Incidence. The angle of incidence can refer to a number of entities: in optics, the angle of incidence is the angle that the incident ray makes with the line drawn perpendicular from the point of contact on a surface. 26 Aircraft Leveling Set-up: Theodolite – dipasang 2 meter didepan hidung pesawat (nose fuselage); Theodolite … Used to determine the correct mounting angle for wings. So, here is my method to calculate the wing incidence during the building process. Check the height of each wing tip. Incidence. I decided to check the wing incidences. 2. If the angle of incidence is 0 degrees, then that would require a nose high attitude and expose more of the underside of the fuselage to the relative wind. First I set the plane on the level ground, then propped the plane up on a box until it looked like it was perfectly level. A given wing requires a certain angle of attack (pitch up attitude) in order to fly at a given weight and speed.
Last full rib incidence -.717 Wing washout 2.56 PA12 Level at floor between gear fittings +1.665 Butt rib incidence -.060 Last full rib incidence -2.627 Wing washout 2.567 Tolerance is +/- 1/4 degree. This is why you used the guage close to the fuselage before.
Check the angle at the tips and close to the root of both wings. If not then make adjustments to the wing saddle until the incidence is correct. 26 Aircraft Leveling Set-up: Theodolite – dipasang 2 meter didepan hidung pesawat (nose fuselage); Theodolite … 01/12/2016 24 Longitudinal and Lateral Datum Lines . Any twist in the wing would have made your wing angle leveling step useless otherwise. Use a 30" straight edge on the rib bottoms between the spars to account for the curve in the ribs. So I figure it is a thrust alignment issue or wing incidence. 01/12/2016 2 . This short tutorial about wing incidence and the flight attitude, is an English translation of my work in the French Forum Retroplane. TOPIC: How do you check the incidence of each wing. Yesterday's post on the Vought F-8 Crusader brought up an interesting design parameter - the angle of incidence. Recheck the vertical stabilizer. So, get your bottom wing set at zero, then check the top wing. Used to determine the correct mounting angle for wings. The Crusader has a variable incidence wing. Datum Lines and Datum Points 01/12/2016 25 . 23 AIRFRAME RIGGING - CHECKS 01/12/2016 LBP .

At this point you should check the wing incidence. Setting the wing at an angle helps in keeping the drag low for the given lift. Do not continue until you have done this because it is easiest to adjust before the leading edge dowels are in place. Wing twist is an aerodynamic feature added to aircraft wings to adjust lift distribution along the wing.. Often, the purpose of lift redistribution is to ensure that the wing tip is the last part of the wing surface to stall, for example when executing a roll or steep climb; it involves twisting the wingtip a small amount downwards in relation to the rest of the wing. Use the wing template to cross-check the aileron and flap alignment. If it is correct then you can move along to the next step. Parallel to a line running from wing-tip to wing-tip. If there is no or minimal (get real, less than ½”) sweep fore or aft, then move on to #4 below. 23 AIRFRAME RIGGING - CHECKS 01/12/2016 LBP . At the same time, triangulate from each wingtip to some center point on the aft fuselage. Anyway.. the incidence on a bipe really refers to the wings relation to each other, not so much in relation to the rest of the fuse. Keep the level in the same orientation and with the same shims at the same spot on the level. 01/12/2016 24 Longitudinal and Lateral Datum Lines . There is much debate about the correct angle of incidence required for efficient flight but a good starting point is to have the horizontal stabiliser and wing both at zero angle, then adjustments can be made after flight tests. For the original article, in French, check here . How do you check the incidence of each wing. At slow speeds, the front of the wing lifts up, increasing the angle of incidence. Hang 2 plumb bobs on each wing, one at the tip and one at the root (tank area).

Is it up the middle of the airframe? We do want to check that the wings don’t have any twist in them. Now check the forward sweep! Here is my simple home made wing incidence meter. The springs and steering bungees should center the rudder when the nose gear is off the ground. Datum Lines and Datum Points 01/12/2016 25 .