Yoke Sprocket

[Larry Lyons]

OK tribe, I have a question. I am, along with rebuilding my 41BC, am helping rebuild a 46 BC. During routing of the yoke and cables in the fusalage the other night we found one chain sprocket had two small round knobs welded in place on the back side of one sprocket. We could find no reason or use for them. Can anybody tell me what they are there for? The system works fine with them in any position, we just wonder why they are there. Larry

[astjp2]

Re: Yoke Sprocket

they are the limit stops for the chain on the Yoke. It should be mounted on if I remeber correctly, on the right side and so it acts as a stop. I think mine has the knobs mounted towards the tail of the aircraft. Hope this helps. Tim

[Robert Lees]

Re: Yoke Sprocket

These are the control limit stops for aileron travel. The sprocket with the lugs should be fitted on the pilots side of the control "H-Frame", which has corresponding lugs to limit the rotational travel. (If the other sprocket is also so fitted, it's not a problem).

This is why external control locks should be used if your Taylorcraft is parked outside.

[Dick Huish]

Re: Yoke Sprocket

Larry, every time I see your avatar it brings back a lot of memories. I worked on a lot of Navy Jets including the F-8's. Dick

[hangarb7]

Re: Yoke Sprocket

Don't forget that there is an AD on these buttons:

Regulatory Information
78-20-11 TAYLORCRAFT: Amendment 39-3314. Applies to Model BC-12D, Serial Nos. 6923, 8376, 8444, 8570, and 10538, and Model F-19, Serial Nos. F-080 through F-105, F- 107 through F-112 and F-115 through F-126 certificated in all categories.

To prevent malfunction of the aileron controls, accomplish the following:

(a) Inspect the two aileron stop pins (Taylorcraft P/N A-235) of the aileron control assembly (Taylorcraft P/N A-A231) prior to next 10 hours time in service after the effective date of this AD or by December 1, 1978, whichever occurs first. The assembly is located on the left side of the control column at the forward end of the control shaft and universal joint. Determine whether the stop pins are AN393-9 clevis pins as follows: Remove the deck panel (above instrument panel) and set control wheel in neutral position. In this position aileron stop pins will be on top. The proper pins (2) are identified by the flat head of the pins against front face of the sprocket. The flat head is cut partially to clear chain and obtain smooth operation of control. The shank of the stop protrudes approximately 1/4". If the sprocket has AN393-9 clevis pins, no further action is necessary.

(b) If the pins are made from 3/16" diameter rod (no head), inspect for the following:

(1) Bent pins

(2) Loose pins

(3) Inadequate protrusion (less than 1/4") of pin through aft of sprocket or improper functioning.

(c) If any of the conditions identified in (b) above are present, replace the sprocket prior to further flight.

(d) If the AN393-9 clevis pin is not installed and none of the three conditions in (b) are found, replace the sprocket within 50 flight hours or by May 1, 1979 with a sprocket in which clevis pins (AN393-9) have been installed. Until the sprocket is replaced, reinspect within 10 hours time in service from last inspection. A proper sprocket may be obtained from Taylorcraft Aviation Corporation, 14600 Commerce N.E., P.O. Box 243, Alliance, Ohio 44601.

Taylorcraft Bulletin Number 78-002 dated September 19, 1978 also applies to the subject matter of this AD.

This amendment becomes effective October 16, 1978.

>>This is a relatively easy AD to confirm.

Good luck,

Jack Dernorsek
N44057
BC12D