I read here some time back that a number of us have had stuck flaps due to blown flap relays. I remember being grateful that I had been spared this presumed random failure.
2 days ago my flaps got stuck and I think I know why — unintended/uninformed operator error.
Turns out that you can’t begin to raise the flaps until they’re 100% down and locked. Any premature movement of the switch may send excess voltage through the relay and blow it out. If it does, the flaps are stuck.
CD is anticipating installing more robust relays going forward but in the meantime, don’t be impatient like I was during a pre-taxi check to ensure the flaps weren’t frozen. Don’t move that flap switch till flap movement is fully stopped.
Joe,
Great input, I’ll make a note on my checklist, as it is an easy trap to fall into!
Han
I read here some time back that a number of us have had stuck flaps due to blown flap relays. I remember being grateful that I had been spared this presumed random failure.
2 days ago my flaps got stuck and I think I know why — unintended/uninformed operator error.
Turns out that you can’t begin to raise the flaps until they’re 100% down and locked. Any premature movement of the switch may send excess voltage through the relay and blow it out. If it does, the flaps are stuck.
CD is anticipating installing more robust relays going forward but in the meantime, don’t be impatient like I was during a pre-taxi check to ensure the flaps weren’t frozen. Don’t move that flap switch till flap movement is fully stopped.
Hi Joe,
Activating the flapswitch to retract the flaps while they are traveling out in my opinion easily can be a factor in case of a relay blowup.
However, I had a different experience last august with the N137CD.
On final, with the flaps locked on 50% and expanding them to 100% we heard a loud bang somewhere beneath which we could not place at that moment but what later appeared to be the relay blowup.
I’m sure the flaps where not retracting at that moment as no one would do on final.
Replacement of the relay fixed the problem within a few minutes as the relay is easily accessible under the right backseat.
Carrying a spare one is a cheap solution for a quick rapair in case of.
Happy new year and many happy landings to all of you.
Jan Stevens (#469)
I read here some time back that a number of us have had stuck flaps due to blown flap relays. I remember being grateful that I had been spared this presumed random failure.
2 days ago my flaps got stuck and I think I know why — unintended/uninformed operator error.
Turns out that you can’t begin to raise the flaps until they’re 100% down and locked. Any premature movement of the switch may send excess voltage through the relay and blow it out. If it does, the flaps are stuck.
CD is anticipating installing more robust relays going forward but in the meantime, don’t be impatient like I was during a pre-taxi check to ensure the flaps weren’t frozen. Don’t move that flap switch till flap movement is fully stopped.