Re-Rigging

[Kerbs]

My plane has never flown straight on its own, if you let go of the yoke it would slowly enter a right bank. I finally took the time to re-rig the plane over the weekend. My horizontal stabilizers were quite a bit out of level and the wings were washing opposite directions. Going through the re-rigging process took a little time and a lot of double checking but it made a huge difference. I can let go of the yoke and cruise all day long and the plane goes where it's pointed. Plus I picked up 2-3mph in cruise. I'd highly recommend anyone that has not been through the process in quite some time to take a few hours and check your rigging.

[Edwin Otha]

Lots of people use the phrase it fly's hands off. Doesn't mean it's rigged correctly. The tail needs to be perpendicular to each other and square to the longitudinal axis of the plane. I set the wing at the same incidence angle and fly it. Adjust the heavy wing.

EO

[Hank Jarrett]

It is a process. Sometimes a really complex one, but a lot of fun if you approach it with the right attitude. Dton't forget that after a few hours things can "relax" and shift around some. It is well worth doing another rig after 10 hours or so. If nothing moved, it will go pretty quick. If something DID move you will already know how to fix it since you just did it recently. There is something magic about a properly rigged plane. It comes to life in your hands.

[PA1195]

Yes and the vertical stabilizer incidence L or R of fuselage centerline should be checked. Look or run a string forward from the tail over the top of the stabilizer CL and see where it intersects the roof or skylight over the cockpit. That offset can be used sometimes to rig in flight cruise. Piper's can be offset to the left slightly.

Gary

[Scott]

The fin on the BC12D, as with most single engine aircraft, is offset to the left at the leading edge. This counteracts the tendency for the aircraft to yaw to the left due to the rotation of air from the propeller.

The target is normally to have the aircraft straight in yaw at 75% power ie cruise power. Note that if you're operating at any other power setting, right or left rudder is needed to fly straight/coordinated.

Rob will no doubt note that the fin offset is (leading edge) to the right on British powered aircraft because they spin the other way!

[Robert Lees]

...Rob will no doubt note that the fin offset is (leading edge) to the right on British powered aircraft because they spin the other way!

And some Canadian ones (Chipmunk springs to mind!)

[Edwin Otha]

Level the plane laterally and make sure the stabilizers are level. Position the fin 90 degrees to the stabilizer. I generally find the tail square to itself, but crooked to the aircraft. This induces a roll into the aircraft that people will compensate with aileron tabs, some pretty big! The airplane fly's "hands off" but it's flying in a skid.

EO

[Scott]

And some Canadian ones (Chipmunk springs to mind!)

Yes, British engine!
a joy to fly, but a little mind over matter is needed to reverse rudder inputs eg left foot during take off/climb.

[Robert Lees]

Yes, British engine!
a joy to fly, but a little mind over matter is needed to reverse rudder inputs eg left foot during take off/climb.

You are right in that's it's a British engine (the Blackburn Cirrus and derivatives, inverted straight-four, leading up to the Gipsy Queen S6)
A lot of aviation people still think the Chipmunk airframe is of British design, but it's not. Well-educumicated folk like all here on this Forum know that de Havilland Canada designed it, and also many of the most useful back-country workhorses in the modern world.
Their only mistake was calling it DHC when it should be dHC...that's why much later models were called purely by their dash number (eg -8)!
Not a lot of people know that!

I've flown a Gipsy Major-powered Chipmunk, only a few times; it's a delight to fly (like a poor man's Spitfire), but I would never be able to afford the maintenance costs!

Rob (sorry for the thread drift)

[For further historical context:
All these European in-line-four-cylinder engines were developed from the original German Benz engine of the late 1800s. Hence lots of very early European aircraft developers using similar. The Brits, the French, German, Italian and Polish and other designers all made their own refinements over the subsequent decades. The Brits were the first to turn one upside-down to improve the view over the nose...my Aeroclub's first aircraft was an Avro Avian in 1919 ]

Further edit1: Henry Ford also adopted the upright in-line-four-cylinder engine for the Ford Model A (and later T): some of those engines were (and still are) used on the likes of Bernie Pietenpol's designs like the Skyscout and Pietenpol

Further edit2: It is generally understood by most that the horizontally-opposed flat-four was developed by the German Volks (people) company in the mid 1930s to reduce weight & complexity, but still delivering the same power, but it was a two-cylinder. We know it by the name "Beetle".

The French also developed the two-cylinder opposed engine for their farm vehicles (later to become the deux chevaux , 2-CV [2 horsepower]), still in use today.

[astjp2]

start with a straight and square tail, then correct washout, fly and then minor adjustments from there. no more than one turn at a time at the rear lift strut, in one turn on one side, fly out a half or one on the other. Mine has no tabs and flies ball centered and straight for hundreds of miles hands off...

[Scott]

One useful trick, the rudder springs can be used in lieu of a tab on the rudder. Add a tailwheel chain link to the spring on the pedal you don't need to rest your foot on to fly straight.