P factor

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P factor

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As the tail of aircraft is down, the axis of rotation is inclined. The down-going blade produces greater thrust as it is at higher angle of attack than the up-going blade. This causes asymmetric loading and aircraft making the aircraft tending to yaw.
One of the “left-turning tendencies” of aircraft with a propeller, in which the loading of a propeller disc produces more thrust on one side than the other. If the nose of the aircraft points up relative to the oncoming wind, the downward-moving blade creates greater thrust than the upward-going blade, as the former is at a higher angle of attack than the latter. Assuming that the engine is turning clock-wise as viewed from the rear (as is the case in the majority of single-engine propeller aircraft), the aircraft will tend to turn left. Also known as asymmetric propeller loading.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
That's due to factors we've already explored: reduced (or no) airspeed and the torque, slipstream effect and P-factor of high-power and low-speed conditions.
In extreme cases, sudden application of takeoff power can result in at least momentary inability to maintain directional control as the necessary crosswind compensation and the airplane's sudden increase in torque and P-factor require all available rudder travel.
It is easier to win over the people's hearts by bringing in the P-factor in an election discourse.
The p-factor can be viewed as the ratio of the number of valence p-n residual interaction to the number of valence like-nucleon-pairing interaction, or, if the p-n and pairing interactions are orbit independent, then p is proportional to the ratio of the integrated p-n interaction strength.
Observables such as E([4.sup.+.sub.1])/E([2.sup.+.sub.1]) or B([E.sub.2], [0.sup.+.sub.1] [right arrow] [2.sup.+.sub.1]) that are associated with the mean field vary smoothly with p-factor.
The goodness of calibration and prediction uncertainty is decided on the basis of the nearness of the p-factor to 100% and the r-factor to 1.
Since the P-factor should be near to 100% and the P-factor should be close to zero [30], it can be concluded that the performances of both the SMCII and SMI methods are acceptable in accordance with model uncertainty in prediction.
Calibration-validation Index analysis SMI method SMCII method NS 0.40-0.51 0.66-0.71 RMSE ([m.sup.3]/s) 50.2-36.2 36.9-27.6 P-factor 0.57-0.5 0.5-0.5 P-factor 0.16-0.06 0.18-0.17 TABLE 4: Analysis of stream flow ([m.sup.3]/s) percentiles during model validation.
The three forms of the P-factor are noted here in the aggregate.
* Traffic capacity: The number of circuits required for the stated offered traffic at a given P-factor is prescribed in standard graphic or tabular format depending on the traffic-handling formula selected--that is, Erlang B, lost calls cleared; Poisson formula, lost calls held; or a particular queuing procedure.
The combined effects of torque and P-factor will work against you even harder when the airplane naturally wants to turn in that direction in the first place.
Pilots may intentionally create yaw forces to counteract roll from engine torque when the aircraft is moving slowly through the air; counteract the yaw from propeller-generated p-factor when flying with a high angle of attack; slip the aircraft to intentionally create drag; and align the aircraft with the runway when slipping to counteract crosswind drift.