Elevator Trim Troubles
From Serial number 1623 on Ercoupes were fitted with an Elevator trim that included a movable trim tab.
The trim is actuated by the pilot through a lever that pushes a wire through a cable housing that ends adjacent to the trim tab. This wire will get stuck at times due to several reasons.
- It can become rusty or
- the housing can get kinked thus kinking the wire.
The remedy is in most cases to replace the wire, or if the wire is still straight and not broken, by pulling the wire out, cleaning and greasing it and replacing it.
A job that does not take too long and is easily done under the supervision of your A&P.
A situation that ruins your flying day. A broken trim wire.
You can pull out the wire to the rear after straightening the broken off piece.
It helps to loosen the last piece of the housing at the stabilizer root under the fairing. It is almost certainly necessary to open there when putting the new wire in, because the wire might get stuck at the joint. Plus this is a good access point to insert more grease to make it easier to remove & reinsert the wire.
Reconnect at the front and rear ... and you are ready to go.
Make sure not to over tighten the little attachment fastener at the back and front end of the wire.(like in this picture) They should be left to pivot freely, not be tightened down so much that it doesn't pivot. Otherwise the wire will be bent and will break soon again.
Linda
Alternative oiling method - maybe the first step before pulling the wire
Here is the procedure:
- disconnect the cable from the swivel
- slip a one inch rubber hose over the cable housing
- secure the hose with the cable opening inside with a simple hose clamp making sure the end is tightly sealed
- pour four/five ounces of lubricant (we used Mouse Milk--available on Aircraft Spruce) into the open end of the hose
- hold or attach compressed air hose to open end tightly
- pull the trigger allowing the forced air to push the lubricant all the way through the hose, lubricating as it goes. (Probably a good idea to put a cloth on the place where the trim cable is attached on the side of the plane covered by upholstery to catch any excess.) Takes about five minutes and works well.
Rick