Triplane stunt

[sleepy gomez]

I don't seem to be able to post attachments of small photos.  If anyone is interested email me at: sleepygomez@gmail.com and I'll send them direct.

[Clancy Arnold]

I am posting this for Sleepy.  Clancy

TRILOGY is a triplane designed for stunt, no not for expert or advanced but for beginner and intermediate.  As pictured it has not been flown.  I waited until construction was finished for photos so as not to use up too much band width.  I like to take all the pictures before the first flight.  I’m not a good pilot.  I will post how, when and if TRILOGY flies.   Wing area is 897 sq in.  Didn’t make target weight of 66 ounces, it weighs 72 ounces.  Engine was a bargain OS Max SF 61 at 24 ounces with extra head gasket and muffler.  This is the best reason to use a short, short nose design.  Airfoil is flat back 16.4 percent thick with high point at 24 percent and uses a stock SIG leading edge..  The top view perspective makes stab look larger. The TVC is 4.6.  One photo shows the alignment sticks clamped in place to align wings, quite a chore.  The main wing struts are 3/8” dowel with auxiliary struts ¼” dowel.  The head on shot shows the vertical wing spacing of 8” measured at airfoil centerline.  May look a bit odd, but large vertical wing separation makes wings more efficient.  There is no wing stagger.  As shown, I make my own elevator control horn as well as bellcrank.  Both are strength tested as mounted.  The 6 ounce tank is mounted inboard of the engine (short nose again).  I used Monocote for the first time in 40 years.  I’ll now go back to silkspan and tissue.  This is the first plane I have built when not using wing and stab foam construction since my FF days in the mid 1970s.  It has been a fun project, SLEEPY.

[Tim Wescott]

Why stop at three?

[sleepy gomez]

Hi Tim, What would a many multi wing plane look like when there was enough vertical wing separation for the wings to be efficient?  On TRILOGY the measurement from the high point of the top wing's airfoil to the same on the bottom wing is 16 1/2", about as far I as I felt comfortable  going.  The wings should have some amount of efficiency at this spacing.  Having no wing stagger helps too. Center wing, engine centerline and stab are all in a line and equidistant from the top and bottom wings.  It has been quite a project not having used balsa and Monocote construction in 40 years.  I'll take the first flight. After that if Trilogy survives I'll find a good flier.  SLEEPY

[Jim Fruit]

Why stop at three?

Tim:

At the '72 Glenview Nats, I saw a fellow try to fly a sesqui in scale(not an octo like your sample shows). And yes, it folded up like an accordian just like the original did.

Jim Fruit