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By looking an image of P-40 Warhawk with taildragger (and other vintage warplanes), one can conspicuously find the propeller disc of this aircraft isn't perpendicular to the relative airflow which induces P-factor.

Doesn't this design forces the aircraft to further left which causes difficulty for pilot to direct rudder to right?

P-40 warhawks

Is this the reason why all the modern airliner's (including single engine aircraft like Cirrus SR22, Kestrel K-350) fuselage isn't made inclined?

Auberron
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  • Does this answer your question? Why tail wheel rather than tricycle? – Dave Gremlin Mar 26 '20 at 09:39
  • No, this question also addresses p-factor. – Auberron Mar 26 '20 at 10:28
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    I do not understand, you voted saying that the other question is a duplicate of yours, but commented otherwise. Also, I do not understand your reference to the p-factor, since it is a function of the AoA at the prop, not the mounting angle. – Federico Mar 26 '20 at 13:42
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    @Federico: it was accidental closure https://chat.stackexchange.com/transcript/message/53909093#53909093 –  Mar 26 '20 at 17:13
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    @ymb1 ah, I see. – Federico Mar 26 '20 at 17:20
  • @ymb1 -- title needs some help. There seems to be a verb missing. Perhaps what was meant was "What is the effect of being a taildragger rather than having a tricycle gear configuration, on the effect of P-factor?" Or, "What is the effect of P-factor on a taildragger?" Or-- ?? -- something like that? – quiet flyer Mar 27 '20 at 05:16

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By inclined, do you mean that the conventional (taildragger) landing gear configuration angles the propeller? If that is in fact your question, know that the propeller is not “inclined” in flight any more than a tricycle landing gear aircraft. Straight and level is basically (very roughly) the same between the P-40 and the SR-22. And, P-factor is only induced when the aircraft has sufficient forward motion. At very low airspeeds, there is hardly any P-factor.

In a conventional (tail-dragger) landing gear aircraft, once you are above the customary taxiing speed (the sufficient airspeed mentioned earlier), you pitch the nose forward. This raises the tail. In effect, you eliminate the “incline” in question. You are, at that point, almost flying the aircraft as if it had tricycle landing gear.

The conventional landing gear was the norm in those days. And, they were more conducive to landings on unimproved runway surfaces. Although, the conventional gear is more advantageous on non-hardened surfaces. Its biggest disadvantage is its difficulty in steering at low speeds. The lack of a steerable nose wheel means you must rely on differential braking only at low speeds and the rudder at medium to high taxi speeds.

This leaves you prone to what is called ground loops. A ground-loop is caused by the center of gravity being positioned behind the point of lateral rotation (the main landing gear in this case). Any over use of differential braking or miscalculation of the leverage applied by the long leverage arm of the rudder can cause the aircraft to violently and uncontrollably spin around. Think of trying to steer your car while driving at high speeds in reverse.

The old adage is that you have to fly a taildragger from the moment you leave the hangar till the time you park it to put it away. Tail-draggers require you to be a lot more adept on the rudder.

It also leaves you vulnerable to prop strikes due to nothing stopping the nose from over-pitching. Something very easy to do by applying the brakes too hard during roll out from landing.

Dean F.
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  • Thanks @Dean F for your lovely answer. Here is a video that shows propeller isn't inclined at the time of take-off. – Auberron Mar 26 '20 at 04:51
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    Just a couple notes here: A taildragger pilot will often take off from a "three point" attitude, in which case, P-factor continues more or less continuously from the time power is applied to the time the aircraft lowers it's angle of attack. If the pilot raises the tail for takeoff, P-factor will disappear while the AOA is lowered, but the pilot can also expect precession to pull the nose to the left while the nose is brought down, in proportion to the pitch rate, requiring more right rudder in the transition. Harvey Plourde goes through this in detail in "The Compleat Taildragger Pilot" – 2NinerRomeo Mar 26 '20 at 19:29