Keith Lane
Pattern Altitude
I went out for a little practice in the pattern tonight and got a surprise.
This is on a C-172 "L" model with 40 degree flaps.
On the second pattern, I went to set the flaps at 10 degrees. My flap system requires you to hold down the switch for about 4 seconds or so then release. Look at the indicator and it's right at 10 indicated. Now, I have a few hundred landings in this plane and I usually first watch the flaps start out before I look back at the indicator. Only this time the flaps didn't move. I remember two or three years ago, I had the circuit breaker trip once while doing this and I just reset it, and all was well.
Tonight I decided to just make a no-flap landing instead, and all went well. On the ground I looked and sure enough, the breaker was sticking out, and I reset it. The switch was in the neutral, or middle position, and after 10 seconds or so, I noticed the ammeter take a very short, sharp negative excursion and the breaker trips again.
So, I taxi back to my spot, shut the avionics master off, shut down the big fan out front, and before turning off the master, I just reset the breaker. 5 or 10 seconds later it just trips again. I shut off the master, and tied it down and went home. A call to the mechanic, and he says he's pretty sure the flap motor has gone and died on me. I wonder though, if the motor has power to it all the time, and what you are doing is switching the ground back and forth to reverse the motor. Otherwise how come it trips the breaker when the switch in in the center position. Anyway the A/P was at home when I called his cell, and he did not have the books in front of him at the time.
Anybody here have any experience or wisdom they'd like to share on this?
Thanks
This is on a C-172 "L" model with 40 degree flaps.
On the second pattern, I went to set the flaps at 10 degrees. My flap system requires you to hold down the switch for about 4 seconds or so then release. Look at the indicator and it's right at 10 indicated. Now, I have a few hundred landings in this plane and I usually first watch the flaps start out before I look back at the indicator. Only this time the flaps didn't move. I remember two or three years ago, I had the circuit breaker trip once while doing this and I just reset it, and all was well.
Tonight I decided to just make a no-flap landing instead, and all went well. On the ground I looked and sure enough, the breaker was sticking out, and I reset it. The switch was in the neutral, or middle position, and after 10 seconds or so, I noticed the ammeter take a very short, sharp negative excursion and the breaker trips again.
So, I taxi back to my spot, shut the avionics master off, shut down the big fan out front, and before turning off the master, I just reset the breaker. 5 or 10 seconds later it just trips again. I shut off the master, and tied it down and went home. A call to the mechanic, and he says he's pretty sure the flap motor has gone and died on me. I wonder though, if the motor has power to it all the time, and what you are doing is switching the ground back and forth to reverse the motor. Otherwise how come it trips the breaker when the switch in in the center position. Anyway the A/P was at home when I called his cell, and he did not have the books in front of him at the time.
Anybody here have any experience or wisdom they'd like to share on this?
Thanks
