Flap rigging

[Plummit]

Hi all. My -10 has had a heavy right wing since the day I bought it. I then noticed that the flaps didn't seem to deploy evenly when I tried for 1 "notch" or take-off position. The left flap would appear to drop slightly but the right didn't appear to move until I selected the 2nd position. I then noticed that the left flap was always slightly below the bottom of the fuse while the right flap seemed to be even with the bottom when fully retracted.

I check the plans section 44 but there was no info on aligning the flaps when they are fully retracted WRT the fuselage, and the amount of flap at the first position. Any help is much appreciated.

regards

~Marc

 

[Jesse]

You can adjust the flap control rid to adjust rigging. The inboard end of the flap has to be filed down to nest against the fuselage side so it can fully retract. Make sure it doesn't scrape or bind when you adjust it. Also, even if both fully nest flush with the belly skin when fully retracted, they need to drop at the same time. I usually will fully retract them then drop them for about 1 second and compare the trailing edge with the fuse bottom skin. If they are even there, you should be good. Also, when fully retracted, you can check for twist by comparing the flap spar rivets with the trailing edge of the top wing skin. It should be even the whole length.

Once you adjust flap rigging, you may need to adjust aileron rigging to be even with the flaps when fully retracted. Note that the elevator needs to be in trail when rigging the ailerons.

 

[Bill.Peyton]

If you don't already have a copy of the plans, it would be a good idea to purchase a dvd from Vans. The procedures for rigging the flaps and ailerons are contained there in.

 

[BobTurner]

d.

I check the plans section 44 but there was no info on aligning the flaps when they are fully retracted WRT the fuselage, and the amount of flap at the first position. Any help is much appreciated.

regards

~Marc

The retracted flaps are not aligned at all to the fuselage. They should be up against the aft wing spar.

 

[BobTurner]

Once you get the flaps fixed, look at the vertical height of the ailerons. Sight down the top of the wing (looking aft). The skin should flow smoothly from wing to aileron. If one aileron is even 1/32" high that wing wil be heavy.

 

[Plummit]

If you don't already have a copy of the plans, it would be a good idea to purchase a dvd from Vans. The procedures for rigging the flaps and ailerons are contained there in.

Ah thanks Bill and Jesse. I do have the RV-10 CD so I will check that out. With the flaps being off (with regard to each other) I don't trust that the ailerons will be right on either. I'll check both out this weekend.

regards

~Marc

 

[Bill.Peyton]

Marc,
The procedure is to remove the flap actuation rod at the flap. The flaps should then be moved upward, toward the fuse until they are nested in the wing. They should both completely bottom out against the wing. If one of them or both of them do not, then find the point of interference restricting the movement. Assuming they are both nested, confirm that both flaps in the same position relative to the fuselage, adjust the actuation rods and re-install them.

Once you have the flaps set, the next check would be to verify the entire aileron actuation is adjusted properly. The procedure can be found in section 23-9. To properly verify the entire aileron actuation system requires a template (P/N W730) that is provided as part of the kit. In the end, as Bob pointed out, the ailerons should be held in alignment with the flaps, and if the wingtips were fitted properly, should fall in alignment with the ailerons.

One thing to note, if you don't already know, in normal flight the Flaps on in a "Reflex" position. This means that they are actually at a negative angle. along with the ailerons and the wingtips. This is done to reduce the drag in cruise.

Once you are able to verify you have everything rigged properly you should go fly and verify you still have a wing heavy issue. You don't mention if the builder installed the aileron trim, if so, verify that it is in the neutral position and is working properly.

Something to note is the RV10 is very sensitive to fuel imbalance. I even notice a difference when I am in the plane by myself.

 

[Jesse]

Having done this on at least 10-15 RV-10's, when the flap fully nests against the wing rear spar, the bottom skin of the flap is flush with the bottom skin of the fuse. This is the 3-degree reflex position. If the ailerons are rigged above or below this point, then they are out of rig. Ailerons rigged too low or too high won't necessarily cause a "heavy wing" because the stick will move to even them out. A twisted flap, a twisted aileron or a wingtip trailing edge out of rig can cause a heavy wing. It can also be caused by an actual heavy wing either based on construction, accessories installed or fuel imbalance.

 

[Plummit]

Marc, You don't mention if the builder installed the aileron trim, if so, verify that it is in the neutral position and is working properly.

Something to note is the RV10 is very sensitive to fuel imbalance. I even notice a difference when I am in the plane by myself.

There is no aileron trim. The builder opted for rudder trim which is activated by the coolie hat on the stick. His feeling was that he used the A/P most of the time so aileron trim was less important.

I usually burn off 15 gallons from the right tank to help with the heavy wing.

~Marc

 

[BobTurner]

Just to clarify, I was referring to the leading edge of the ailerons in my post above, not the trailing edge. If one sticks up more than the other it will produce a 'heavy wing'. Vans sells an undrilled mounting bracket for just this.

 

[Jesse]

Yes, that would make a heavy wing. Also note that the RV-10 is now using the RV-14 ailerons, so there are no steel powder coated brackets any more. If you have the older ailerons you can adjust them, but not the new ones.