Talk:P-factor

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Physics: Fluid Dynamics Low‑importance

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Improvements[edit]

Further graphics are desirable to illustrate the precise relationship between a descending blade whose propeller disc is inclined to the flight path vector, and its angle of attack. A table should be added to bring the p-factor into association with other equally important propeller effects (gyroscopic, asymmetric wash and torque). (Weirpwoer 02:10, 30 April 2007 (UTC))[reply]

I am new to this concept and it took me a while to really grasp it. I could not understand why the angle of attack on the descending blade would be different than the angle of attack on the ascending blade. The lightbulb came on when I realized that, when climbing or under heavy power, the nose of the airplane rises which results in the angle of attack difference. Weirpwoer, your comment about the propeller disc being inclined to the flight path was one major contribution to my aha moment. I've added that information (along with a little less formal wording) to the "causes" section of the article. I hope you don't mind me borrowing your wording - it was very helpful to me. Thanks! Dculberson (talk) 20:22, 7 February 2008 (UTC)[reply]

Merge[edit]

A new editor has created the article Asymmetric blade effect, but both it and this article clearly state that the two are different names for the same effect. So why have two articles? Akradecki 20:17, 30 April 2007 (UTC)[reply]

The information contained here on P-factor is a sufficiently simple explanation. I would suggest replacing the article Asymmetric blade effect with a redirect to P-factor. The former had been created before realising the latter term was extant, therefore with the inclusion of alternative terms on the P-factor page it is safe to disregard a merge in favour of a simple redirect. Weirpwoer 00:54, 1 May 2007 (UTC)[reply]

Support merge Farside6 (talk) 15:38, 18 December 2007 (UTC)[reply]

WikiProject class rating[edit]

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 10:01, 10 November 2007 (UTC)[reply]

Causes[edit]

There is a discussion inside the article in 'Causes'. One person is saying something then another is saying it's not. Apart from a trashy discussion inside the article, it looks like original writing which is not contemplated in Wikipedia best pratices. --Arvoredo (talk) 01:43, 15 October 2015 (UTC)[reply]

High power settings[edit]

In the article conventional landing gear: "Some aircraft lack sufficient rudder authority in some flight regimes (particularly at higher power settings on takeoff) and the pilot must compensate before the aircraft starts to yaw. Some aircraft, particularly older, higher powered aircraft such as the P-51 Mustang, cannot use full power on takeoff and still safely control their direction of travel. On landing this is less of a factor, however opening the throttle to abort a landing can induce severe yaw unless the pilot is prepared for it." Sounds like this should be mentioned in this article, unfortunately there's no source cited. --BjKa (talk) 10:29, 19 February 2016 (UTC)[reply]

Gyroscopic precession[edit]

An editor has added the unsourced claim

Although the right half of a clockwise rotating propellor disc produces more thrust at high angles of attack, gyroscopic precession causes this thrust to act on the bottom half of the disc, 90 degrees ahead in rotation. This causes a pitch up force rather than left yaw force. Because the effect is constant, elevator trim is usually adjusted already and this pitch up is not noticeable. This leaves spiral slipstream as the predominant force causing left yaw in a climb, not P-factor of the descending propellor blade.[citation needed]

However, I've found unreliable sources which dispute this. This one says "precession of the propeller... only kicks in if we actually allow the prop to move out of its plane of rotation... So, in the case of asymmetric thrust, if we correct with rudder, and the aircraft doesn’t yaw, there will be no precession effect."

It would be good to find a reliable source with the correct answer. cagliost (talk) 15:08, 13 January 2022 (UTC)[reply]

Both could be true, i.e. p-factor would cause pitching if not prevented, but we prevent it with rudder. cagliost (talk) 13:35, 18 January 2022 (UTC)[reply]