Landing Gear Trailing Edge Modification

Wednesday, Dec. 16, 2015

I've been waiting on control system parts so I decided to do the landing gear trailing edge modification which lengthens the trailing edge and changes the angle to reduce drag. It also allows for a larger brake line conduit for braided stainless steel brake lines. I followed the guidelines outlined in Wayne Hicks' Website for this modification.


 

First I had to cut off the old trailing edge at the correct location to avoid cutting through all the plies of glass from the original layup. After cutting of the old trailing edge I wrapped the trailing edge with 2 plies of BID overlapping 2 inches on each side.


 

To get the correct angle of the new trailing edge Wayne devised a simple method by measuring the distance at the top of the gear leg from vertical and this measurement is used to prop of the gear leg when shaping the trailing edge foam.

Prior to adding the foam blocks to the grear legs I fabricated a conduit for the brake lines by glassing two plies of BID over a 5/8 inch OD vinyl tube taped to the gear leg. Once the layup was cured I could remove it from the gear leg and remove the vinyl tube and then I epoxied the 2 ply BID conduit back on to the gear leg. I did this because I couldn't find any ready made flexible thin walled conduit. Outlined in red.


 

I used some 3M spary to attach sandpaper to the gear legs to shape the foam blocks.


 

Attaching the foam blocks with poar foam was messy and fun.


 


 

Per Wayne Hicks' instructions I made a sanding tool which makes the sandpaper vertical to the table and with the gear propped up at the correct height based on the measurement I could sand the topside of the gear leg foam blocks.


 

To sand the foam blocks on the bottom side I attached a piece of plastic pipe to the sanding tool and glued sandpaper to the plastic pipe.


 

I glassed the top side with two plies of BID at a 45 degrees. 1 inch of the trailing edge foam was removed for a glass to glass trailing edge.


 


 


 


 

The bottom side of the glass to glass trailing edge is filled with micro to create a tapered edge.


 

I increased the fuselage opening to allow for a 1/4 inch gap per Mark Zeitlins recommendation.


 

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