Pilot Loses Control When Worn Aileron Cable Snaps During Landing (PA-18-150)

[Neal]

I've thought about this scenario but have not practiced a rudder/elevator only control in the event of loss of aileron.

Pilot Loses Control When Worn Aileron Cable Snaps During Landing — General Aviation News

Probable Cause: Maintenance personnel’s failure to detect the worn aileron cable during the most recent inspections, which resulted in the separation of the aileron control cable and a subsequent loss of airplane control during landing.

generalaviationnews.com

 

[ve6yeq]

Ignoring the very poor quality of maintenance leading up to the breakage…

I have mainly practiced control holding ailerons neutral and with just rudder and elevator during slow flight and stall recovery and sometimes during cruise when trimmed out (flying hands free in smooth air) but never on final approach…

I was thinking that you could approach it by slowing down and doing the falling leaf to the ground with just a small amount of power to soften the landing. However, if just one of the cables broke, then would the remaining tension in the system not pull the aileron in one direction so you would need to use the other aileron to try and balance the drag in addition to using the rudder to keep the wings level?

 

[Cactus Charlie]

However, if just one of the cables broke, then would the remaining tension in the system not pull the aileron in one direction so you would need to use the other aileron to try and balance the drag in addition to using the rudder to keep the wings level?

I don't know how the system behaves when one aileron direct cable fails. If the ailerons tend to lift with flight loads then the crossover balance cable prevents both deflecting up.

Unless the ailerons are perfectly matched aerodynamically I would expect one to lift and the other to be pulled down by the balance cable. The pilot reported a roll right and stick full left with no tension. I doubt he tried stick right.

The aileron cable system is shown in this Piper drawing. I don't know if there is an equivalent CubCrafters drawing but I think the EX/FX system is identical. X and NX have a completely different aileron system using pushrods.

I suspect the EX/FX would behave very differently for roll control with rudder with a broken aileron direct cable than when the cable loop was normal.

The accident pilot had wind gusting to 28 kts and some pilots can't handle that even with all controls working.