Avstar Aircraft of Washington, Inc.

10415 172nd St. E., Hangar A1
Puyallup, WA  98374
office (253)770-9964
or (253)770-0120
email:  avstarair@att.net

01-15-2012 Ask Mike! Archive
How is the differential control mechanism rigging tool installed on an H35 Bonanza?

Hi Mike,

I have a highly technical question, the answer to which is not really explained in the Service Manual.  How is the differential control mechanism rigging tool installed on an H35 Bonanza?  I have the correct tool, per the parts manual, with the required adapter, per the parts manual.

On my plane, there is a tab on the rudder control arm that seems to line-up with center tab on the rigging tool, with holes on both tabs that line-up to allow the rigging tool to be installed to the rudder control arm at this point.  Logical.  So far so good.

From the Service Manual, it appears that the rigging tool rests forward of the bulkhead and that the ruddervator control arms are then adjusted to just touch the aft edge of the rigging tool.  (Of course, assuming the correct rudder pedal pin and control column block have already been installed.)

But then, why are there two tabs on the rigging tool located on either side of the center tab?  I'm wondering if these tabs on the rigging tool are supposed to be attached to the ruddervator control arms, where the ruddervator control tubes attach.  It could be that these tabs are for rigging an earlier model Bonanza, since this rigging tool covers a wide range of serial numbers preceding the H35 model, and are not relevant at all to rigging an H35.

Any help you can offer is appreciated.

Michael  54D, '57 H35


Attached 3 photos of the 35-590087 jig installed.  Note this is a later airplane, so the -9 adapter is also installed (If I would have removed it, the jig wouldn't fit.)  I gave you three angles so you can confirm on your bird.  If you are using the 590076 jig, I can't help you much, other than to use the photos as a guide of what you may be looking for.  The 87 jig is applicable C & up, also works well on the B and down.

 Differential Control Rigging Tool - Photo 1    Differential Control Rigging Tool - Photo 2     Differential Control Rigging Tool - Photo 3

Adjusting the ruddervator control rods will do nothing to align the jig in the aircraft.  With the rudder pedals blocked and the block in the control column, check the lower aft elevator cable length, then adjust your cables ((3) - Rudder, up elevator and forward down elevator) to proper tension and contact with the jig, then confirm your column dimension.  Once that is done, then adjust the control rods for neutral.

If you have any doubts whatsoever as to order, or the whys and wherefores of this tail rigging, I suggest 2 things:  First, the manual calls out rigging the different systems separately; that is a major waste of time if both systems need adjustment (if only one needs adjusting, it is very satisfactory).  If you do them simultaneously as I described, it works well.  Second, you need to fully understand the system and inputs for proper end result.  If you do not, get a copy of the late (V35B/F33A/A36) shop manual; there is an excellent chapter on this rigging.  Follow it, and use the numbers (tensions & travels) for your bird out of the 35 shop manual (vol. 1).

Please do not hesitate to phone if you need further clarification.


Hi Mike,

Your email and attached pictures were most helpful.  I do have the 076 jig, applicable to my serial number with an adapter, but just seeing the position of the 087 jig, particularly the manner in which it is installed to the rudder control arm, answered a lot of questions for me.

I'll keep my eyes out for a late model (V35B/F33A/A36) shop manual, just for the rigging details you referenced, of course using the applicable data for cable tensions and degree of deflection of control surfaces, etc., from the shop manual for my bird.

My plane is in annual now and I don't really have to change the rigging at this point, but I'm a Bonanza enthusiast and just love learning everything I can about maintaining my plane.  I want you to know that I work with an A&P IA, so you don't have to worry about me tinkering with my rigging on my own, but my A&P IA doesn't have the experience that you do and I totally appreciate that you took the time to provide some helpful information.

In fact, I may just come see you or at least find out your availability and cost if I do decide that my plane needs to be re-rigged.  You have impressed me with your knowledge and willingness to help an aircraft owner.

Best Wishes,
Michael L.