Image 2 shows the amount of rolling force depending on which engine is inoperative. Now lets look at what happens when each of the engines are inoperative. This creates a rolling effect to the left. The image shows the amount of induced lift with the light blue arrows. The greatest induced drag on the right wing, is further from the CG that the greatest induced drag on the left wing. Now that we understand what P-factor is, we can better understand accelerated slipstream, since it is produced by P-factor.Īs a result of P-factor, stronger induced lift is produced on the descending blade by its prop wash. If you look at image 2, you will see the effects of P-factor when each of the engines is inoperative. Failure of the left engine will cause more loss of directional control than the loss of right engine because of the longer arm of the right engine's thrust from the CG. The yaw produced by the left engine being inoperative will be greater than the yaw produced by the right engine being inoperative, making the left engine the critical engine. P- Factor causes a conventional twin to yaw to the left. This is the same aerodynamic factor and concept, but lets see how it effects a multi-engine aircraft.Īt low speeds and high angles of attack (like take-off), the descending blade (right blade) produces more thrust then the ascending blade (left blade), as shown by the light blue arrows in image 1. The descending blade on the right engine has a longer arm from the CG than the descending (right) blade of the left engine, creating a yaw force to the left. ![]() You learned about P-Factor when you were learning about the left turning tendencies of a single engine aircraft. We've discussed the definition of a critical engine, lets discuss how we determine which engine is the critical engine. You will experience different performance and handling qualities depending on which engine fails. ![]() When you lose one engine, you will experience all sorts of different forces acting against you. Now lets think of a multi-engine aircraft with an engine on each wing. Thus if the engine goes out, the only forces you have is a loss of thrust in the center of the aircraft (and of course lift). In a single engine plane, the engine is in the center of the plane. Now that we have all that out of the way, lets start thinking about this a little more. To break it down further, think of the critical engine as being the engine that will cause the most trouble for you if it were to fail. Vmc is the minimum controllable airspeed at which directional control can be maintained with the critical engine inoperative. Oh boy, so what's the critical engine then? The Critical Engine is the engine that when failed most adversely affects the performance and handling qualities of the airplane (FAR 1.1). First off, you'll find that there are a few new V speeds that you aren't used to with single engine airplanes. However, with more power comes more responsibility and understanding. What's better than an airplane with one engine? An airplane with two engines of course.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |