Rob,

From what I recall, its actually quite simple.  On the flap up side on a Lancair 320 kit, you want the flaps faired in with the fuselage.  On the down side, use the dimension identified in the plans measures from the trailing edge of the fuselage fairing.  The flaps up and down number of degrees is really an aerodynamic issue and does not specifically effect the rigging.  While it’s nice to know (faired in is 7 deg up, full down is 45 deg down), only the actual measurements from the trailing edge of the faired in position matters.  Make sure both left and right flaps have the displacement down AND are faired in to the fuselage fillet in the up position or you will get a rolling moment (AKA heavy wing).  Also, with no air load on the flaps (such as while sitting in the hangar), the flaps will droop down from the faired position as a result of the slop in the flap linkages.  When you get an airload on them, they will deflect up a bit.  You can just take your hand and force them up while in the hangar to try and get the loaded up position.  It’s a lot of trial and error.  For that matter, the whole aircraft build process it too J.

BTW, retracting the flaps from T/O position (about 7-10 deg down) to up (and faired in) has a HUGE change in airfoil pitching moment.  It will require a quick stick to keep up followed by change in your pitch trim device.  After you get some hours on the aircraft you learn to anticipate on compensate for the pitch change.  The first time you experience it (i.e. first flight), it might scare the bejeebers out of you (it did for me).

Don Gordon

N320DS – Lancair 320, 1900 hours

Orlando, FL

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.