Trim Wheel Installation Instructions for Cessna 180, Early 182, and ...

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ST02202AK-A INSTALL, Rev C Page 1 Trim Wheel Installation Instructions for Cessna 180, Early 182, and 185 Aircraft Document Number: ST02202AK-A INSTALL Revision: C 10/26/2023 FAA Project Number: SA02528AK McFarlane Aviation, LLC. 696 E. 1700 Road Baldwin City, Kansas 66006 Copyright 2023 McFarlane Aviation, LLC. 785-594-2741 696 E 1700 RD 785-594-3922 Fax Baldwin City, KS 66006 www.mcfarlaneaviation.com sales@mcfarlaneaviation.com Cessna Trim Wheel Kit Installation Instructions ST02202AK-A INSTALL, Rev C Page 2 1. Background Reports have highlighted issues with the OEM Cessna 180, early 182, and 185 trim wheels. The OEM Cessna trim wheel has a shaft with the trim wheel and sprocket pinned to it separately. There have been many cases where the pin has either sheared or fallen out completely. This has resulted in loss of elevator trim and in some cases run away trim. Additionally, the OEM trim wheel is made of a Bakelite-Phenolic material which has been known to crack at the spiral indicator grooves. This allows the indicator wire to jump grooves. In addition, this can allow the indicator wire to get caught and wedged between the grooves which could lock the trim wheel making the elevator trim immovable. McFarlane Aviation, LLC. now offers a new aluminum replacement elevator trim wheel design that alleviates the above-mentioned OEM trim wheel short comings. The McFarlane Trim Wheel design utilizes rivets to fasten the trim wheel to the sprocket ensuring that the two parts do not separate unlike the OEM trim wheel. The trim wheel sprocket assembly is pinned to the shaft, the shear load on the pin is minimized because all the torque is taken up by the rivets that mate the trim wheel and sprocket. The shaft is now free to rotate on the airframe bearings without any torque load. In doing this, the possibility of loss of elevator trim control or runway trim is greatly reduced. By manufacturing the trim wheel out of aluminum, the risk of breaking the spiral groove barrier is greatly reduced, if not entirely eliminated. This reduces or eliminates the potential of a trim indicator malfunction and a locked elevator trim wheel. The new McFarlane aluminum elevator trim wheel is a low-cost direct replacement trim wheel for the ageing Cessna 180, early 182, and 185 aircraft fleet. McFarlane Aviation, LLC. 785-594-2741 696 E 1700 RD 785-594-3922 Fax Baldwin City, KS 66006 www.mcfarlaneaviation.com sales@mcfarlaneaviation.com Cessna Trim Wheel Kit Installation Instructions ST02202AK-A INSTALL, Rev C Page 3 2. Installation Instructions 2.1. Cessna Trim Wheel Kit Parts List Ensure that you have received all the necessary parts for your kit. The table below lists all the parts you should have received with this STC. If your kit is missing any of the below parts, contact McFarlane Aviation immediately. CESSNA TRIM WHEEL KIT – Parts List Description Part Number Quantity Elevator Trim Wheel QMI-0761205-01 1 Backer Bushing QMI-0761205-02 1 Sprocket QMI-0761210-01 1 Rivet MS20470AD3-17 3 Long Shaft1 QMI-0761205-09 1 Roll Pin, .094 x .5001 MS16562-25 1 Roll Pin, .062 x .5001 MS16562-6 2 Short Shaft2 QMI-0761205-002 1 Roll Pin, .094 x .5002 MS16562-25 1 1Long Shaft and indicated Roll Pins are bagged together. 2Short Shaft and indicated Roll Pin are bagged together. 2.2. Aircraft Eligibility Before installing, use the table below to confirm you are using the correct shaft for your aircraft’s model and serial number. Cessna Aircraft Model Aircraft S/N Use Shaft: 180 Early aircraft up to 180-51607 QMI-0761205-002 (Short Shaft) 180-51608 thru later aircraft QMI-0761205-09 (Long Shaft) 182 Early aircraft up to 182-53598 QMI-0761205-002 (Short Shaft) 185 Early aircraft up to 185-0949 QMI-0761205-002 (Short Shaft) 185-0968 thru later aircraft QMI-0761205-09 (Long Shaft) 2.3. Aircraft Preparation If the aircraft has the OEM trim wheel in place, it needs to be removed. 1. Disconnect the trim cables at the turnbuckles aft of the baggage compartment. 2. Remove trim wheel cover assembly by removing attaching screws. 3. Remove the screws attaching right bearing support bracket and remove the bracket. On later serial numbered aircraft, remove the roll pins and washers at the ends of the trim wheel shaft to remove the bracket. 4. Remove the trim wheel. Disengage the chain from the sprocket as trim wheel is being removed. McFarlane Aviation, LLC. 785-594-2741 696 E 1700 RD 785-594-3922 Fax Baldwin City, KS 66006 www.mcfarlaneaviation.com sales@mcfarlaneaviation.com Cessna Trim Wheel Kit Installation Instructions ST02202AK-A INSTALL, Rev C Page 4 2.4. STC Installation To install the new McFarlane aluminum trim wheel, attach the appropriate shaft for your aircraft (see Section 2.2) to the trim wheel assembly using the provided MS16562-25 roll pin, then reverse the steps in Section 2.3 above. See the diagram on the next page for clarification: McFarlane Aviation, LLC. 785-594-2741 696 E 1700 RD 785-594-3922 Fax Baldwin City, KS 66006 www.mcfarlaneaviation.com sales@mcfarlaneaviation.com Cessna Trim Wheel Kit Installation Instructions ST02202AK-A INSTALL, Rev C Page 5 2.5. Installation Diagram McFarlane Aviation, LLC. 785-594-2741 696 E 1700 RD 785-594-3922 Fax Baldwin City, KS 66006 www.mcfarlaneaviation.com sales@mcfarlaneaviation.com Cessna Trim Wheel Kit Installation Instructions ST02202AK-A INSTALL, Rev C Page 6 3. Weight and Balance The McFarlane aluminum trim wheel STC exchange weight is negligible therefore no changes to the aircraft Weight and Balance is required after installing this STC. -END-