Rudder-Fuselage-Roll Correlation in the PBY 5

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BiBa
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Rudder-Fuselage-Roll Correlation in the PBY 5

Post by BiBa »

When I flew the FSX for the first time, the first question I asked a real pilot was:
when steering left with the Rudder, imagine the Rudder as the left Wing-Aileron of a plane turning clockwise 90°, and thus must cause rather a right roll (clockwise) rather than a left roll effect (anti clockwise).

The pilot replied, that it was a very smart observation to make and my logic of thinking was correct - but I forget the effect of the fuselage. When steering left with the Rudder, the plane nose turns left and with it the fuselage blocks partially the airflow beneath the left wing, which causes this left roll (against clockwise) rather than a right roll.

It was a good lesson indeed... This is also a good explenation for the tilting phenomena in the opposite direction that accures in for eg a P-51 when making in high speed a 5 G strong 70° left turn, without adjusting the nose/ fuselage with left rudder inputs to keep the nose tracking straight with the flight trajectory; the fuselage breaks the airstream beneath the right wing and causes a right tilting roll.

Now I saw recently in Medtner's thread (The DHC-2 Beaver as an Accusim-plane thread) a beautiful picture link for the Amphibian PBY 5.
http://www.flickr.com/photos/collingwoo ... 687033489/
I noticed the rudder is centered positioned to the streaming line of the wings, and the fuselage is so low, that I wondered if the rudder reaction in it is different than other standard planes, as I assume in this PBY 5, the fuselage do not block the airstream beneath the wings, and thus does not imply the same roll effect as usally expected.

This is only an assumption, that can be appropriately evaluated by a pilot who actually flew the Amphibian PBY 5 with thanks in advance for sharing his aviation knowledge with us.

If my assumption is correct, then what a pleasant plane to fly. If A2A is finally planning to design its first amphibian AI, then is this definitely the right candidate. DHC-2 Beaver is second, Grumman Goose third... We can finally take advantage of the latest Accu-Feel Add-On option of the Water Drag.
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