Flaps stuck!

[John Wasserburger]

David,

I can move the left flap all the way down, but it appears to bind/stick a little when lowering. Is this normal? Also, the steel rollers appear to be very dry and not lubricated. The temperature is now above 20 degrees F. and the flaps are operating normally. Maybe they need to be lubricated? I am not sure what the feel should be when lowering the left flap manually by hand.

John

[David Pyle]

You are testing the extent of my technical knowledge. Go with the previous posts. Clean and lube all the moving parts you can see, but find a warm place to do it.

[Rick Ludwin]

I had this happen several times on takeoff. Found middle roller guide was pinching roller. There was a slight indent on the guide. Smoothed this out and added lithium grease with no problem for several years. Problem recurred few years later. Greased again and problem gone. Now I keep hand on flap switch when retracting. If assymetric retraction noted I'm ready to stop to prevent too much lift.
Rick

[9089P]

Hi,

I know there is a school of thought that the flap tracks themselves should not be lubricated, roller bushings yes, track no. Mine are dry. Last yr we got our commercial licenses in the comanche. When doing the slow flight maneuver, upon recovery and retraction of the flaps, the left flap stuck and we got an asymmetrical condition. Even with the full power slow flight conditions it is manageable although uncomfortable. We recycled the flaps and it came up fine, perhaps more airspeed did the trick.

Went to the A&P to investigate and figured we would replace the retraction springs since we had it apart. What we found was that the morons who painted the a/c several years before had not reinstalled the flaps correctly. This didn't come as a big shock as we have been running into insidious little problems since then. The fact that they tried to install the brand new Johnston tips upside down is also a clue. Springs were fine but replaced anyway. Lubed the rollers and all has been well since and slow flight on the check ride was a non-event.

Good luck, Don

[Charlie Tripp]

John,
Flush the flap track and rollers with carburetor cleaner available from any auto parts store. If you feel you must lubricate the rollers use silicone spray lubricant so it will not attract dust and dirt.

[9089P]

Thanks Charlie, I should have said that silicone spray was what we used on the rollers.

Don

[MULEFLY]

I believe that there is a Service bulletin that says the flap springs should be replaced every 500 hours... not completely sure on that, but Matt Kurke knows... Mine hadn't been changed "forever".
Jim

[Zach Grant L1011jock]

Jim,
Not a SB, and not the flap springs, but close! Actually the service manual says to replace the down lock springs on the landing gear whenever you replace the bungees. So the Bungees are required by AD to be changed every 3 yrs or 500 hrs, so there shouldn't be an old spring on any of the landing gear. As for the flap return springs, I think I'd want to follow a similar replacement schedule for the flap retract springs as they are very similar springs.

-Zach

[John Wasserburger]

I have my annual next week and will replace the flap return springs and install new Delrin flap rollers. By the way, I have flown in more really cold weather and could not duplicate the problem. Thanks for all the input!

John W.

[John Wasserburger]

Just as a follow up: I installed Delrin flap rollers and now the flaps operate smooth as silk!! The steel rollers were pretty dirty and sticky when they were removed.

John W.

[N3322G]

John,

Glad to hear it was something 'simple' to fix.