower (maybe a half turn on the push rod end for each flap).
 
Finally, certain cross country racers (myself included) tried setting the flap further above the -7 degrees for increased race speeds.  Generally, such experiments did not result in any increase in speed.
 
Scott Krueger
N92EX
 
PS There is a FB manual available as a pdf.  It is rather large.  However, here is a flap rigging page.
 
In a message dated 4/11/2012 9:51:59 P.M. Central Daylight Time, stevens5@swiftdsl.com.au writes:

Folks,

 

A question for you experienced L320/360 builders. I am building a kit in Australia, which I purchased partly built some years ago. It is listed as “Kit 304”. However, it was a kit produced in Australia by a company building under licence from Lancair, in about 1990, so I don’t know how thekit number relates to what you use in the USA. My query relates to rigging the flaps. The builder’s manual seems very confusing, as I will explain below.

 

·         On page 10-20 at paragraph 12, it states “The flap should have a travel range from 5/8” T.E. up (from faired in position at the inboard fillet) to full down”                         

·          

·         On page 10 -21 at paragraph 14, the diagram indicates full down occurs with the T.E. of the flap 8 ¾” down from the “faired in position”.

 

 

·         On page 10-24, in the top paragraph, it states “Lancair flaps…are designed to run from +45deg down to -10deg up (reflex). Note that the “faired in position” for flaps and ailerons on the plane is actually a  -7deg reflex position” (On my aircraft, 45deg down from the faired in position gives the specified 8 ¾” downward deflection at the flap trailing edge).

 

·         On page 18-19, at paragraph E 1, it states “The up limit stop should be set to the faired in position (which is -7deg on the Lancair 320’s) . The 320’s are designed to be faired in for cruise which is actually 7deg reflex for the aerofoil. Thus for take-offs, you will appear to visually drop 10 – 12deg of flaps and slowly fair back in for cruise settings”.

 

Maybe I’m stupid, but this all seems incredibly confusing to me. My question is, what is the relevance of the statement that the travel range should be from 5/8” T.E. up, if you are at full reflex at the faired in position? Do they require the flap to have the ability to go to 5/8” T.E. up, but then never actually use it?

 

Hope someone out there can help. Really appreciate everyone’s input.

 

Regards,

 

Rob Stevens

Perth, Western Australia.

 

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