aircraft pulls to Left

[Robert Lees]

As an aside, back in WWII, the early original Rolls-Royce Merlin-powered Spitfire & Hurricane engines (c.1000-1800hp) rotated one way, and the later Rolls-Royce Griffon powered Spitfires (c.2420hp) rotated the other way; I guess that caught a few 19-year-old pilots out.

[Scott]

I understand they were good at finding the ground.

Wasn't it an iteration of the Gypsy Major that went in the Auster?

[Robert Lees]

It was, Scott, but I've avoided those upside-down in-line engines British engines with a vengeance because they're just wrong.
Sorry for the thread diversion.

[astjp2]

To get a plane in rig you need to look at more than washout (twisting the wings by adjusting rear strut length). There is a whole process to rigging a plane. If you take the twist out of the wing and the real problem is the rudder is adjusted wrong you could cause dangerous stall problems. BOTH wings trailing edges should be up compared to the root (NEVER DOWN!!!) to insure a stall starts at the FUSELAGE end of the wings.
The first thing to check is how much twist is in each wing by leveling the fuselage (measured on the horizontal stab) and then remeasuring the existing twist on both sides at the location on the drawing. ON BOTH SIDES. If both sides are the same then you adjust the rudder tab to get the plane to fly straight. Next, once the plane flys straight, you do a careful and GENTLE stall and see which wing drops. The plane "should" stall straight ahead, most don't at this point. BE READY for a wing drop! You then adjust the strut of the wing on the high side from the stall by turning the adjusting screw out a turn and fly again, adjusting the rudder again to get her flying straight. You keep doing this till the plane flys straight and stalls straight ahead or seems to go one way or the other at random (this means you are probably making rudder pedal inputs).
When you do the stalls BE CAREFUL and be prepared to apply spin recovery inputs in case your plane is REALLY out of rig! If your plane is WAY OUT of rig and has been corrected with the wrong adjustments this process can be DANGEROUS! Sudden wing stalls from mis-rigged wings can lead to unrecoverable spins.

That picture is the hard way‘as a tool that is 2 pieces of 1” 90 degree 1/8 angle, cut one 12” long rivet it vertically to another that stops at the rear spar. The install a 2” bolt with th nuts that you can winch up to the 1-5/16” and use the stabilizer as your leveling point with a digital level there. “0” it and then adjust the strut so the bottom angle is level and oriented the same as when on the elevator. Good luck to you!

[Matt]

You don't adjust the horizontal stab angles or positions because the rest of the plane is aligned to the stab, not the other way around. LEVEL in pitch is defined by the stab attach points being level. Everything in the pitch plane is measured from the stab. A rudder tab was factory equipment but I have seen MANY panes (including both of mine when I bought them) where the rudder tabs were taken off. When the fabric was taken off on both of my planes and every rudder I have had there were always screw holes for the tabs.

Does anybody know the details of the trim tabs that were installed at the factory (i.e., size and position) on the rudder? I have the same problem with left turning tendency on a BC12D with an 0200, and have tried strut adjustment as well as installing heavier spring to the pedal, both without much luck. So I think it's time for a rudder tab......

[astjp2]

Does anybody know the details of the trim tabs that were installed at the factory (i.e., size and position) on the rudder? I have the same problem with left turning tendency on a BC12D with an 0200, and have tried strut adjustment as well as installing heavier spring to the pedal, both without much luck. So I think it's time for a rudder tab......

Check your washout, if the ball is centered ant it still has a tendency to turn, then it’s a wing rig issue.

[Robert Lees]

These airframes were designed for small horsepower engines. The fin has an offset to counter the left-turning tendency of those small horsepower engines.
more horsepower (and speed) will overcome the existing fin offset, leading to either constant pressure on the right rudder pedal or use of a rudder tab.

I'm not convinced that wing rig is an issue in these cases.

Rob

[astjp2]

These airframes were designed for small horsepower engines. The fin has an offset to counter the left-turning tendency of those small horsepower engines.
more horsepower (and speed) will overcome the existing fin offset, leading to either constant pressure on the right rudder pedal or use of a rudder tab.

I'm not convinced that wing rig is an issue in these cases.

Rob

I haven’t measured an F-19 or 21, are they different than a bc?

[Robert Lees]

Hi Tim (I'm back in UK as of this morning).
Nor have I, but the F22 has a much bigger fin/rudder or course.

Like you, I wonder if the F19 (immediately after the B models) had either an increased fin area (which I doubt) or a greater fin offset to allow for the bigger engine size, or did they come with a rudder trim tab as "standard"?
On my own UK Taylorcraft with a C85 stroker, I had to fit a rudder spoiler to help with the "right-foot" syndrome.

Rob

[astjp2]

F-19 and 21 have same rudder, so I suspect the fin is the same.