Menu Sign In Contact FAQ
Banner
Welcome to our forums

Are all piston aircraft assymetric?

Just been reading Stick and Rudder… Apart from needing some heavy sub-editing, it’s a great book.

To deal with torque, precession, etc, it is said that the engine and the vertical stabiliser are mounted assymetrically. And even the left wing may be rigged with a greater AOA.

But, on the TB20, this isn’t obviously visible. OTOH it does have a rudder trim.

Administrator
Shoreham EGKA, United Kingdom

On many planes you can see that when aiming along Spinner and engine

...
EDM_, Germany

In the days of free-flight models, the engine always had about a 3 deg offset to the right.But not too much, lest it flew straight and was never seen again!

EGBW / KPRC, United Kingdom

On the single Comanche the engine is several degrees out of centre to the right. The Dornier DO27 fin is off centre about 3 degrees to the left and if my memory still works the L.H wing of the C-206 is couple of degrees greater AOA than the R.H side.

To understand where Langewiesche was coming from, take a look at this contemporary Ercoupe installation. There is in my experience nothing easier to fly than an Ercoupe, and the design reflected a great deal of what was written in the book (or vice versa!) In addition to the rightward-facing engine, the thrust line is angled downward to counteract the tendency of the nose to rise with increased power.

My plane (not an Ercoupe) has a noticeably assymetric vertical stabilizer orientation set up for feet off at cruise power, and no rudder trim. Yesterday when climbing from sea level to 7500 ft at max rate airspeed, not cruise climb in this instance, my right leg got tired!

Last Edited by Silvaire at 16 Feb 21:56

Ben what is your source for differing angle of incidence on the C206? Its not mentioned in Wings for the World the helpful history on the type development of the Cessna single engine aircraft. The book discusses the spin testing for the 205/206, with the different configurations (skis, floats, belly pods, parachute dropping) – the size of the test pilot and engineering team at Cessna in the heyday of light single production was impressive.

Typically you either have a fin or engine offset, differing angle of incidence between one wing and the other seems a recipe for unhelpful stall characteristics.

Enstone (EGTN), Oxford (EGTK)

You should see the rudder of a Saab Safir. It’s like a cork screw.

Seems to me things like that was popular 50+ years ago. Today, electrically operated trim tabs is a better solution. Not sure about the engine.

The Rotax in the Europa shall be installed with an offset of 1,5 degrees to the right to achieve a straight cruise flight. However I still have a rudder-trimtab and it certainly depends on power setting, how much rudder has to be applied. Also the fuselage of the Europa is very short, which doesn’t helb either for a stable direction.

Well it’s a pilot’s airplane finally

EDLE

Looking at a Cessna Caravan from the front you will see that the engine and propeller is clearly offset from the longitudinal axis. Understandable to cope with the slipstream.

Sweden

CEssna 210s & 206s incorporate another little trick: the right elevator is slightly offset from the left !

FAA A&P/IA
LFPN
34 Posts
Sign in to add your message

Back to Top