01/29/2009 Ask Mike! Archive Page
Rigging Questions

Hi,

Would you know where the aileron should sit relative to the flaps while in straight and level flight?  My Beech Bonanza, a '67 V35, came from annual and the left aileron is about two inches below the flap and the right about 1 inch.  The yoke sits at a 30 degree counterclockwise position in straight and level as well.

Mike P.

Mike,

Sounds like someone goofed.

When rigging a 35, the flaps should be rigged first, to come all the way up looking at the position of the forward flap rollers in the tracks (there are small round inspection covers adjacent to the tracks on the lower wing surface to get a visual look at this).  Note:  this is contrary to one of the ABS tech reps that continually states the flaps should be even with the bottom of the fuselage - that is incorrect, but may be how it works out on some aircraft.

Next the ailerons are rigged.  The neutral position is inboard end of aileron matched with outboard end of flaps with control yoke centered.  Should be that way in straight and level flight also.

Left (counterclockwise) yoke should raise the left aileron.  The ailerons should move 20 degrees from neutral, both up and down.  I wouldn't fly the aircraft until it has been re-rigged according to the 35 Shop Manual, including travel and cable tensions.

You didn't mention if you had asked them to look at any rigging issues during the annual.  On a properly rigged (by the book) Bonanza with no deflection of the fixed aileron tabs, if in straight and level smooth air flight, you 'let go' of everything, it should remain stable.  If it doesn't, pay attention to what happens first:  If the aircraft yaws, the elevator trim tabs can be adjusted to correct that.  If it rolls first, it is a wing adjustment.  (Sounds harder than it is.)  Under no circumstances should a flap be 'dropped' to compensate for roll tendencies.

Gear Green,
Mike

Mike,

Thank you for your response.  It was very concise and helpful.  I had not asked that any rigging or controls be adjusted prior to the annual.  However, talking to the mechanic yesterday, he stated on inspection of the left aileron inboard hinge a prior improper placement of some bolts had taken place by someone.  Somehow, these bolts were not going through some holes as he explained to me.  Apparently when he replaced the bolts properly, it must have drawn up the aileron to a different adjustment or position than it had been previously.  This is apparently why the rigging was different when I received it after annual.  I briefly explained to him the manner in which you had described the proper rigging should be done and he said he would probably get  to it in the next day or so.

I'm hoping we can resolve this issue with the next visit to the shop.  Thank you so much and maybe I can drop in sometime when I am over in Washington.  If we can not get it resolved here, I will definitely be over to have you look at it.

Mike P.

Hi Mike;

The misalignment of the left aileron would be explained by the screws not catching the hinge.  Good thing that was caught, but they should have noted if that created a rigging issue.  Doesn't explain the right aileron.

Would still recommend the re-rig before flight, as an improperly rigged aircraft will fight itself in the air, and may cause controllability issues.

Gear Green,
Mike

Hi Mike,

You are correct on having the rigging issue addressed before flying it.  I had not realized there was a problem until I flew it to Seattle right after the annual.  I initially thought we had too much luggage on the right side of the aircraft, but found out that was not the problem.  If a left roll maneuver would have been necessary due to wind gust, etc.  I would have been hard pressed to correct it....(especially during takeoff due to P-factor).

Mike P.